ML17347A387

LER 87-010-00:on 870306,reactor Manually Tripped Due to Loss of Turbine Load.Caused by dirt-induced Grooves in Stub Shaft of Control Oil Sys.Turbine Control,Lube & Seal Oil Piping Will Be replaced.W/870403 Ltr

ML17347A387
Person / Time
Site:	Turkey Point
Issue date:	04/06/1987
From:	Salamon G, Woody C FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-87-151, LER-87-010, LER-87-10, NUDOCS 8704130236
Download: ML17347A387 (6)

Text

REGULATORY . FORMATION DISTRIBUTION SY -M <RIBS)

ACCESSION NBR: 8704130236 DOC. DATE'. 87/04/06 NOTARIZED: NO DOCKET FACIL: 50-250 Turkey Point Planti Unit 3i Florida Power and Light C 05000250 AUTH. NAI lE AUTHOR AFFILIATION SALAMON> G. Florida Power h Light Co.

WOODY'. O. Florida Power 5 Light Co.

RECIP. NAME RECIPIENT AFFILIATION SUB JECT: LER 87-010-00: on 870306> reactor nianual 1 y tripped due to loss of turbine load. Caused by dirt-induced grooves in stub shaft of control oil sys. Turbine controls lube 5 seal oil piping thrill be replaced. W/870403 ltr.

D I STR I BUT ION CODE: I E22D COP I ES RECEI VED: LTR ENCl S I ZE:

TITLE: 50. 73 Licensee Event Report (LER) i Incident Rpti etc.

NOTES:

RECIPIENT COPIES RECIPIENT COP IES ID CODE/NAME LTTR ENCL ID CODE/NAME LT TR E"'C L PD2-2 LA 1 1 PD2-2 PD 1 1 McDONALDp D 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 1 1 ACRS WYLIE 1 1 AEOD/DOA 1 1 AEOD/DSP/ROAD 2 2 AEOD/DSP/TAPB 1 1 NRR/ADT 1 1 NRR/DEST/ADE 1 0 NRR/DEST/*DS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 NRR/DEST/ICSB 1 1 NRR/DEST/MEB 2 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 NRR/DEST/RSB 1 1 NRR/DEBT/SGB 1 1 NRR/DLPG/HFB 1 1 NRR/DLPG/GAB 1 1 NRR/DOE*/EAB 1 1 NRR/DREP/EPB 1 1 NRR/DREP/RAB 1 1 NRR/PMAS/ ILRB 1 NRR/PMAS/PTSB 1 1 02 1 RES SPEIS> T 1 1 RGN2 FILE 01 1 1 EXTERNAL: EQhQ GROHz M 5 5 H ST LOBB Y WARD LPDR 1 1 NRC PDR NSIC HARRIS> J } NSIC MAYSi G TOTAL NUMBER OF COPIES REQUIRED: LTlR 41 ENCL 39

NRC Form 344 U.S. NUCLEAR REOULATORY COMMISSION IB 83)

APPROVEO OM 8 NO, 315(LOIOe EXPIRESr BI31IBE LICENSEE EVENT REPORT ILER)

FACILITY NAME'(1) DOCKET NUMBER (2) PA I Turkey Point Unit 3 0 s 0 0 02 501oFp3

"""" Manual Reactor Trip Following Loss of ectrsca oad Oue to Mal functionin Turbine Governor EVENT DATE (5) LER NUMBER IS) REPORT DATE IT) O'THER FACILITIES INVOLVED LE)

EEQUENTr*L REVrerON FACILITYNAMES DOCKET NVMBERISI MONTH OAY YEAR YEAR K% NUMEER ee> tpir NUMEEsi MONTH OAY YKAR A 0 5 0 0 0 0 3 0 6 87 87 010 00 0 4 0 6 87 NA 0 S 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T 0 THE REOUIREMENTS OF 10 CF R (): ICneck one or mo ~ of the followinpf (11 OPERATINO MODE (4) 20.402(b) 20.405(c) 50.73(el(2) (tv) 73,7104)

~ OWER 20AOSI ~ )Ill(il 50.34(cl(11 50.73(e)(2)(el 73.71(c)

LEVEL p 9 20.405(e)(1) IEI 50.34(e) (2) 50.73(e) (2)(vill OTHER ISpecify in Abstract below end in Ter I, HRC Form 20.405 ( ~ II I l(till 50.73( ~ ) (2)(il 50,73( ~ l(2)(viil)IAI SBBAI 20A05(el)1) (Iv) 50 73(el (2) IE) 50.73( ~ ) (2) Iviii)IB) 20.405( ~ l(1) (v) 50.73( ~ l(2)(iii) 50.73( ~ ) (2)(el LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE Gabe Salamon, Compliance Engineer 305 46- 13 00 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED Ist THIS REPORT IISI MANUFAC MANUFAC.

CAUSE SYSTEM COMPONENT TVRKR TO NpROS NX cW+(9(Prgw.:

4'&48)cw<oerrF<'yrN C USE SYSTEM COMPONENT TVRER TG 65 W12 0 N

'~44~@+4kg SUPPLEMENTAL REPORT KXPECTEO (I ~ I MONTH DAY YEAR EXPECTED SU 8 M I SS I 0 ril DATE II Si YEs Ilf yfL complere ExpEcyED sUBMlssloN DATEI NO ABSTRACT ILlmlt ro tcOO speces. I.e.. epproeimerely Irfreen slnple specs rypewntren Irnesl (14)

ABSTRACT On March 6, 1987, at 2140, with Unit 3 at 95X power, the reactor was manually tripped following a loss of turbine load. At 2138 with the control rods under manual control, a planned load reduction had commenced to investigate turbine vibration. At 2140, the Generator Motoring Trip alarm actuated, and electrical load had dropped, from approximately 698 MW to 0 MW, without any decrease in reactor power. In anticipation of a generator/turbine/reactor trip, the Reactor Control Operator (RCO) tripped the reactor. The cause of the loss of electrical load was a malfunction of the governor control oil system. The cause of the malfunction was dirt induced grooves in the stub shaft of the control oil system. The turbine control oil, lube oil, and seal oil piping will be cleaned during the next refueling outages for each unit. The impeller stub shaft and sleeve will be replaced, and the governor control block will be overhauled during the present refueling outage on Unit 3. An Event Response Team was formed and will continue to evaluate further corrective actions.

8704130236 870406 PDR ADOCK 05000250 8 PDR NRC Form 345 I9 83 I

NRC For 3BBA U.S. NUCLEAR REOULATORY COMMISSION (9 B3)

LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPRO(/ED OMB NO. 319)WIOA EXPIRES: 8/3(/(8 FACILITY NAME (I) OOCKET NUMBER (2) LER NUMBER (B) PACE (3) levl5rorr YEAR SN sEQUENTIAL:w%

NVMBER, 'e. NUMBER Turkey Point Unit 3 o so oo250 8 7 0 1 0 0 0 0 2 oF TEXT /// more Rreee /I /rer/e'e/ Iree /(/or'I 'en/I HRC %%drm Jr/I/A 3/ (12)

EVENT On March 6, 1987, at 2140, with Unit 3 at approximately 95X power, the reactor was manually tripped following a loss of turbine load. At 2138 on March 6, 1987, with the control rods under manual control, a planned load reduction had commenced to investigate turbine vibration. At 2140, the Generator Motoring Trip alarm actuated. The actuation of this alarm indicated that turbine stop valves or control valves in addition to the reheat stop valves or intercept valves. had gone shut, resulting in steam flow to the turbine being secured and therefore a loss of generated power.

This alarm also indicates that if the conditions causing the alarm persist for 30 seconds, a generator trip would occur. At this time the operators noticed that the indicated turbine electrical load had dropped from approximately 698 MW to 0 MW, without any decrease in reactor power, due to the control rods being under manual control, and no trip conditions being present. In anticipation of a generator trip and subsequent reactor/turbine trip, the Reactor Control Operator (RCO) tripped the reactor. Subsequent to the event, the unit was stabilized in hot standby.

CAUSE OF EVENT The immediate cause of the manual reactor trip was loss of turbine electrical load, due to turbine governor control oil pressure system malfunction. Grooves worn into the turbine stub shaft (see LER 250-86-039) in concert with stub shaft motion relative to the impeller oil sleeve following the minor load change resulted in a rapidly fluctuating impeller oil pressure change. This resulted in actuation of the auxiliary governor anticipatory overspeed protection of dumping control oil pressure and loss of turbine load.

ANALYSIS OF EVENT ~-

A post trip review was performed to assess the proper operation of the safety related equipment. The post trip review established that the transient behavior of pertinent plant parameters for the reactor coolant system (RCS) and steam generators responded as expected for a transient of this kind. Specifically, the RCS pressures and temperatures were determined to have followed an expected pattern based on the conditions leading up to the transient. Other than the manual reactor trip, there were no manual or automatic Reactor Protection System or Engineered Safety Features actuations. Based on the above, the health and safety. of the public were not affected.

NRC FORM 3BBA

NRC Forrr 3SEA US. NUCLEAR REOULATORY COMMISSION (9431 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3150M(04 EXPIRES: S/3(/BB FACILITY NAME (11 OOCKET NUMBER (2l LER NUMBER (dl PACE IS)

YEAR SEOVENYIAL REVISION NVM ER r~..I'VMSER Turkey Point Unit 3 0 5 0 0 0 P 5 0 8 7 0 1 0 0 0 0 3 OF 0 3 TEXT (IImuru Spree ld ruquuud, uru Additional NRC Form 3d(L( Si (12l CORRECTIVE ACTION

1) A post-trip review was completed and no abnormal operating conditions associated with the trip were identified.

2) The impeller stub shaft and oil sleeve will be replaced during the current Unit 3 refueling outage.

3) The governor control block will be overhauled during the current Unit 3 refueling outage.

4) The turbine control oil, lube oil, and seal oil piping will be cleaned during the present refueling outage for Unit 3 and the 1988 refueling outage for Unit 4.

5) An Event Response Team was formed and will continue to evaluate possible further corrective actions for the turbine control oil system.

ADDITIONAL INFORMATION Turbine Governor Manufacturer: Westinghouse. Serial (((13-A-2893 Similar occurrences: LER 250-87-009, LER 250-86-039.

NRC FORM SSSA (943(

APRIL u 3 1987 L-87-l5I IO CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gent lemen:

Re: Turkey Point Unit 3 Docket No. 50-250 Reportable Event: 87-IO Date of Event: March 6, l 987 Manual Reactor Trip Following Loss of Electrical Load Due to Malfunctionin Turbine Governor The attached License Event Report is being submitted pursuant to the requirements of IO CFR 50.73 to provide notification of the subject event.

Very truly yours, g,/~z'QO.

Woody Group Vice President Nuclear Energy COW/SDF /gp cc: Dr. J. Nelson Grace, Regional Administrator, Region II, USNRC Senior Resident Inspection, USNRC, Turkey Point Plant SDF I /003/I A+II V II 4 m My CompBi~ll %

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