ML18004B883

LER 87-037-00:on 870621,manual Reactor Trip Initiated from 30% Power After Operating Main Feedwater Train Tripped. Caused by Failed Open Feedwater Pump Recirculation Valve. Circuit Repaired & Plant Returned to svc.W/870717 Ltr

ML18004B883
Person / Time
Site:	Harris
Issue date:	07/17/1987
From:	Hudson O, Watson R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-870466-(O), LER-87-037, LER-87-37, NUDOCS 8707240005
Download: ML18004B883 (7)

Text

NRC Form 300 U.S. NUCLEAR REGULATORY COMMISSION (04)3)

APPAOVEO OMS NO. 31604104 EXPIRES: 0/31/00 LICENSEE EVENT REPORT ILER)

FACILITY NAME (I) DOCKET NUMBER (1) PA E SHEARON HARRIS UNIT ONE 0 5 o 0 o 40 0>OF03 TITLE (4)

MANUAL REACTOR TRIP TRIP OF OPERATING MAIN FEEDWATER PUMP AT 30% POWER EVENT DATE (5) LE A NUMBER (0) REPORT DATE (7) OTHER FACILITIES INVOLVED (Dl MONTH 'OAY SEQUENTIAL ofjX REVtelON MONTH FACILITYNAMFD DOCKET NUMBER(S)

YEAR YEAR @ NUMBER rrVMDER OAY YEAR 0 5 0 0 0 0 6 2 1 8 7 0 3 7 0 0 07 17 8 7 0 5 0 0 0 OPS RAT I NO THIS REPORT IS SUBMITTED PURSUANT T 0 THE REDUIREMENTB oF 10 cFR (): (check one or more of the folloeyfnPI (11 MODE (0) 20.402(b) 20A05(c) 50.73(e)12) (lvl 73.71(0)

POWER 20.405( ~ )(I)(I) 50M(c) (I ) 50.73(sl(2Hv) 73.71(c)

LEVEL (10) 20.405(v ) (I I (0 I BOM(c) (2( 50.73(sl(2) (rD) OTHER (Specify In Ahrtrect he/ow end In Text, NRC Form 20.405(s)(I) liil) 50.73( ~ ) (2)(l) 50.73(e H2)(riB)(A) 30EAI 20A05(s) 0 ) (Ir) 50.73( ~ l(1)(ll) 50.73(s) (2) (rillI (0) 20,400(s) (1)(vl 50.73(s(12) (ill) 50.73(s) (2) Ix)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE

0. N. HUDSON SENIOR ENGINEER 9 19 362 -23 63 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC. EPORTABLE MANUFAC. EPORTABL TURER TO NPAOS CAUSE SYSTEM COMPONENT TUREA TO NPRDS SUPPLEMENTAl. REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SUBMISSION DATE (15)

YF s IIIyer, complen ExpfcTED svshtlssloH DATEI NO ABSTAACT Iilmlt to f400 rpecer, I.e., epproxlmetely flfrnn tinplecpece typewritten linnl (10)

ABSTRACT On June 21, 1987 at 2208, a manual reactor trip was initiated from 30% power after the operating main feedwater train tripped, resulting in a loss of main feedwater. The motor-driven auxiliary feedwater pumps started as required.

Plant response to the reactor trip was as expected, and the plant was stabilized in Mode 3.

The trip of the feedwater pumps was caused by a failed open feedwater pump recirculation valve, resulting from open circuit in the valve control wiring. The circuit was repaired, and the plant was returned to service on June 22, 1987.

8707240005 8070717 000400 PDR ADOCK PDR S

NRC Form 300 (04)3)

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NRC Form 3MA US. NUCLEAR REGULATORY COMMISSION (983)

LIENEE ENT REPORT (LER) TEXT CO. NU N APPROVED OMS NO. 3150-0104 EXPIRES: 8/31/88 FACILITYNAME (I) DOCKET NUMSER (21 LER NUMBER (6) PACE (3)

YEAR .~ REVISION N'EOVENTIAL I;RP.

SHEARON HARRIS UNIT ONE NVMSER NVMSER p p p p p 40 087 0 3 7 0 0 02 pF 03 TEXT/EIIRsssFscoEI/s9v)Isd, INS //T/ooo/HRC%%dnII355AE/(IT)

DESCRIPTION On June 21, 1987, the Shearon Harris Nuclear Power Plant was operating at approximately 30X reactor power under steady state conditions. Power was being maintained at this level for the purpose of establishing secondary plant chemistry parameters prior to increasing power level. "A" Condensate Pump (CP), "B" Condensate Booster Pump (CBP), and "B" Main Feedwater Pump (MFP) were in operation. "B" CBP was in manual control maintaining 400 psig suction pressure to "B" MFP.

At approximately 2207, a "Condensate Pump discharge low pressure" alarm was received on "A" CP. The alarm was immediately followed by a trip of the operating Condensate Pump ("A" CP), Booster Pump ("B" CBP), and Feedwater Pump

("B" MFP). The operators attempted to restore feedwater flow by start'ing "B" Condensate Pump, but "B" CP would not start due to the position of its discharge valve. Therefore, a manual reactor trip and turbine trip was ordered at 2208 due to a loss of feedwater flow. The Auxiliary Feedwater (AFW) Pumps started as designed on, the trip of the running MFP. The plant stabilized at normal no load pressure and temperature. A routine post trip shutdown followed. After investigation of the trip, reactor startup commenced at 0100 on June 22, 1987.

CAUSE:

The post "B" feedwater trip investigation found that a fuse in the control circuit for the pump recirculation valve had failed open. This caused the recirculation valve to fail open and placed excessive flow demands on the Condensate Pump and Booster Pump.

The post trip investigation found an open circuit in a fuse in the control power to air operated valve 1FW-39; the recirculation flow control valve for the "B" MFP. This valve is normally closed at 30K power and its failure would have placed an extra 5000 6000 gpm flow demand on the running feedwater train. The normal feedwater flow at 30X power is approximately 9000 gpm', the capacity of a single condensate pump is 12,000 gpm. The total flow demand exceeded the capacity of the running CP and CBP and resulted in operation of these pumps at run out conditions. The exact sequence of the pump trips could not be determined, but the net result was the loss of the running feedwater train.

The fuse was examined. It did not appear that the filament was broken but it did not appear that it had opened as a result of a short circuit. The circuit was tested and no further deficiencies were found. It was concluded that the failure was the result of a random failure of the fuse. Equipment operation was normal after replacement of the fuse.

'NRC FORM SSSA *U.S.GPOO988~26.5%9455

'83)

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NRC Form 368A U.S. NUCLEAR REGULATORY COMMISSION (983)

LIIGSEE ENT REPDRT (LERI TEXT COOINUII>N APPROVED OMB NO. 3150-0104 EXPIRES: 8/31/88 FACILITYNAME (ll DOCKET NUMBER (2l LER NUMBER (6) PAGE (3) yEARQIOISEOUENTIALg~REVISION I NUMBER 'vYS NUMBER SHEARON HARRIS UNIT ONE o s o o o 40 87 0 37 0 0 03 oF 0 3 TEXT /P/mNB N>>c>>)r /BEUEBd, rroo ec //I/or>>/NRC Ferrrr 3//SAE/ (IT)

ANALYSIS This'vent is being reported in accordance with 10CFR50.73(a)(2)(iv) due to initiation of the reactor protection system.

There were'no safety consequences as a result of this event other than a challenge of an Engineered Safety Feature, the AFW System. The AFW pumps started as required, and were available to provide feedwater to the steam generators. The plant response described in this LER is similar to an event that is reported'n LER 87-005-00.

CORRECTIVE ACTIONS The broken fuse was replaced.

'NRC FORM BBBA *U.S.GPO:(988 0 824 538/455

'983)

CARL I 0 Carolina Power 5 Light Company HARRIS NUCLEAR PROJECT P.O. Box 165 New Hill, NC 27562 JUL I c 1807 File Number.'SHF/10-13510C Letter Number.'HO-870466 (0)

U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT'EPORT 87-037-00 Gentlemen.'n accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report fulfills the requirement for a written report within thirty (30) days of a reportable occurrence and is in accordance with the format set forth in NUREG-1022, September, 1983.

Very truly yours, R. A. Watson Vice President Harris Nuclear Project RAW:skm Enclosure cc'. Dr. J. Nelson Grace (NRC RII)

Mr. B. Buckley (NRR)

Mr. G. Maxwell (NRC SHNPP)

MEM/HO-8704660/PAGE 1/OS1

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