ML18022A571

LER 87-051-00:on 870831,main Feedwater Pump a Tripped Due to Feedwater Oscillation.Caused by Feedwater Sys Design Problems.Valve Stem Repaired & Feedwater Sys Changes to Improve Reliability Under evaluation.W/870930 Ltr

ML18022A571
Person / Time
Site:	Harris
Issue date:	09/30/1987
From:	HUDSON O N, WATSON R A CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-870504-(O), LER-87-051, LER-87-51, NUDOCS 8710060387
Download: ML18022A571 (8)

Text

REGULATORY'ORMATION DISTRIBUTION 8 M (RIDS)'ACCESSION NBR: 8710060387 DOC.DATE: 87/09/30 NOTARIZED:

NO FACIL: 50-400 Shearon Harris, Nuclear Power Plant>Unit 1>Carolina AUTH.NAME AUTHOR AFFILIATION HUDSON>O.N.Carolina Power 4 Light Co, WATSON>R.A.Carol ina Power 8c Li gh t Co.RECIP.NAME RECIPIENT AFFILIATION DOCKET 05000400

SUBJECT:

LER 87-051-00:

on 870831>main feedwater pump A tripped due feedwater oscillation.

Caused bg feedwater sos design problems.Valve stem repaired 0 feedwater sos changes to improve reliability under evaluation.

W/870930.ltr.DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR+ENCL/'IZE: TITLE: 50 73 Licensee Event Report (LER)>Incident Rpt>etc..NOTES: Application for permit renewal filed.ta 05000400 RECIPIENT ID CODE/NAME PD2-1 LA BUCKLEY, B COPIES LTTR ENCL 1 1 1 REC IP IENT ID CODE/NAME PD2-1 PD COPIES LTTR ENCL 1 1 INTERNAL: ACRS MICHE!SQN AEOD/DQA AEQD/DSP/ROAB DEDRQ'RR/DEST/CEB NR R/DEST/I C SB NRR/DEST/MTB NRR/DEST/RSB NRR/DLPG/HFB NRR/DQEA/EAB NRR/DREP/RPB NRR/PMAS/ILRB RES DEPY GI RES/DE/EIB EXTERNAL: EGS.Q GRQH, M LPDR NSIC HARRIS>J 1 1 1 1 1 1 1 2 1 1 1 1 1 2 1 1 1 1 1 1 1 2 1 1 ACRS MOELLER AEOD/DSP/NAS AEOD/DSP/TPAB NRR/DEBT/ADS NRR/DEST/ELB NRR/DEST/MEB NRR/DEST/PSB NRR/DEST/SQB NRR/DLPG/GAB NRR/DREP/RAB

/SIB REQ 02 RES TELFORD>J RQN2 FILE 01 H ST LOBBY WARD NRC PDR NSIC NAYS>G 2 2 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 TOTAL NUMBER OF COP IES REQUIRED: LTTR 44 ENCL 43 NRC Form 38$'0;83)LICENSEE EVENT REPORT{LER)U.S.NUCLEAR REOULATORY COMMISSION APPROVED OMB NO.31504)104 EXPIRES: 8/31/88 FACILITY NAME (Il SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NUMBER (2)PA E 3 0 5 0 p p4 00 1OFO'UXILIARY FEEDWATER SYSTEM ACTUATIONS ON MAIN FEEDWATER PUMP TRIPS DUE TO DESIGN AND E UIPMENT FAILURE MONTH DAY YEAR EVENT DATE ISI YEAR LER NUMBER (8)SFOUSNTIAI.

'rgb NUMBER REVISION NUMBER MONTH DAY YEAR REPORT DATE (7)DOCKET NUMBER(S)r 0 5 0 0 0 FACILITY NAMES OTHER FACILITIES INVOLVED (8)31 87 8 7 0 5 1 0 0 9 3 0 8 7 0 5 0 0 0 OPERATINO MODE (8)POWE R LEYEL 0 0 20A02(B)20A05(~l (1)(B 20.405(e)(1 l(ii)20.405(~Ill((i)i)20A05(~)(1)(Iv)20.405(e)(I l(v)20.40S(cl 50.38(cll1) 50.38(cl(2) 50.73(e)l2)(0 50.73(el(2l(ill 50.73(e l(2)(Iii)X 50.73(e)(2)(ivl 50,73(e)(2)(v) 50.73(e)(2)(vip 50,73(e l(2)(v)it)(Al 50.73(e)(2)(viii)(Bl 50.73(~)(2)(x)THIS REPORT IS SUBMITTED PURSUANT T 0 THE REOUIREMENTS OF 10 CF R ()l/Check one or more of the IOIlovfinP)

(11 73.71(B)73.71(c)OTHER (Specify in At)street below enrf In Test, IVRC Form 366A/LICENSEE CONTACT FOR THIS LER (12)NAME 0.N.HUDSON, SENIOR ENGINEER-REGULATORY COMPLIANCE TELEPHONE NUMBER AREA CODE 919 362-2 63 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)CAUSE SYS'EM COMPONENT MANUFAC-TURER REPORTABLE TO NPRDS.B)S 1?R..~,V,'I CAUSE SYSTEM COMPONENT MANUFAC.TURER EPORTAB LE TO NPRDS X S J FC VM 120 Y))o:.(l?o&~?:ia Ni SUPPLEMENTAL REPORT EXPECTED (14)YES (If yes, complete EXPECTED SIIShtISSIDII DATE)NO ABSTRACT ILlmlt to f400 specer, Ie., epproeimetely fifteen slnpre spree typetnritten Ilnesl (18)EXPECTED SU 8 M I SS ION DATE (15)MONTH DAY YEAR Abstract On August 31, 1987, the Shearon Harris Nuclear Power Plant was performing a Technical Specification required shutdown due to excess unidentified leakage (see LER-87-050-00).

At 0408 with the reactor at 8/power, the"A" Main Feedwater Pump (MFP)tripped due to a feedwater oscillation.

The root cause is Feedwater System design problems.Both motor-driven auxiliary feedwater (AFW)pumps started as required on loss of feedwater, since the"A" pump was the only MFP in operation at the time.MFP"B" was started at 0716 on August 31 and AFW was secured.At approximately 1530 on August 31, while the unit was in Mode 3, the"B" MFP tripped and AFW actuated.A restart attempt was made on the"B" MFP at 1703, but the pump tripped immediately.

AFW actuated again.The cause of the trip was a separated valve stem on the"B" MFP recirculation valve.The valve stem was repaired.Feedwater system changes to improve reliability are being evaluated.

Both MFPs were returned to service on September 1, 1987.8710060387 870930 PDR ADQCK 05000400 S PDR NRC Form 388 ro.srvi

NRC Form 300A (94)3)LICENSEE EVENT REPORT (LER)TEXT CONTINUATION U.S.NUCLEAR REGULATORY COMMISSION APPROVED OMB NO.3150-0104 EXPIRES: 8/31/BB FACILITY NAME (1)SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NUMBER (2)YEAR LER NUMBER (5)SEQUENTIAL NUMBER REv/BICN NUMBER PAGE (3)TEXT/K/rrcro<<>>ce/my/rr/ror/

r>>o r/8/or>>/NRC Forrn38549/(IT)

Descri tion of Events 0 5 0 0 0 4 0 8 7.0 5 1 0 0 0 2 OF 0 r On August 31, 1987, the Shearon Harris Nuclear Power Plant (SHNPP)was performing a plant shutdown required by Technical Specifications due to exceeding 1 gallon per minute (gpm)unidentified Reactor Coolant System (EIIS:AB)leakage (see LER 87-050-00).

Only one train of main feedwater (EIIS:SJ)was in operation.

At 0408 on August 31, with the reactor (EIIS:AC)at 8X power, the"A" MFP tripped.Both motor-driven (MD)auxiliary, feedwater (AFW)pumps (EIIS:BA)started on the loss of the only running MFW pump as required.The turbine generator (EIIS:TB)was removed from the grid and the reactor shutdown per plant procedures.

The"B" AFW pump was secured at 0425;the"A" pump was left running.The following actions were taken to investigate why.the MFP tripped.1.A p).intout of feedwater parameters during the time of the pump trip was obtained from the plant computer.From this printout, it appears that a high discharge pressure condition existed on the"A" MFP and caused it to trip.This was induced by a feedwater oscillation.

2.A work ticket was issued for Instrumentation and Control (ISC)personnel to check the setpoints on the"A" MFP high discharge pressure switches.A calibration check on one of the four discharge pressure switches showed that no significant drift had occurred since the last calibration.

As a result, no other pressure switches were checked.The"A" MFP was restarted at 0303 on September 1, 1987 and ran normally.Meanwhile, the"B" MFP was started at 0716 and the"A" AFW pump was secured at 0819 on August 31.At approximately 1530 on August 31, while the unit was in Mode 3 (Hot Standby), the"B" MFP tripped.As required, both MD AFW pumps started.The"B" AFW pump was secured at 1532, and the"A" pump remained running.At 1703,'restart attempt on the"B" MFP was made from the Control Room, but the pump tripped immediately.

As required, the"B" MD AFW pump started (the"A" MD AFW pump was still running).The"B" MD AFW pump was secured at 1704.Investigation of the"B" MFP trips revealed a separated valve stem on the"B" MFP recirculation valve (Masoneilan International Inc.Model f37-40412-8A-6").

The valve was repaired and"B" MFP was returned to service at 1620 on September 1, 1987.NRC FORM 300A (943)*U.S.GPO;1988 0 824 538/455 NRC Form 366A (943)LICENSEE EVENT EPORT (LER)TEXT CONTINUATION U.S.NUCLEAR REOULATORY COMMISSION APPROVED OMB NO.3(50-0(04 EXPIRES: 8/31/88 FACILITY NAME (I)DOCKET NUMBER (2)YEAR LER NUMBER (6)SEOUENTIAL NUMSER REVISION NUMEER PACE (3)SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 TEXT//Prr>>ro<<>>co lr rodUEa/I/w a////Oo>>///l(C

%%<<3//8/(9/(17)0 5 0 0 0 4 0 0 8 7 0 1-0 0 0 3 OF 0 3 Cause The cause of the first AFW actuation was the"A" MFP trip which was due to a feedwater oscillation.

The oscillation was caused by the feedwater isolation valve reopening following the licensed control operator's two attempts to close it, in accordance with plant procedures.

Due to feedwater system design problems, the MFP discharge valves were in a throttled position to maintain a lower differential pressure across the feedwater regulating valves.The combination of these created a high discharge pressure condition on the MFP, causing it to trip.The root cause of the MFP trip is the system design problems.The second and third AFW actuations, on the"B" MFP trips, were caused by equipment failure.The valve stem on the"B" MFP recirculation valve had separated.

The cause of the valve stem failure was vibration due to the large differential pressure across the valve.~Anal sis These actuations are reportable in accordance with 10CFR50.73(a)(2)(iv) as automatic actuations of an Engineered Safety Feature (Auxiliary Feedwater System).There were no safety consequences as a result of this event;although operation of a safety system was challenged (AFW).The AFW system started as required upon loss of Main Feedwater to maintain water levels in the steam generators.

In all three actuations, the plant was in the process of shutting down, and the loss of Main Feedwater did not result in a plant trip.The AFW start is non-safety and anticipatory.

Had this event occurred under worse conditions (i.e., at 100X power), the loss of the MFP would have resulted in an automatic turbine runback to 50X power with the potential for a reactor trip, due to low steam generator water levels during the transient.

A loss of all Main Feedwater is an analyzed accident in the FSAR.Previous AFW System actuations not associated with reactor trips were reported in LERs 87-026-00, 87-046-00, and 87-047-00.

Corrective Actions The separated stem on the"B" MFP recirculation valve was weld repaired.An orifice will be install.ed on the MFP recirculation lines to provide back pressure on the valve and reduce the differential pressure across the valve.Additional changes to the feedwater system to improve its reliability are being examined.NRC FORM 366A (983)*U.S.OPO:(988.OB2d 538/455 Carolina Power&Light Company HARRIS NUCLEAR PROJECT P.O.Box 165 New Hill, NC 27562 SEI'0 198/File Number'SHF/10-13510C Letter Number.'HO-870504 (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 REPORT 87-051-00 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:skin Enclosure cc.'r.J.Nelson Grace (NRC-RII)Mr.B.Buckley (NRR)Mr.G.Maxwell (NRC-SHNPP)MEM/LER-87-051/1/OS1 E

FUEL fPB BREACH RCS f PB BREACH CONTAINMENT FPB BREACH UPDATE Csf STATUS BOARD BELOW CSF-I SUBCRITICALITY CSF-2 CORE COOLING CSF-3 HEAT SINK CSF-4 INTEGRITY CSF-5 CONTAINMENT 0 0 0 0 0 O~1 0 0 0 0 0 0 0 0 8 0 0--0 0 0 CSF-I YES RED OR MAGENTA NQ CS.-2 RED NQ FUEL JEOPARDY FUEL FPB QK YES CSF 3 RED NQ YES CSF-4 ED QR MAGENTA RCS JEOPARDY NQ RCS FPB l3K csf-s YES RED NQ csf-s.YES MAGENTA NQ CONTAINMENT FPB QK CONTAINMENT JEOPARDY REVIEV ATTACHMENT 3 UPDATE FPB STATUS BOARD BELQV-FUEL FP3 INTACT INTACT RCS FPB CQNTAINTMENT FPB INTACT JEOPARDIZED JEOPARDIZED JEOPARDIZED BREACHED BREACHED BREACHED EAL f LQVPATH REVIEWED NQ 10 YES z 4TVS NQ YES YES GENERAL EMERGENCY NQ (F'RQM FLQVPATH OR ATWS)3 FPBs BREACHED/JEOPARDIZED YES NQ4 YES SITE-EMERGENCY NQ (FROM FLQVPATH QR ATVS)2 FPBs BRE4CHED/JEOPARDIZED YES ALERT (fROM FLQVP4TH OR ATVS)YES 1 FPB BREACHED/JEQP4RDIZED YES NQ EVALUATE 4GAINST UNUSUAL EVENT MATRIX 12 M4NUAL NQ REACTOR TRIP SUCCESSFUL YES ANY UNUSU4L NQ EVENT CONDITION YES FUEL f PB YES BREACHED 13 NQ 4TVS ALERT ATWS SITE EMERGENCY ATVS GENERAL EMERGENCY 4TVS ALERT CONDITION EXISTS GNLY FOR THE PERIOD VAEN RODS ARE UP 4TVS SITE EHERGENCY CONDITION EXISTS IR)LY FOR THE PERIOD VHEH RGGS ARE (P 47VS GDKRAL fJS)RGGHCY CONDITION EXISTS ONLY FOR THE PERIOD VHEN RODS ARE UP DECLARE GENERAL EMERGENCY DECLARE SITE EMERGENCY DECLARE ALERT DECL4RE UNUSUAL EVENT NQ EMERGENCY DECLARATION 14 TIME TIME TIHE TIME TIME UNUSUAL EVEN T MATRIX GASEOUS OR LIQUID EFFLUENT(S)

EXCEEDING TECHNICAL SPECIf'ICATIQHS FUEL DAMAGE INDICATION 1)GROSS f'AILED f'UEL DETECTOR INDICATES AN INCREASE GREATER TH4H 2 X 10 CPH WITHIN 30 MINUTES.2>SPECIFIC ACTIVITY OF THE RE4CTOR COOLANT EXCEEDS THE SHHPP TECHNICAL SPECIF'IC4TIO 3.4.8.f4ILURE TO COHPLY VITH THE SHNPP TECHHICIAL SPECIF ICATIONS INSTAN-TANEOUS LIMITS IN 3.11 FOR G4SEOUS EFFLUEHTS OR F'R LIQUID Eff LUEHTS.LOSS Qf SECONDARY CQQL4NT OR COOLING HA AM VA BREAKS I)IHDIDE COHT4INHEHT, 2)OUTSIDE COHTAIHHEHT OR f'AILURE OF A STEAM GENERATOR SAFETY OR RELIEF VALVE TO RESEAT AFTER OPERATIO)4 OR STEAH GENERATOR BLOVDOVH LINE BREAK.(4PPLICABLE IN MODES L2,63)OR APID DEPRESSURIZATIOH OF SECONDARY SIDE.CONTAINMENT INTEGRITY LOSS OF CON HT INTEGRITY REQUIRING SHUTDOVN BY THE SHHPP TECHNICAL SPECIFICATIONS 3.6.LOSS OF REACTI1R COOLANT I)IN EXCESS OF THE SHHPP TECHNICAL SPECIFICATION 3.4.6, 2)FAILURE Of A PRES" SURIZER SAF'ETY OR RELIEF VALVE TO RESEAT ARTER OPER4TION.

3)PRIMARY TO SECOND4RY SYSTEM LEAK4GE IN EXCESS Of THE SHHPP TECHNICAL SPECIF'IC4TIOH 3.4.6.LOSS OF SHUTDOWN f UNCTIQNS (DECAY HEAT>LOSS F ESF'EQUIRING SHUTDOVN BY THE SHHPP TECHNICAL SPECIFICATIONS (E,G BECAUSE OF MALFUNCTION, PERSONNEL ERROR OR PROCEDURAL INADEQUACY.)

LOSS Of PQVER I)LOSS OF OFFSITE POVER, OR 2)LOSS Of BOTH DIESEL GENERATORS.

LOSS QF CONTROL BOARD 4L*RM, INDICATIONS 4SSESSHENT 4ND CQHHUNICATIQN CAPABILITY 1)LOSS OF INPUTS FROH IHSTRUHEHTATIOH INCLUDED IN THE SHHPP TECHNICAL SPECIF ICATION 3.3'IHSTRUHEHTATION'O AN EXTENT REQUIRING PLANT SHUTDOVH.2)LOSS OF'LL REPRESENTATIVE HETEOROLOGICAL DAT4.3>INABILITY OF'RFIS TO PERFORM ITS INTENDED FUNCTION FOR 4 CONTIN-UOUS PERIOD OF 60 HIHUTES VHILE IN MODES 1,2,3,OR 4 AS DEFINED BYi A.FAILURE OF BOTH CPU'S.B.FAILURE OF BOTH DATA COHCENTRATORS C.FAILURE OF'OTH D4TA DISCS.D.INABILITY TO DISPLAY SPDS IN THE CONTROL ROOM.E INABILITY TO UPDATE CURRENT DAT4 DISPLAYS IN THE CONTROL ROOM.(THIS IS HOT TO BE CONSTRUED AS A f AILURE OF A SINGLE V4RIABLE OR SMALL SUBSET Of DAT4.4)f'AILURE Of'OTH SITE TELEPHONE AHD EHERGEHCY TELEPHONE SWITCHES f IRE SECURITY THREAT FIRE LASTING MORE THAN A SECURITY ALERT HAS 10 HIHUTES WITHIN BEEN DECLARED 43 DEFINED PROTECTED AREAS.IN THE SECURITY PLAN NATURAL PHENOMENA 4ND OTHER PLANT H4ZARDS!)ALARM ON SEISHIC HOHITORS INDICATING EARTHQUAKE.

2)HURRICANE OR TORNADO CROSSING EAB.3)AIRCRAf T CRASH VITHIN EAB OR UNUSUAL 4IRCRAF ACTIVITY OVER f 4CILITY.4>TRAIN DERAILHEHT VITHI I EAB.5)UNPLANNED EXPLOSION VITHIH EAB.'6)UNPLANNED TOXIC OR fLAHM4BLE GAS RELEASE VITHIH CAIL 7)TURBINE ROTATING COMPONENT FAILURE CAUSING R4PID PLANT SHUTDOVH.8)V4TER LEVELS IN THE MAIN AHD 4UXILIARY RESERVOIRS

>2402 f'T.4ND 257.7 f T RESPECTIVELY OR V4TER LEVEL LESS TH4N 205.7FT IN THE M4IH RESERVIOR.

SITE EMERGENCY COORDINATOR JUDGEMENTS OTHER PL4HT CONDITIONS EXIST THAT VARRAHT INCREASED 4VAREHESS ON THE PART OF A PLANT OPERATING STAR'f;CHATHAH, H4RNETT, LEE, AND V4KE COUNTIES AHD THE ST4TE Of NORTH CAROLINA OR REQUIRE PL4HT SHUTDOVH UNDER SHHPP TECHNICAL SPECIFIC4TIOH OR INVOLVE OTHER THAN NORMAL CONTROLLED SHUTDOWN (EAi COOLDOVN RATE EXCEEDING TECHNICAL SPECIFICATION LIMITS, PIPE CR4CKIHG FOUND DURING OPERATION).

ATTACHMENT 1 OTHER EVENTS OR PECIFIC LCQs EXCEEDE 1>UNPLANNED ECCS DISCHARGE TO VESSEL 2)IHITI*TKIN OF'NY PLANT SHUTDOVH REQUIRED BY TECHNICAL SPECIFICATION 3>LOSS OF FIRE PROTECTION SYSTEM f'UNCTION REQUIRING SHUTDOVH BY THE SHHPP TECHNICAL SPECIFICATIOH 3.7.10.4)COHT4HIHATED INJURED INDIVIDUAL REQUIRING OFF SITE HEDIC4L TRE4TMEHT.

17 EMERGENCY ACTION LEVEL NETWORK PEP-101 REV.2 PAGE 9 OF 12 9109&DDGR 7-c i