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, Watson R 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 DOCKET FACIL: 50-400 Shearon Harris, Nuclear Power Plant> Unit 1> Carolina 05000400 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

SUBJECT:

LER 87-051-00: on 870831> main feedwater pump A tripped due ta 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 TITLE: 50 73 Licensee Event Report (LER)> Incident Rpt>

+ ENCL /'IZE:

etc..

NOTES: Application for permit renewal filed. 05000400 RECIPIENT COPIES REC IP IENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-1 LA 1 1 PD2-1 PD 1 1 BUCKLEY, B 1 INTERNAL: ACRS MICHE! SQN 1 ACRS MOELLER 2 2 AEOD/DQA 1 1 AEOD/DSP/NAS 1 1 AEQD/DSP/ROAB 2 AEOD/DSP/TPAB 1 1 1 1 NRR/DEBT/ADS 0 DEDRQ'RR/DEST/CEB 1 1 NRR/DEST/ELB 1 1 I

NR R /DEST/ C SB 1 1 NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 NRR/DEST/SQB 1 1 NRR/DLPG/HFB 1 1 NRR/DLPG/GAB 1 NRR/DQEA/EAB 1 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2 /SIB 1 1 NRR/PMAS/ILRB 1 1 REQ 02 1 1 RES DEPY GI 1 1 RES TELFORD> J 1 1 RES/DE/EIB 1 RQN2 FILE 01 1 1 EXTERNAL: EGS.Q GRQH, M H ST LOBBY WARD 1 1 LPDR NRC PDR 1 1 NSIC HARRIS> J NSIC NAYS> G 1 1 TOTAL NUMBER OF COP IES REQUIRED: LTTR 44 ENCL 43

NRC Form 38$ U.S. NUCLEAR REOULATORY COMMISSION

'0;83)

APPROVED OMB NO. 31504)104 EXPIRES: 8/31/88 LICENSEE EVENT REPORT {LER)

FACILITY NAME (Il DOCKET NUMBER (2) PA E 3 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 0 5 0 p p4 00 FEEDWATER SYSTEM ACTUATIONS ON MAIN FEEDWATER PUMP TRIPS DUE TO 1OFO'UXILIARY DESIGN AND E UIPMENT FAILURE EVENT DATE ISI LER NUMBER (8) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR SFOUSNTIAI. 'rgb REVISION MONTH DAY YEAR FACILITYNAMES DOCKET NUMBER(S) r NUMBER NUMBER 0 5 0 0 0 31 87 8 7 0 5 1 0 0 9 3 0 8 7 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T0 THE REOUIREMENTS OF 10 CF R ()l /Check one or more of the IOIlovfinP) (11 OPERATINO MODE (8) 20A02(B) 20.40S(cl X 50.73(e)(2)(ivl 73.71(B)

POWE R 20A05( ~ l (1)(B 50.38(cll1) 50,73(e)(2)(v) 73.71(c)

LEYEL 0 0 20.405(e) (1 l(ii) 50.38(cl(2) 50.73(e) (2)(vip OTHER (Specify in At)street below enrf In Test, IVRC Form 20.405( ~ Ill((i)i) 50.73(e) l2)(0 50,73(e l(2) ( v) it) (Al 366A/

20A05( ~ ) (1) (Iv) 50.73(el(2l(ill 50.73(e) (2) (viii)(Bl 20.405(e) (I l(v) 50.73(e l(2) (Iii) 50.73( ~ )(2)(x)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE

0. N. HUDSON, SENIOR ENGINEER REGULATORY COMPLIANCE 919 362 -2 63 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

MANUFAC- REPORTABLE .B)S 1 MANUFAC. EPORTAB LE CAUSE SYS'EM COMPONENT TO NPRDS CAUSE SYSTEM COMPONENT TURER TURER TO NPRDS

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R .. ~,V,'I X S J FC VM 120 Y

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. (l?o&~?:ia ) o Ni SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SU 8 M I SS ION DATE (15)

YES (If yes, complete EXPECTED SIIShtISSIDII DATE) NO ABSTRACT ILlmlt to f400 specer, Ie., epproeimetely fifteen slnpre spree typetnritten Ilnesl (18)

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 U.S. NUCLEAR REGULATORY COMMISSION (94)3)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3150-0104 EXPIRES: 8/31/BB FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (5) PAGE (3)

SEQUENTIAL REv/BICN SHEARON HARRIS NUCLEAR POWER PLANT YEAR NUMBER NUMBER UNIT 1 0 5 0 0 0 4 0 8 7. 0 5 1 0 0 0 2 OF 0 TEXT/K/rrcro<<>>ce/my/rr/ror/ r>>o r/8/or>>/NRC Forrn38549/(IT)

Descri tion of Events 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 *U.S.GPO;1988 0 824 538/455 (943)

NRC Form 366A U.S. NUCLEAR REOULATORY COMMISSION (943)

LICENSEE EVENT EPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3(50-0(04 EXPIRES: 8/31/88 FACILITY NAME (I) DOCKET NUMBER (2) LER NUMBER (6) PACE (3)

YEAR SEOUENTIAL REVISION NUMSER NUMEER SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 0 5 0 0 0 4 0 0 8 7 0 10 0 0 3 OF 0 3 TEXT //Prr>>ro <<>>co lr rodUEa/ I/w a////Oo>>///l(C %%<< 3//8/(9/ (17)

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 *U.S.OPO:(988.OB2d 538/455 (983)

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 UPDATE Csf FUEL RCS CONTAINMENT STATUS BOARD fPB BREACH f PB BREACH FPB BREACH BELOW CSF-I CSF-2 CSF-3 CSF-4 CSF -5 CONTAINMENT SUBCRITICALITY CORE COOLING HEAT SINK INTEGRITY 0 0 0 0 0 0 O ~1 0 0 0 0 0 0 8 0 0 0 0 0 0 CSF -I YES RED OR MAGENTA NQ CS.-2 RED FUEL JEOPARDY NQ 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 CONTAINMENT JEOPARDY NQ CONTAINMENT FPB QK REVIEV ATTACHMENT 3 UPDATE FPB STATUS BOARD BELQV FUEL RCS CQNTAINTMENT FP3 FPB FPB INTACT INTACT INTACT JEOPARDIZED JEOPARDIZED JEOPARDIZED BREACHED BREACHED BREACHED 10 EAL NQ f LQVPATH REVIEWED YES z

GENERAL SITE 2 FPBs ALERT 1 FPB NQ NQ 3 FPBs NQ4 - EMERGENCY NQ EMERGENCY BREACHED/ BRE4CHED/ (fROM FLQVP4TH BREACHED/

(F'RQM FLQVPATH (FROM FLQVPATH JEOPARDIZED OR ATVS) JEQP4RDIZED JEOPARDIZED ATVS)

OR ATWS) QR NQ 4TVS YES YES YES EVALUATE 4GAINST YES YES YES UNUSUAL EVENT MATRIX YES 12 ANY UNUSU4L NQ EVENT CONDITION M4NUAL NQ REACTOR TRIP SUCCESSFUL YES YES FUEL f PB YES 13 BREACHED NQ 4TVS ALERT ATWS ATVS SITE EMERGENCY GENERAL EMERGENCY DECLARE DECLARE DECL4RE NQ DECLARE EMERGENCY SITE ALERT UNUSUAL 4TVS SITE EHERGENCY 47VS GDKRAL fJS)RGGHCY GENERAL DECLARATION 4TVS ALERT EMERGENCY EVENT CONDITION EXISTS GNLY FOR CONDITION EXISTS IR)LY FOR CONDITION EXISTS ONLY FOR EMERGENCY THE PERIOD VAEN RODS ARE UP THE PERIOD VHEH RGGS ARE (P THE PERIOD VHEN RODS ARE UP 14 TIME TIHE TIME TIME TIME UNUSUAL EVEN T MATRIX LOSS QF CONTROL BOARD SITE EMERGENCY NATURAL PHENOMENA GASEOUS OR LIQUID LOSS OF 4L*RM, INDICATIONS f IRE SECURITY THREAT COORDINATOR OTHER EVENTS OR LOSS Qf SECONDARY CONTAINMENT LOSS OF LOSS Of PQVER 4ND OTHER EFFLUENT(S) EXCEEDING FUEL DAMAGE INDICATION INTEGRITY REACTI1R COOLANT SHUTDOWN f UNCTIQNS 4SSESSHENT 4ND PLANT H4ZARDS JUDGEMENTS PECIFIC LCQs EXCEEDE CQQL4NT OR COOLING (DECAY HEAT> CQHHUNICATIQN CAPABILITY TECHNICAL SPECIf'ICATIQHS UNPLANNED ECCS I) IN EXCESS OF THE SHHPP LOSS F ESF'EQUIRING I) LOSS OF OFFSITE FIRE LASTING MORE THAN A SECURITY ALERT HAS  !) ALARM ON SEISHIC OTHER PL4HT CONDITIONS 1>

HA AM VA LOSS OF CON HT 1) LOSS OF INPUTS FROH BEEN DECLARED 43 DEFINED HOHITORS INDICATING EXIST THAT VARRAHT DISCHARGE TO VESSEL f4ILURE TO COHPLY VITH 1) GROSS f'AILED f'UEL TECHNICAL SPECIFICATION SHUTDOVN BY THE SHHPP POVER, OR 10 HIHUTES WITHIN DETECTOR INDICATES AN BREAKS INTEGRITY REQUIRING

2) LOSS Of BOTH DIESEL IHSTRUHEHTATIOH INCLUDED PROTECTED AREAS. IN THE SECURITY PLAN EARTHQUAKE. INCREASED 4VAREHESS ON 2) IHITI*TKINOF'NY PLANT THE SHNPP TECHHICIAL I) IHDIDE COHT4INHEHT, SHUTDOVN BY THE SHHPP 3.4.6, TECHNICAL SPECIFICATIONS SHUTDOVH REQUIRED BY INCREASE GREATER TH4H IN THE SHHPP TECHNICAL 2) HURRICANE OR TORNADO THE PART OF A PLANT SPECIF ICATIONS INSTAN- 2) OUTSIDE COHTAIHHEHT TECHNICAL SPECIFICATIONS 2) FAILURE Of A PRES" (E,G BECAUSE OF GENERATORS.

SPECIF ICATION 3.3 OPERATING STAR'f;CHATHAH, TECHNICAL SPECIFICATION 2 X 10 CPH WITHIN 30 MALFUNCTION, PERSONNEL CROSSING EAB.

TANEOUS LIMITS IN 3.11 3.6. SURIZER SAF'ETY OR 'IHSTRUHEHTATION'O 3> LOSS OF FIRE OR AN 3) AIRCRAf T CRASH VITHIN H4RNETT, LEE, AND V4KE FOR G4SEOUS EFFLUEHTS OR MINUTES. f'AILURE OF A STEAM RELIEF VALVE TO RESEAT ERROR OR PROCEDURAL EXTENT REQUIRING PLANT COUNTIES AHD THE ST4TE PROTECTION SYSTEM F'R LIQUID Eff LUEHTS. ACTIVITY INADEQUACY.) EAB OR UNUSUAL 4IRCRAF 2> SPECIFIC OF GENERATOR SAFETY OR ARTER OPER4TION. f'UNCTION REQUIRING SHUTDOVH. ACTIVITY OVER f 4CILITY. Of NORTH CAROLINA OR THE RE4CTOR COOLANT RELIEF VALVE TO RESEAT 3) PRIMARY TO SECOND4RY

2) LOSS OF'LL 4> TRAIN DERAILHEHT VITHI REQUIRE PL4HT SHUTDOVH SHUTDOVH BY THE EXCEEDS THE SHHPP AFTER OPERATIO)4 OR SYSTEM LEAK4GE IN REPRESENTATIVE EAB. UNDER SHHPP TECHNICAL SHHPP TECHNICAL TECHNICAL SPECIF'IC4TIO STEAH GENERATOR EXCESS Of THE SHHPP SPECIFIC4TIOH OR INVOLVE SPECIFICATIOH HETEOROLOGICAL DAT4. 5) UNPLANNED EXPLOSION 3.4.8. BLOVDOVH LINE BREAK. TECHNICAL SPECIF'IC4TIOH 3.7.10.

3.4.6. 3> INABILITY OF'RFIS TO I VITHIH EAB. OTHER THAN NORMAL (4PPLICABLE IN MODES PERFORM ITS INTENDED '6) UNPLANNED TOXIC OR CONTROLLED SHUTDOWN 4) COHT4HIHATED INJURED L2,63) FUNCTION FOR 4 CONTIN- fLAHM4BLE GAS RELEASE (EAi COOLDOVN RATE INDIVIDUAL REQUIRING OR VITHIH CAIL EXCEEDING TECHNICAL OFF SITE HEDIC4L UOUS PERIOD OF 60 APID DEPRESSURIZATIOH OF HIHUTES VHILE IN MODES 7) TURBINE ROTATING SPECIFICATION LIMITS, TRE4TMEHT.

SECONDARY SIDE. 1,2,3,OR 4 AS DEFINED BYi COMPONENT FAILURE PIPE CR4CKIHG FOUND A. FAILURE OF BOTH CPU'S. CAUSING R4PID PLANT DURING OPERATION).

B. FAILURE OF BOTH DATA SHUTDOVH.

COHCENTRATORS 8) V4TER LEVELS IN THE C. FAILURE OF'OTH D4TA MAIN AHD 4UXILIARY DISCS. RESERVOIRS > 2402 f'T.

D. INABILITY TO DISPLAY 4ND 257.7 f T SPDS IN THE CONTROL RESPECTIVELY OR V4TER ROOM. LEVEL LESS TH4N 205.7FT E INABILITY TO UPDATE IN THE M4IH RESERVIOR.

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. 17

4) f'AILURE Of'OTH SITE TELEPHONE AHD EHERGEHCY TELEPHONE SWITCHES ATTACHMENT 1 EMERGENCY ACTION LEVEL NETWORK PEP 101 REV. 2 PAGE 9 OF 12 9109&DDGR 7-c i