ML18022A504

LER 87-018-00:on 870403,manual Reactor Trip Initiated Due to Loss of Both Main Feedwater Pumps.Caused by Inadvertent Short of Test Leads in Process Instrumentation Cabinet & Incorrect Setpoint.Undocumented Leads removed.W/870430 Ltr

ML18022A504
Person / Time
Site:	Harris
Issue date:	04/30/1987
From:	HOWE A, WATSON R A CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-870412-(O), LER-87-018, LER-87-18, NUDOCS 8705060271
Download: ML18022A504 (5)

Text

REQUL Y INFORMATION DIBTRIBUTI SYSTEM<R IDS)i ACCESSION NBR: 87050b0271 DOC.DATE: 87/04/30 NOTARIZED:

NO FACIL: 50-400 Shearon Harris Nuclear Pover Plant>Unit 1P Carolina AUTH.NAME AUTHOR AFFILIATION HOWE'.Carolina Power 8c Light Co.WATSON>R.A.Carol ina Poller 8(Light Co.RECIP.NAME-RECIPIENT AFFILIATION DOCKET¹05000400 SUB JECT: LER 87-018-00:

on 870403>manual reactor trip initiated due to loss of both main feedeater pumps.Caused bg inadvertent short of test leads in process instrumentation cabi,net 0 incorrect setpoint.Undocumented leads removed.W/870430 ltr.DISTRIBUTION CODE: IE22D COPIEB RECEIVED: LTR g ENCL Q SIZE: TITLE: 50.73 Licensee Event Report (LER)i Incident Rpti etc.NOTES: Application for permit reneual filed.05000400 RECIPIENT ID CODE/NAME PD2-1 LA BUCKLEY B INTERNAL: ACRS MICHELBON AEOD/DOA AEOD/DSP/TPAB NRR/DEST/ADS NRR/DEST/ELB NRR/DEST/MEB NRR/DEBT/PSB NRR/DEST/SQB NRR/DLPG/GAB NRR/DREP/EPB NRR/DREP/RPB NRR/PMAS/PTSB RES SPEIS T EXTERNAL: EQhQ QROH, M LPDR NSI C HARR IS>J COPIES LTTR ENCL 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1~1 1 2 2 1 1 1 1 5 5 1 1 1 REC IP I ENT ID CODE/NAME PD2-1 PD ACRS MOELLER AFOD/DSP/ROAB NRR/DEST/*DE NRR/DEST/CEB NRR/DEST/I CSB NRR/DEST/MTB NRR/DEST/RSB NRR/DLPG/HFB NRR/DOEA/EAB NRR/DREP/RAB RB REQ FILE 02 FILE 01 H BT LOBBY WARD NRC PDR NSIC MAYSi Q COP IEB LTTR ENCL 1 1 2 2 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTlR 41 ENCL 39 NRC Form 388 (943)LICENSEE EVENT REPORT (LER)U.S, NUCLEAA REOULATORY COMMISSION APPAOVED OMB NO.3150010k EXPIAESI 8/31/88 FACILITY NAME (I)Shearon Harris Plant-Unit 1 TITLE (8)Reactor Trip-Loss of Feedwater DOCKET NUMBER (2)0 5 0 0 0 PACE 3 1 OF MONTH DAY YEAR EVENT DATE (5)YEAR LFR NUMBER (5)SSOVENTIAL re)NUMBER S..I REVISION NVMSSR MONTH DAY YEAR REPORT DATE IT)DOCKET NUMBER(S)0 5 0 0 0 FACILITY NAMES OTHER FACILITIES INVOLVED (8)04 03 8 7 OPERATINO MODE (8)1 POWER LEVEL Ci~k@&E'7 0 1 8 0 0 50,73(e)(2)llr)50.73(e)(2)(r)THIS REPORT IS SUBMITTED PURSUANT 7 20A02(8)20AOS(e)(1)(O 20AOS(el(1)

(4)20AOS(e)(l)(IB) 20AOB(e)l1)(lv) 20AOS(e))1)lrl 20AOS(cl SOM(c)(I)50.38(c)(2)50.73(~l(2)ll)50.73(el(2)(ll) 50.73(e l(2)(ill)50.73(el(2)(rill 50.73(el(2)(rill)(A)50.73(e)l2)(vill)(B) 50.73(~)(2)(x I I.ICENSEE CONTACT FOR THIS LER (12I 0 THE REOUIREMENTS OF 10 CFR (): ICneck one or more of the follorflnpl l11 73,71(8)73.71(cl 0 5 0 0 0 OTHER ISpeclfy In Abnrert INIow end ln Text, IVIIC Form 3SSAI NAME Andrew Howe-Re ulator Cpm 1 TELEPHONE NUMBER AREA CODE 919 362 27 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS AEPOAT (13)CAUSE SYSTEM COMPONENT MANUFAC-TURER REPORTABLE TO NPRDS Hp'I CAUSE".C:)'x SYSTEM COMPONENT MANUFAC.TURER EPORTABLE TO NPRDS SUPPLEMENTAL REPORT EXPECTED (18)YES Ilf yer, complete EXPECTED SUBSIISSION OATEI NO ABsTAAcT (Limit ro IcoO rpeceL l.e., epproxlmetely fifteen tlnple.tpece typewritten linn/(15)EXPECTED SU 5 M I SS ION DATE I'IS)MONTH DAY YEAR At 1126 on April 3, 1987, with the plant operating at 75K thermal power level and 560 MWe, a manual turbine trip and subsequent reactor trip was initiated.

The trip was required due to a loss of both main feedwater pumps and the subsequent decrease in steam generator levels.The motor driven auxiliary feedwater pumps started automatically as required upon loss of both main feedwater pumps.Subsequent to the trip the main steamline isolation valves were manually closed to limit the cooldown transient on the Reactor Coolant System (RCS).The plant was stabilized in Mode 3 at the'zero-load RCS Tavg of 557'F.87050b027i 870430 PDR (E)DOCK 05000400 S PDR 5 GRZ l~NRC Form 388 NRC Fotm 366A (94)3)LICENSEE EVENT REPORT{LER)TEXT CONTINUATION U.S.NUCLEAR REGULATORY COMMISSION APPROVED OMB NO.3150&104 EXPIRES: 8/3)/(8 FACILITY NAME (1)OOCKET NUMBER (2)LER NUMBER (6)YEAR i%A SEQUENTIAL

?4 REVISION NUMBER':?A NUMBER PAGE (3)Shearon Harris Plant-'TEXT///mFm 4/>>ce/4/Eqv/FF/

1>>4/I/EEV>>/HRC F4mI 3884'4/(17)0 5 0 0 0 018 0 0 02 DESCRIPTION On April 3, 1987, the plant was operating at approximately 75X thermal power level and 560 MWe.Plant conditions were being maintained in steady state following a reactor startup on April 1 (Reference LER-87-017-0) to allow stabilization of Xenon in the core in preparation for further power ascension testing.At approximately 1123, a low flow annunciator for condensate booster pump 1B alarmed, and at 1125 condensate booster pump 1B tripped, followed by main feedwater pump 1B.Automatic turbine runback to 50X power did not automatically occur as expected, and the operators manually reduced turbine load.At 1126, both heater drain pumps tripped, and before turbine load could be reduced significantly, the second main feedwater pump tripped.,Both motor-driven auxiliary feedwater pumps automatically started due to trip of both main feedwater pumps.Since feedwater could not be immediately restored, a manual trip was initiated.

The manual turbine trip was initiated prior to a manual reactor trip, so the reactor trip occurred due to the turbine trip with reactor power above the P-7 interlock setpoint of 10X power.Subsequent to the trip, the plant was stabilized in Mode 3 at the zero-load RCS Tavg of 557'F with the main steamline isolation valves manually closed to limit the initial cooldown transient.

The cause of the trip was investigated and resolved, and the plant was returned to service on April 4, 1987.CAUSE The initiating event was the trip of condensate booster pump 1B due to a low flow trip caused when test leads connected into the flow instrumentation card in the process instrumentation cabinet (PIC)were inadvertently shorted together.These test leads were being used to provide additional data for evaluating main feedwater and condensate pump trips (Refer'ence LERs 87-008-0, 87-013-0, 87-017-0).

A decision had been made by plant management to connect a personal computer to various condensate and feedwater instrumentation points.During installation, it was determined that additional isolation resistors were necessary between the computer and the plant instrumentation loops.The leads were to be removed from the PIC for the installation of these resistors; however, for one lead, this was not done.As a result, when the resistors were being soldered into the circuit where the lead had not been removed, the circuit was grounded or shorted, causing a low flow annunciator and trip of the condensate booster pump.The PIC where the test leads were installed was physically separated from the area where the isolation resistors were being installed.

The technician working on the isolation resistors could not view the connected test leads and in fact thought all test leads had been disconnected.

'NRC FORM 366A (943)+U.S.GPO;1988.0.824 538/455 NRC Form 368A (983)LICENSEE EVENT REPORT (LER)TEXT CONTINUATION U.S.NUCLEAR REOULATORY COMMISSION APPROVEO OMB NO, 3150M(OS EXPIRES: 8/31/88 FACILITY NAME (1)DOCKET NUMBER (2)YEAR LER NUMBER (6)gag SEQUENTIAL 4%m NUMBER~+: REVISION NUMBER PACE (3)Shearon Harris Plant-Unit 1 TEXT///morB B/roce/B r/U/IBI/Uw B//dOIN/NRC Form 3////AB/(I 2)0 5 0 0 0 P 0 0 1 8 0 0 OF.CAUSE (continued)

The cause of the second main feedwater pump trip is attributed to low suction pressure due to high feedwater flow while operators were attempting to reduce the turbine load and adjust steam generator levels manually.The heater drain pump trips were likely caused by the transient created by the condensate booster pump trip.The test leads had been connected and disconnected in an informal manner without appropriate documentation.

As a result there was no inventory against which to check that all leads had been disconnected prior to starting work on the isolation resistors.

Other test leads were connected to the PICs for approved and ongoing tests although not actively in use at the time..The failure of the turbine runback feature to reduce load to'50X upon trip of one main feedwater pump was due to an incorrect setpoint for a turbine first stage pressure permissive.

The pressure setting specified by design was too high to allow the runback to function for this event.CORRECTIVE ACTION Temporary leads which are not documented by an approved procedure were removed from the PICs, and the cabinets were inspected to verify this condition.

Additionally, test leads installed by approved procedures which were not in active use were also removed.Future installation of temporary monitoring equipment will only be in accordance with approved procedures, and such installations will include an independent verification, as appropriate.

Additionally, test leads will only be connected when required for test and removed after test completion.

NRC FORM 366A (94)3)*U.S.GPO;1988 0.824 538/455 Carolina Power 8 Light Cornpant HARRIS NUCLEAR PROJECT P.O.Box 165 New Hill, NC 27562 APR 3 0]gg7 File Number'SHF/10-13510C Letter Number.'HO-870412 (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 87-018-00 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, RAW:bjb Enclosure R.A.Watson Vice President Harris Nuclear Project cc.'Dr.J.Nelson Grace (NRC-RII)Mr.B.Buckley (NRC)Mr.G.Maxwell (NRC-SHNPP)MEM/HO-8704120/Page 1/OS1