ML17279A294

LER 87-006-00:on 870426,after Shutdown Margin Demonstration, Reactor Protection Sys Tripped When Last Shorting Link Improperly Installed.Cause Determined to Be design-related. Terminal Strip Arrangement Will Be evaluated.W/870522 Ltr

ML17279A294
Person / Time
Site:	Columbia
Issue date:	05/22/1987
From:	ARBUCKLE J D, POWERS C M WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-87-006, LER-87-6, NUDOCS 8706050352
Download: ML17279A294 (7)

Text

ACCESSION NBR'I, FAC IL: 50-397 Jl i AUTH.NAME ARBUCKLE>J.D POWERS>C.M.REC IP.NAME REQULAT RY NFORMATION DISTR IBUTI 0 SYSTEM (R IDS)87060503 DOC.DATE: 8//05/22 NOTARIZED:

NO DOCKET WPPSS Nuc 1eaT Pro gee t>U>>i t 2>Wash ing ton Pub 1 i c Po>e 05000397 AUTHOR AFFILIATION Washington Public Po<<er Supply System Washington Public Pover Supply System RECIPIENT AFFILIATION

SUBJECT:

LER 87-006-00:

on 870426>a~ter shutdown margin demonstral,ion>

reactor protection sos tripped when last shorting link improperly installed.

Cause de+ermined to be design-related.

Terminal strip arrangement will be evaluated.

W/870522 l+DISTRIBUTION CODE: IE22D COPIES RECEIVEl):

LTR ENCL SIZE: TITLE: 50.73 Licensee Event Report (L1=6)>Incident Rpt>etc.NOTES: RECIPIENT ID CODE/NAl'lE PD5 LA S*MWORTH R INTERNAL: ACRS MICHELSON AEOD/DOA AEOD/DSP/TPAB NRR/DEST/ADE NRR/DEST/CEB NRR/DEST/I CSB NRR/DEST/MTB NRR/DEST/RSB NRR/DLPG/HFB NRR/DOE*/EAB NRR/DREP/RPB NRR/PMAS/PTSB RES DEPY QI EXTERNAL: EQRG GROH>M LPDR NSIC HARRIS J COPIES LTTR ENCL 1 1 1 1 1 f 1 f 1 1 0 1 1 1 1 1 1 2 2 1 1 1 5 5 1 1 1 1 RECIP I ENT ID CODE/NAME PD5 PD ACRS MOELLER ALOD/DSP/ROAB DEnRO NHR/DEST/ADS h!RR/DEST/ELB NHR/DEST/MEB NRR/DEBT/PSB NRR/DEST/SGB NRR/DLPG/GAB h!RR/DREP/RAG A ILRB REG F LE 0 FILE Of H ST LOBBY WARD NRC PDR NSIC MAYS>G COPIES LTTR ENCL 1 2 2 2 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 TOTAL NUMBER OF COPIES REQUIRED: LT1R 42 ENCL 40 NAC form 2$$(042)LtCENSEE EVENT REPORT (LER)US.NUCLEAR AEOULATOAY COENIISSION APPROVEO OMS NO.21$0MIOe EXtlAKS: SISIISS fACILITY NAME (I)DOCXET NUMSEA (2)0 5 0 0 0 1 OF Reactor Protection System Trip During Refueling Operations Due To Improper MONTH OAY YEAR EVENT DATE LS)YEAR LKR NLNNKR (Sl SEQUENTIAL NUMEEA RKtORT DATK ITI NUMEEII MONTH DAY YEAR DOCXET NUMSER($)O'0 0 0 FACI LIT Y NAMES OTHER FACILITIES INVOLVKO (S)DPE RAT(NO MODE (SI~OIEEA LEUK(.(10)20A02(EI 2(L4M4)(1 I I II 20.40$le I (1)(E I 20AOS(~I(1)(EI)20AOS (e)(1)(lel 20AO$4)(I)Iel 20 A($(e)SO M(eHI)SOW(e)(2)$0.224)l2)(l)SO.T$(el(2)(E)$0.224)(2)(SI)LICENSEE CONTACT FOA THIS LKA l12)$0.124)l2)(Ie)$0.224)(2)(r)$0 T$4)(2)(rS)$0.724)(2)(rIE)(Al$0.724II2)(rIEIIS)

SO.TS(e)(2)(e)

THIS AEfORT IS SUSMITTKD PURSUANT TO THE REOUIAKMKNTS OF 10 Cfh (I: ICneeo One Or mOre OI tne IerrerVnFI III)0 5 0 0 0 TATI($)TS.TI (e)OTHER Isoeelrf In Aortreet Oeroreenrtln Test HhC Form JSSAI NAME J.D.Arbuckle, Compliance Engineer TELEtHONE NUMSER AREA CODE 50 93 77-211 5 COMPLETE ONK LINK fOA EACH COMfONENT FAILURE DESCAISED IN THIS REPORT (12)SYSTEM COMtONENT MANUf AC.TUAKR:N~N@EPORTASLE:V"...'AUSE SY$TEM COMPONENT TO NPRDS MANUFAC.TURER EPORTASL TO NPRDS 3@.')i.r,&~4 5~4'.SUtf(.KMENTAL REPORT EXPECTED i(el EXPECTED SUSMI$SION DATE (1$)MONTH OAY YEAR YES III Per, eomfrete f Xtf CTf 0 SIISMISSIDH DATE)NO ASST AACT ILImlt to IeOO eoeeee, I e., eorrrozlmetely Iilteen vnpreeneee typewrrtten llneel IIE)On April 26, 1987 at 1933 hours0.0224 days <br />0.537 hours <br />0.0032 weeks <br />7.355065e-4 months <br />, following a shutdown margin demonstration surveillance, a Reactor Protection System (RPS)trip occurred while the last shorting link was being installed.

The link for RPS subchannel B2 was inadvertently placed at the wrong terminal hoard points.This caused an electrical short in the manual scram circuit which tied two power supplies together.As a result, two manual scram circuit fuses blew, which caused a reactor scram.Since the reactor was shutdown prior to the event, no actual control rod movement occurred as a result of the scram.The two manual scram circuit fuses were replaced, the shorting link was installed properly and the system was restored to normal shutdown status.The root cause of this event has heen determined to be design-related in that the physical arrangement of the terminal strip in the Control Room cabinet makes it difficult to irista11 the shorting links to the rear side of the terminal strip.An Engineering evaluation will be performed to consider changing this arrangement.

NRC form$$$(042)870b050352 870522 PDR ADOGK 0500032)7 S PDR

~0 l NRC Form 3SSA (943 I LlCENSEE EVENT REPORT (LER)TEXT CONTlNUATION U.S.NUCLEAR REGULATORY COMMISSION APPROVEO OMS NO.3150&/OS EXP IR ES: 8/31/85 FACILITY NAME III Washington Nuclear Plant-Unit 2 TEXT/I/moro sPoro/I roqoSor/.vso~HiIC Form 3/EIAS/IITI OOCKET NUMSER Ill o s 0 0 0 3 9 7 VSAA 8 7 LER NUMSER ISI SSOVSNI'IAL NVM SII 0 0 6 Ir s v IS IO N NVMSSR 0 0 2 PACE I31 OF 0 3 Plant Conditions a)Power Level-O'A b)Plant Mode-5 (Refuelinq)

Event Description On April 26, 1987 at 1933 hours0.0224 days <br />0.537 hours <br />0.0032 weeks <br />7.355065e-4 months <br />, following a shutdown margin demonstration surveillance, a Reactor Protection System (RPS)trip occurred while the last shorting link was being installed (shorting links had already been properly installed in Divisions Al, Bl, and A2).The link for RPS subchannel 82 was inadvertently placed at the wrong terminal board points (AA-70 and AA-71 instead of AA-6q and AA-70).This caused an electrical short in the manual scram circuit which tied two power supplies together.As a result, manual scram circuit fuses C72-F15C and C72-F15D blew.Loss of power to both RPS Division Manual Trip Relays resulted in a reactor scram.Since the reactor was shutdown prior to the event, no actual control rod movement occurred as a result of the scram.The root cause of this event has been determined to be design-related in that the physical arrangement of the terminal strip in the Control Room cabinet makes it difficult to install the shortinq links to the rear side of the terminal strip.This is particularly true of Control Room panel P611D where an existing wire is already landed at the rear side terminal, bottom screw.Immediate Corrective Action The two manual scram circuit fuses were replaced, the shorting link was installed properly and the system was restored to normal shutdown status.Further Corrective Action~The affected RPS circuitry will be checked, during routine surveillance testing, for possible damage prior to the next plant startup.~An Engineering evaluation will be performed to consider changing the physical arrangement of the terminal strips to allow easier installation of the shorting links.Safety Significance There is no safety significance associated with this event in that the reactor was in cold shutdown prior to the event, there was no actual initiating condition and the RPS functioned as designed to cause a reactor scram.This event caused no threat to the safety of the public or plant personnel.

NIIC FORM SSSA/9')

NRC Form 354A (843)LICENSEE EVENT REPORT ILERI TEXT CONTINUATION US.NUCLEAR REOULATORY COMMISSION APPROVEO OMS NO.3150M)(N EXPIRES: 8/31/85 FACILITY NAME (11 DOCKET NUMSER 12)LER NUMSER (5)PACE (3)"EAII M ttOURNTIAL NUM t II Ilt V I5 IO N NVMttII Washington Nuclear P1ant-Vnit 2 TEXT IJf mcw epecre 4 IpyeirNf, IIM arftfrmefl HEMIC%%dnII 355A3)(17)0 5 0 0 0 0 6 0 oF0 3 Simi1ar Events LER 86-006 E IIS Information Text Reference EIIS Refer ence System Component Reactor Protection System JC NIIC FORM 3dtA (84)3)

WASHINGTON PUBLIC POKER SUPPLY SYSTEM P.O.Box 968~3000 George Washington Way~Richland, Washington 99352 Docket No.50-397 May 22, 1987 Document Control Desk U.S.Nuclear Regulatory Commission Washington, D.C.?0555

Subject:

NUCLEAR PLANT NO.2 LICENSEE EVENT REPORT NO.87-006

Dear Sir:

Transmitted herewith is Licensee Event Report No.87-006 for WNP-2 Plant.This report is submitted in response to the report requirements of 10CFR50.73 and discusses the item of reportability, corrective action taken, and action taken to preclude recurr ence.Very truly yours, 6's"t4=C.M.Powers (M/0 927M)WNP-2 Plant Manager CMP: 1 c

Enclosure:

Licensee Event Report No.87-006 cc: Mr.John B.Martin, NRC-Region V Mr.R.T.Dodds, NRC-Site (901A)Mr.M.E.Milbrot, BPA (M/D 399)INPO Records Center-Atlanta, GA Ms.Dottie Sherman, ANI Mr.C.E.Revell, BPA (M/D 399)re I