ML17279A348

LER 87-010-00:on 870512,ESF Actuations Occurred.Caused by Inadequate Plant Procedure.Plant Operators Restarted Reactor Protection Sys Motor Generator a & Returned RHR Shutdown Cooling & RWCU Sys to Operation within 1/2 h.W/870611 Ltr

ML17279A348
Person / Time
Site:	Columbia
Issue date:	06/11/1987
From:	Powers C, Washington S WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-87-010, LER-87-10, NUDOCS 8706190065
Download: ML17279A348 (7)

Text

REG T 'NFORNATION DISTR I HU ON YSTEN (R IDB >

ACCESSION NHR 8706190065 DOC. DATE: 87/06/li NOTARIZED: NQ DOCKET N FAG IL: 50-397 MPPSB Nuclear Prospect> Unit 2, Washington Public Powe 05000397

~i JTH. NANE AUTHOR AFFILIATION WASHINGTON> S L. Washington Public Power Supply System POWERS> C. N. Washington Public Power Supply System RECIP. NANE RECIPIENT AFFILIATION

SUBJECT:

LER 87-010-00: on 870512> ESF actuations occurred. Caused bg inadequate plant proceduT e. Plant operators restarted Reactor Protection Sgs Notor Generator A 8. returned RHR shutdown cooling 4 RWCU sos to operation within 1/2 h. W/870611 ltr.

DISTRIBUTION CODE: IE22D COPIEB RECEIVED: LTR TITLE: 50. 73 Licensee Event Repor t (LER)>

J Incident ENCL Rpt>

J etc.SIZE:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAI'IE LTTR ENCL ID CODE/NANE LTTR ENCL PD5 L* 1 1 PD5 PD 3 SANMORTH> R 1 INTERNAL: ACRS NICHELBON ACRS NOELLER 2 AEQD/DQA AEOD/DBP/RQAB 2 2 AEOD/DBP/TPAB 1 DEDRO NRR/DEBT/ADE 0 NRR/DEBT/ADB 0 NRR/DEBT/CEB 1 1 NRR/DEST/ELB 1 NRR /DEBT/ I CBH 1 1 NRR/DEST/NEB 1 NRR/DEBT/NTB 1 1 NRR/DEST/PBH 1 1 NRR/DEBT/RSH NRR/DEST/BGH 1 NRR/DLPG/HFB 1 NRR/DLPG/GAH 1 1 NRR/DOE*/EAB 1 NRR/DREP/RAH 1 1 NRR/DREP/RPB 2 B/ILRH NRR/PNAS/PTSH REG F L 02 1, RES DEPY GI 1 1 E Ol 1 EXTERNAL: EGGING GROH> N 5 5 H BT LOBBY WARD 1 LPDR NRC PDR NBIC HARRIS> J 1 NSIC NAYS> G 1 ~

TOTAL NUNBER QF COPIES REQUIRED: LTTR 42 ENCL 40

NRC Form $ 45 UA. NUCLEAR REQULATORY COANIISSION

$ 43) APPROVED OMS NO. $ 150M104 EXPIRKS: SISIISS LICENSEE EVENT REPORT(LER)

FACILITY NAME Hl DOCXET NUMSER l2)

Washin ton Nuclear TITLE lel Plant - Unit 2 050003971OF03 Emer enc Safety Feature Actuations Caused By Procedure Error EVENT DATE(bl Lbh NUMSKR (Sl REPORTDATK(1) OTHKh FACILITIES INVOLVED0)l MONTH OAY YEAR YEAR SKOVSraTIAI, ?r"a OAY YEAR FACILITYH*MKS DOCKET HUMbER(S) jQ4,. H VM44 rl HVM44rl MONTH 0 5 0 0 0 051 2 8 8 7 0 1 0 0 00 11 7 0 5 0 0 0 TH)s REPDRT ls EUSMITTED PURKUANT To THE le) REDUlhEMKNTS oF 10 cFh (I: Icecap one or more oI toe Iollorrlncl ill)

OPS hATINO MOOS (4) 20A02(4) lb.1$ 4)(2)(H) TX11 Dr) 20AOS(el

~ OWER 2(L4N4)(I)(0 SOM(e)(I) 50.1$ 4)(2)lrl T$ 21(el LEYEL 0 0 20AN4)(IHS) SOM(e)(2) 50.1241(2) (rQ) OTHE R /SpecIIy In Abrtroct ovow enaI In Tart, HIIC Form 20AN(e) I'l(N) 50.1$ 4)(2)(l) 50.1$ 4)(2)(rbhlAI JSSAI 20.405 le) llI (h) 50.1 2 (2)(4 I 50.1$ 4)(2) (rb)) ( ~ )

20AOS 4) (1) lal 50.1 24) (2) lilll 50.1$ (el(2)(nl LICENSEE CONTACT FOR THIS LKR l12)

NAME TELEPHONE NUMSER AREA CODE Steven L. Washin ton Com liance Engineer 50 93 7-COMPLETE ONE LINE FOR EACH COMPONENT FAILURE OKSCRISKO IN THIS REPORT l1$ )

MAHUFAC. EPORTAbLE MAHUFAC.

CAUSE SYSTEM COMPONKNT TURKR TO HPRDS

%MR) x CAUSE COMPONENT TURER KPORTASL TO HPRDS ab MM SUPPLEMENTAL REPORT EXPECTED (Iel EXPECTED MONTH kN&4 DAY YEAR SUE MISSION OATK lid)

YES (II yer, ccrnpNte EXPECTED SUSMISSIOH DATE) HO ASSTRACT ILlmlt to 1400 apecor, I.eeppron)nNtery ltheen Vnoleepece typenrtttrn lineal (14)

On May 12, 1987 WNP-2 was shutdown with the reactor cavity flooded and in the Refueling mode of operation. At 1237 hours0.0143 days <br />0.344 hours <br />0.00205 weeks <br />4.706785e-4 months <br />, a Plant electrician while calibrating the Plant Oscillograph, inadverently caused the loss of offsite power supply (TRS). Plant emergency bus SM-7, which was being supplied hy TRS, automatically switched to the alternate offsite power supply (TRB); however, the momentary loss of power caused the Reactor Protection System Motor Generator A (RPS-MG-A) to trip. The loss of RPS A power causes an Outboard Nuclear Steam Supply Shutoff System (NSSSS) isolation of Groups 1 (Main Steam Line Drains only), 2, 5, 6, and 7. NSSSS Group 6 isolates Residua'J Heat Removal (RHR) Shutdown Cooling and NSSSS Group 7 isolates Reactor Water Cleanup System (RWCU). In addition, the loss of RPS A power causes an NSSSS Group 3 (Primary and Secondary Containment Ventilation and Purge Systems) isolation including Standby Gas Treatment (SGT) System actuation.

Plant operators restarted RPS-MG-A and restored all systems to their pre-event lineup in less than one hour.

The cause of the event was an inadequate Plant Procedure which failed to provide steps to fully isolate the circuit heing calibrated. This procedural inadequacy allowed a portion of the circuit to become energized and trip a plant lockout relay (E-RLY-86TS) on overcurrent.

y/

NRC Form $ 45 (05$ )

NRC Pone 3SSA U.S. NUCLEAR REOULATORY COMMISSION IS@31 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO OMB NQ. 3150MI04 EXPIRES: 8/31/SS PACILITY NAME I'l OOCKET NUMBER 131 LER NUMBER ISI PACE 131 neerslorr SCOVSNTrAL rrVM Ell )  : NUMeen Washin ton Nuclear Plant - Unit 2 0 5 0 0 0 3 9 8 7 0 1 0 0 0 0 2 OF 0 3 TEXT ///more e/reoe /e eerrierE roe erR/ono/HRC %%dnn 3BSA's/ IITI There is no safety significance associated with this event as no actual Plant condition requiring the Emergency Safety Feature (ESF) actuations existed and all ESF actuations occurred as designed. The reactor cavity was flooded providing a large heat sink, which allows adequate time to restore RHR Shutdown cooling. Shutdown Cooling was restored in less than one hour.

Plant Conditions a) Power Level - OX b) Plant Mode - 5 (Refueling)

Event Description At 1237 hours0.0143 days <br />0.344 hours <br />0.00205 weeks <br />4.706785e-4 months <br /> on May 12, 1987 a Plant electrician inadverently caused the loss of offsite power supply TRS. At that time, power to emergency bus SM-7 was aligned to the TRS supply and, on the loss of TRS, this bus switched automatically to the alternate offsite power supply TRB. The other two Plant emergency buses (SM-4 and SM-8) were unaffected by this event and were aligned to the normal plant power supply (TRN), which in this case was a third offsite power supply.

The loss of power to SM-7 caused RPS-MG-A to trip. The loss of RPS A power caused an NSSSS Outboard Containment Isolation. The outboard isolations occurred for NSSSS Group 1 (Main Steam .Line drains only), Group 2 fReactor Water Sample Valves), Group 5 (Residual Heat Removal and Traversing In-Core Probe) (TIP) Systems, Group 6 (RHR Shutdown Cooling), and Group 7 (Reactor Water Cleanup). Both the RHR Shutdown Cooling and RWCU Systems were in operation at the time of the event and were tripped off by the event.

In addition the loss of RPS A power causes an NSSSS Group 3 (Primary and Secondary Containment Ventilation and Purge System) isolation. The NSSSS Group 3 isolation is caused by loss of power to Reactor Building Exhaust Radiation Monitors a non-NSSSS ESF trip signal. All required Group 3 actions occurred as designed including the automatic start of the Standby Gas Treatment System.

Plant Operators responded by restarting RPS-MG-A and restoring RHR Shutdown Cooling and RWCU within 30 minutes. A total restoration of all systems to their pre-event lineup was completed within one hour.

The event occurred during calibration of the Plant Oscillograph by a plant

. electrician. The Plant Oscillograph is an instrument which monitors performance of the Plant Electrical Systems. The Plant electrician was using a Plant Procedure which did not include steps to fully isolate the circuit being

~

calibrated. This made the circuit polarity sensitive in that the positive and neutral test leads must be connected to specific sides of the test switch used to isolate the circuit being calibrated. The procedure did not provide specific test equipment connection instructions. When the Plant electrician connected the test equipment leads, the positive lead was connected to the unisolated side of the test switch which powered an overcurrent relay as both the test equipment power supply and the overcurrent relay were connected to the same ground. This caused a plant lockout relay to trip, and subsequently tripped the TRS power supply breakers.

rrllc coRM 30IA 1943/

~ ~

NRC Pone 34SA US. NUCLEAR REOULATORY COMMISSION

)483 I 3)50M)0l

~ LICENSEE EVENT REPORT (LERI TEXT CONTINUATION APPROVEO OM8 NO.

EXPIRES: 8/3)/85 PACILITY NAME Ill DOCKET NUMEER (2) LER NUM4ER IS) PACE I3)

YEAR SEOUSNT/AL IIEV<<ION gb~ NUMS SII NUM 4 II Washington Nuclear Plant - Unit 2 o s o o o 3 9 7 8 7 0 1 0 0 0 3 oF0 3 TEXT ///maf <<<<ff /f mSM)<<E I<<f oddUfnf/HitC hnII ~'f/ I )7)

The root cause of the event was an inadequate Plant Procedure. The procedure did not include steps to install a test plug to fully isolate the circuit being calibrated, nor did it include specific instructions, relating to polarity, for connecting the test equipment lead.

Inmediate Corrective Action .

I Plant Operators restarted RPS-MG-A and returned RHR Shutdown Cooling and the RWCU System to operation within 30 minutes. All Plant systems were restored to their pre-event lineup in less than one hour.

The Plant oscillograph calibration was completed using the test pluq to isolate the test switch terminal.

Further Corrective Action The Plant Procedure will be revised to require that the test plug be installed prior to connecting the test equipment. With the test plug installed the circuit to be calibrated is fully isolated and not polarity sensitive.

Safety Siqnif icance There is no safety significance associated with this event because no Plant condition requirinq the ESF actuations existed and all ESF actuations occurred as designed. The loss of RKR Shutdown Cooling was not a problem because the reactor cavity, which was flooded for refueling, provides a large heat sink which allows adequate time to either restore RHR Shutdown Cooling or establish an alternate shutdown cooling path. This event posed no threat to the safety of the public or Plant personnel.

I Similar Events86-008 EIIS Information Text Reference EIIS Reference System Component Offsite Power Supply (TRS) EA Alternate Offsite Power Supply (TRB) EA Reactor Protection System (RPS) JC Reactor Protection System Motor Generator (RPS-MG-A} JC Nuclear Steam Supply Shutoff System (NSSSS) BD Residual Meat Removal System (RHR) BO Reactor Water Cleanup System CE Plant Lockout Relay (E-RLY-86TS} EA Normal Plant Power Supply (TRN) EA Traversing In-Core Probe (TIP) IG Plant Oscillograph EA OSG tandbv Baz Treatment (SGT) eactol suilding Rad~atson Monitor Exhaust NIIC fa<<M 3SSA (943)

0 ~ ~ 0 WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.o. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 Docket No. 50-397 June 11, 1987 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.87-010

Dear Sir:

Transmitted herewith is Licensee Event Report No.87-010 for WNP-2 Plant.

This report is submitted in response to the report requi rements of 10CFR50.73 and discusses the item of reportability, corrective action taken, and action taken to preclude recurrence.

This is a follow-up to the verbal notification given at 1315 hours0.0152 days <br />0.365 hours <br />0.00217 weeks <br />5.003575e-4 months <br /> on Hay 12, 1987.

Very truly ours, C . Powers (H/D 927M)

WNP-2 Plant Manager CHP:ac

Enclosure:

Licensee Event Report No.87-010 cc: Hr. John B. Martin, NRC - Region V Mr. R. T. Dodds, NRC - Site (901A)

INPO Records Center - Atlanta, GA Hs. Dottie Sherman, ANI Hr. D. L. Williams, BPA (H/D 399}

//gg