ML17284A416

LER 88-021-00:on 880530,outboard Nuclear Steam Supply Shutoff Sys Group 6 Automatically Isolated.Caused by Inadvertent Removal of Trip Logic Circuit Fuse by Licensed Operator.Operator counseled.W/880629 Ltr

ML17284A416
Person / Time
Site:	Columbia
Issue date:	06/29/1988
From:	Powers C, Wyrick T WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-88-021, LER-88-21, NUDOCS 8807110182
Download: ML17284A416 (7)

Text

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'C CELEMTED 3I BUTION DEMONSTRXI'ION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR-8807110182 DOC.DATE: 88/06/29 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION WYRICK,T.R. Washington Public Power Supply System POWERS,C.M. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 88-021-00:on 880530,nuclear steam supply shutoff sys R Group 6 isolation.

W/8 ltr. I DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR ( ENCL / SIZE:

TITLE: 50.73 Licensee Event Report (LER), Incident Rpt, etc.

NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 ~

PD5 PD 1 1 SAMWORTH,R 1 1 D

INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/NAS 1 ' 1 AEOD/DSP/ROAB 2 2 AEOD/DS P/TPAB 1 1 9 ARM/DCTS/DAB 1 1 DEDRO 1 . 1 NRR/DEST/ADS 7E 1 0 NRR/DEST/CEB 8H 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB 7 1 1 NRR/DEST/MEB 9H 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB 8D 1 1 NRR/DEST/RSB 8E 1 1 NRR/DEST/SGB 8D 1 1 NRR/DLPQ/HFB 10 1 1 NRR/DLPQ/QAB 10 1 1 NRR/DOEA/EAB 11 1 1 NRR/DREP/RAB 10 1 1 NRR/DREP/RPB 10 2 2

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NRR/DRIS/4IB 9A 1 1 NUDOCS-ABSTRACT 1 1 G PILE~ 02 1 1 RES TELFORD,Z 1 1

~DE/EIB 1 1 RES/DRPS DEPY 1 1 RGN5 FILE 01 1 1 EXTERNAL EG&G WILLIAMSg S 4 FORD BLDG HOY,A 1 R" H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS,Z 1 1 NSIC MAYS,G 1 1 D

8 l.

A D

TOTAL NUMBER OF COPIES REQUIRED: LTTR 45 ENCL 44 1

NAC Form 388 US. NUCLEAR AEOULATOAYCOMMISSION (843 I APPROVEO OMB NO. 3(50010C LICENSEE EVENT REPORT (LER) EXPIAES: 8/31/88 FACII.ITY NAME (1I DOCKET NUMBER (2) PAOE 3 0 5 0 0 0 3 l OF 4

"'"'"'Nuclear Steam Supply Shutoff System Group 6 Isolation Due to De-energization of the

- Due to Personnel Error EVENT DATE (5) LER NUMB'ER LS) R EP0 RT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH OAY YEAR c8c3 sEDUENTIAL c RSYOOO" OAY YEAR FACILITYNAMES DOCKET NUMBER(S)

~?85 NUMBER NUMSEII MONTH 0 5 0 0 0 0 0 6 29 88 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T0 THE REOUIREMENTS OF 10 CFR ((: (Chrcft one or morr of the followlnpl l11 OPEAATINO MODE (8) 20A02(ir) 20AOS(c) 50.73(e I (2) I Iv) 73.71(Ir)

POWER 20AOS(el(1)(ll 50.38(cl (1) 50,73(el(2)(vl 73.71(cl LEVEL (10) 20A05(e)(1)(ill 50.38(cl(2) 50.73(el(2) (vEI OTHER (Specify ln Ahrtrect 20AOS4) llI (rii) hrfowrnrf in Trit, HRC F~

50,73(el (2) I 0 50.73(el(2) (rill)(Al 366AI 20AOS(el(1) (iv) 50.73(el(2) (8) 50.73(el(2)(vill((BI 20AOS(e) Ill(rl 50.73(e) (2)(ill) 50,73( ~ I(2) I x I LICENSEE CONTACT FOR THIS I.ER (12I NAME TELEPHONE NUMBER AREA CODE COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC EPORTABLE MANUFAC. EPOATABLE TURER TO NPADS CAUSE SYSTEM COMPONENT TURER TO NPRDS ERWa.MBPIjk FIN@~ ISINII

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SUPPLEMENTAL REPORT EXPECTED (Iel EXPECTED SUBMISSION

'ONTH DAY YEAR DATE (15)

YES (if yer, complete EXPECTED StfphtlSSIDH DA TEI NO ASSTRACT (Llmlt to tr00 rprcrr, l.r., rpproximetrly fifteen rlnplr rprce typrwrirtrn linn) IISl On May 30, 1988, at 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br />, while in Plant Mode 5 (Refueling) with the reactor head removed, the reactor cavity flooded, and the fuel pool gates removed, the Outboard Nuclear Steam Supply Shutoff System (NS4) Group 6, automatically isolated. At the time of this event Residual Heat Removal (RHR) Shutdown Cooling Loop A was in operation and was isolated as a result of this event.

The cause of this event was the de-energization of the Nuclear Steam Supply Shutoff System (NS4 ) Group 6 trip logic circuit caused by the inadvertent removal of the circuit fuse by a Licensed Control Room Operator (CRO).

An outboard NS4 Group 6 actuation isolates the Outboard Residual Heat Removal (RHR)

Shutdown Cooling Supply Valve (RHR-V-8), Outboard RHR Shutdown Cooling Return Valves (RHR-V-53A and 53B), and Outboard RHR to Reactor Mead Spray Valve (RHR-V-23). In addition, closing RHR-V-8 will cause both RHR Pump 2A and 2B to trip For this event the closure of RHR-V-8 caused RHR pump 2A to trip.

if no other suction path is available.

Both RMR-V-53B and RMR-V-23 were closed prior to the event.

The root cause of this event is a skill based personnel error. Contributing= factors which led to this event are the lack of a positive method for fuse identification and inconsistently installed fuse identification clips throughout the control room panels.

Plant operators responded by reinserting the trip logic circuit fuse and by returning RHR Shutdown Cooling Loop A to operation within 20 minutes. Returning RHR Shutdown Cooling Loop A to operation also returned all NS4 Group 6 components to their pre-event status.

8807iiOi82 880629 PDR ADOCK 05000397 NRC Form 388 S PDC (8 83 I

NRC fena 388A U~ NUCLEAR REOULATORY COMMISSION I883)

LICENSEE EVENT REPORT {LER) TEXT CONTINUATION APPROVED OM8 NO. 3IEOWIOS EXPIRES: 8/3I/88 fACILITYNAME Ill POCKET NUMEER (1l LER NUMSER ISI PACE I3)

SEOVENTIAL REVISION NVMSSR NVM Sll Washington Nuclear Plant - Unit 2 o s o o o 3 9 7 8 8 021 00 02o" 04 TEXT /1 AIOrS <<War k /SSSSSSL Vse <<S/EkAA///RC FenII 3//Elk/ I Ill Abstract (Cont'd)

The CRO was counseled on the importance of close attention to detail. The Operations department has implemented a double verification program requiring two licensed

'perators to verify the fuse location prior to removing and during the reinstallation of small fuses. Additionally, all fuse identification clips will be removed from the control room panels.

There is no safety. significance associated with this event. RHR Shutdown Cooling .was returned to operation within the allowable Technical Specification Action Statement time limit.

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

Event Descri tion At 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br /> on May 30, 1988 while in operational condition 5 with the reactor head removed, the reactor cavity flooded and the fuel pool gates removed, the Outboard Nuclear Steam Supply Shutoff System (NS4) Group 6, automatically isolated when a Licensed Reactor Operator inadvertently de-energized the NS4 Group 6 circUit by removing the circuit fuse. An outboard NS4 Group 6 actuationtripisol'ates logic the Outboard Residual Meat Removal (RHR) Shutdown Cooling Supply Valve (RHR-V-8),

Outboard RHR Shutdown Cooling Return Valves (RHR-V-53A and 53B), and Outboard RHR to Reactor Mead Spray Valve (RMR-V-23). At the time of this event RHR Shutdown Cooling Loop A was in operation and isolated as a result of this event. In addition, closing RHR-V-8 will cause both RHR Pump 2A and 2B to trip available, and for this event caused RHR pump 2A to trip. Both RHR-V-53B and if no other suction path is RHR-V-23 were closed prior to the event.

At 1425 hours0.0165 days <br />0.396 hours <br />0.00236 weeks <br />5.422125e-4 months <br /> on May 30, 1988 RHR Shutdown Cooling was re-established using RHR Loop A.

A Licensed Operator was executing a Clearance Order which required pulling fuse ¹3 on fuse block BB located in control room panel P623. The Licensed Operator failed to recognize fuse ¹1 because it was covered by a fuse identification clip and started counting down from fuse ¹2. Fuses 2, 3, 4 and 5 had no identification clips on them making them very visible. Because he started counting from fuse ¹2 rather than ¹1, he inadvertently pulled fuse ¹4 rather than ¹3, causing the event.

Immediate Corrective Action Plant Operators responded by re-inserting fuse ¹4. RHR Shutdown Cooling was re-established using RHR Loop A within 20 minutes, which returned all NS4 Group 6 components to there pre-ev'ent status.

NRC PORM SSSA IS<<3I e U.S.OPO:10850524 538/455

NRC farm 344A US. NUCLEAR REOULATORY COMMISSION (1HQI LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3150 0104 EXPIRES: 5/31/BB fACILITYNAME (I I DOCKET NUMBER 12I LER NUMBER (SI PACE (3I EECUENTIAL 'q: NEVEIION

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NUMEEII ', NUM 4/I Washington Nuclear Plant - Unit 2 ,

p 6 p p p 3 9 7 8 8 021 00 0 3 oF 0 4 TEXT //mt/4 <<ect /4 /EEUPNL UM atM/one/NRC %%d/m 33LEB/ l171 Further Evaluation and Corrective Action A. Further Evaluation The immediate cause of the event was the de-energization of the NS4 Group 6 trip logic circuit caused by the inadvertent removal of the trip logic circuit fuse. The root cause of this event is a skill based personnel error, and Plant procedures did not contribute to the event.

A contributing cause of this event is inconsistent application of fuse

.i denti ficati on cl i ps which are randomly instal 1 ed on smal 1 fuses throughout 'the control room panels. When looking face on at a terminal strip .with a fus6 identification clip installed, the fuse is completely blocked from view. Another contributing factor is the lack of a positive method for identification of small fuses.

2. The Nuclear Steam Supply Shutoff System is an Engineered Safety Feature arid this event is therefore reportable per 10CFR5073(a)(2)(iv).

3. There were no structures, components, or. systems inoperable prior to the event that contributed to the event.

B. 'urther Corrective Action

1. The Licensed Operator was counseled on the importance of d1ose attention to detail.

2. The Operations department has implemented a double verification program requiring two licensed operators to verify a fuse location prior to removing and during the reinstallation of small control room fuses.

3. Fuse identification clips will be removed from all control room panel fuse blocks to provide consistency and eliminate any confusion.

4~ During the investigation t of thi s event, i was noted that panel arrangement drawings 1 ocated insi de control room panel s are not controlled documents and, as a result the . potential exist for the drawings to be inaccurate. Although, these drawings did not contribute to this event, such drawings will be removed to prevent any inaccuracy or future confussion regarding fuse location.

5. A technical evaluation will. be performed to determine the best method for identifying small fuses in the main control room.

NRC POIIM 344A (543) t U.S.OPO: 10554P524.535/455

l NRC SwM 358A UA. NUCLEAR REOULATORY COMMISSION

)843)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO OM8 NO. 3)EO&lde EXPIRES: 8/31 /88 SACILITY NAME III OOCKET NUMSER I2) LER NUMEER (dl ~ AOE I3)

YE AR yÃeoI) 5EQUENTIAL Reve)lorn NUMIER NUM55R Washington Nuclear Plant - Unit 2 0 s 0 0 o 3 9 7 8 8021 0 0 0 4 o" 0 4.

TEXT /SIImmm <<seem /I /55UNNL Uee a/Mone/H/IC %%dnm OSSAEJ IIT)

Safety Si nificance There is no safety significance associated with this event. RHR Shutdown Cooling was restored within the Plant Technical Specification Action Statement time limit. And, at the time of the event the reactor water level was greater than 22 feet above the reactor vessel flange which provides a large heat sink for core cooling and adequate time to restore RHR Shutdown Cooling or initiate an alternate decay heat removal method. Additionally, no Plant condition requiring the NS4 Group 6 isolation existed and all NS4 Group 6 isolations occurred as designed. This event posed no threat to the health and safety of either the public or plant personnel.

Similar Events None EIIS Information Text Reference EIIS Reference

~Sstem ~Com onent Nuclear Steam Supply Shutoff System (NS4) BD Residual Heat Removal (RHR) Shutdown Cooling Loop A BD

'SV RHR Shutdown Cooling Supply Valve (RHR-V-8)i BO Outboard RHR Shutdown Cooling Return Valves (RHR-V-53A and 53B) BO ISV Outboard RMR to Reactor Mead Spray Valve (RHR-V-23) BO . ISV RHR Pumps 2A and 2B BO P NRC SO<<M 555A *U.S.OPO:I8884424.838/Add

)843)

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 Docket No. 50-397 June 29, 1988 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.88-021

Dear Sir:

Transmitted herewith is Licensee Event Report No.88-021 for the WNP-2 Plant.

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

Very truly yours, 844 C.M. Powers (M/D 927M)

WNP-2 Plant Manager CMP:lg

Enclosure:

Licensee Event Report No.88-021 cc: Mr. John B. Martin, NRC - Region V Mr. C.J. Bosted, NRC Site (M/D 901A)

INPO Records Center - Atlanta, GA Ms. Dottie Sherman, ANI Mr. D.L. Williams, BPA (M/D 399)