ML18038B074

LER 94-012-00:on 941113,RHR Shutdown Cooling Valve Inadvertently Closed.Caused by Personnel Failure to Follow Procedure During Surveillance Instruction.Personnel Involved in Event counseled.W/941212 Ltr

ML18038B074
Person / Time
Site:	Browns Ferry
Issue date:	12/12/1994
From:	Hsieh C, Machon R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-94-012-01, LER-94-12-1, NUDOCS 9412220129
Download: ML18038B074 (18)

Text

F'R.IC3R.I CW (ACCELERAT.ED RIBS I'ROCI'.SS 1

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9412220129 DOC.DATE: 94/12/12 NOTARIZED: NO DOCKET FACIL:50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH. NAME AUTHOR AFFILIATION HSIEH,C.S. Tennessee Valley Authority MACHON, R. D. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 94-012-00:on 941113,2A RHR pump trip occurred'hen cooling isolation valve inadvertantly closed causing loss of shutdown cooling. Caused by failure to follow procedure.

Immediate correction re procedure.W/941212 ltr.

DISTRIBUTION CODE IE22T COPIES RECEIVED'TR TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc. 2 ENCL SIZE 3 NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-4-PD 1 1 WILLIAMS,J. 1 1 INTERNAL: ACRS 1 1 AE~O/~/~B 2 2 AEOD/S PD/RRAB 1 1 /'FX LE CENTER 0'2 1 1 NRR/DE/ECGB 1 1 ~NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DISP/PIPB 1 1 NRR/DOPS/OECB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1' NRR/DRSS/PRPB 2 2 NRR/DSSA/SPLB 1 NRR/DSSA/SRXB 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 2 2

'NOAC MURPHY,G.A 1 1 NOAC POORE,W. 1 . 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 YOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO RFDUCE 4VKSTE! CONTACT'I I IE DOC!.'IIENTCOYTROL DESK. ROOXI Pl-37 (EXT. 504.2083 ) TO ELI XII%ATE YOl'R XAXIE FROXI DISTRI!3U1 ION LIS'I'5 FOR DOCI.'ML'i'I'S YO!.'Oi "I'L'I;D!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 28 ENCL 28

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4l '0 Tennessee Vie!r Avthori',y. Post Office Box 2000. Decatv.. A!abaota 35609.2000 R. D. (Rick) Machott Vce Presxfent, Browns Ferry Nvctea. P!aot December 12, 1994 U.S. Nuclear Regulatory Commission 10 CFR 50.73 ATTN: Document Control Desk Washington, D.C. 20555

Dear Sir:

BROWNS FERRY NUCLEAR PLANT (BFN) UNZTS 1~ 2~ AND 3 DOCKET NOS. 50-259~ 50-260~ AND 296 FACILITY OPERATING LICENSE DPR-33I '52~ AND 68 - LZCENSEE EVENT REPORT,(LER) 50-260/94012'he enclosed LER.provides details concerning an event where the residual heat removal outboard shutdown cooling isolation valve was i:nadvertently closed as a result of personnel failure to follow procedure during performance of a surveillance instruction. This report is submitted in accordance with 10 CFR 50.73(a)(2)(v)(B) as an event or condition that alone could have prevented the fulfillment of the safety function of structures or systems that are needed to remove residual heat.

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R. D. Machon Site Vice President Enclosure cc: See page 2 9412220129 941212 PDR ADQCK 05000260 8 PDR

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'U.S. Nuclear Regulatory Commission Page 2 December 12, 1994 cc (Enclosure):

INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta,. Georgia 30339 Paul Krippner American Nuclear Insurers Town Center, Suite 300S 29 South Main Street West Hartford, Connecticut 06107 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens, Alabama 35611 Regional Administrator U.S. Nuclear Regulatory Commission Region 101 II Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. J. F.,Williams, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852

h' NRC FORM 366 U.S. WCLEAR REGULATORY CQtlISSION APPROVED BY (WB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY NITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

LICENSEE EVENT REPORT (LER) FORNARD COHHENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEHEMT BRANCH (HNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, (See reverse for required naker of digits/characters for each block) MASHINGTON, DC 20555-0001 AND TO THE PAPERMORK (3110-0104), OFFICE OF REDUCTION PROJECT MANAGEHENT AND BUDGET MASHINGTON DC 20503.

FACILITY NAME (1) DOCKET NWBER (2) PAGE (3)

Browns Ferr Nuclear Plant BFN Unit 2 05000260 1 OF 6 TITLE (4) A Residual Heat Removal Shutdown Cooling Valve was Inadvertently closed as a Result of Personnel Failure to Follow Procedure during Performance of a Surveillance Instruction EVENT DATE [S) LER MINBER 6 REPORI'ATE 7 OTHER FACILITIES INVOLVED 8 SEQUENTIAL REVISION FACILITY NAME DOCKET NUhiDER HONTH DAY YEAR YEAR HONTH DAY YEAR MUHBER NUHBER NA FACILITY NAHE DOCKET NUHBER 13 94 94 012 00 12 12 NA OPERATING THIS REP(NIT IS SUBMITTED PINISUANT TO THE RENIRE%WS OF 10 CFR: Check one or mor e 11 HODE (9) N 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

PDMER 20.405(a)(1)(i) 50.36(c)(1) X 50.73(a)(2)(v)(B) 73.71(c)

LEVEL (10) 000 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER 20.405(a)(1)(iii) 50 '3(a)(2)(i) 50.73(a)(2)(viii)(A) (Specify in 20.405(a)(1)(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) Abstract below and in Text, 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x) MRC Form 366A LICENSEE CONTACT FOR THIS LER 12 NAHE TELEPHONE NUHBER (include Area Code)

Clare S. Hsieh, Compliance Licensing Engineer (205) 729-2635 C(DEPLETE ONE LINE FOR EACH GNPOMENT FAILURE DESCRIBED IN THIS REPORT 13 REPORTABLE REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEH COMPONENT HANUFACTURER TO NPRDS TO NPRDS SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED MONTH DAY YEAR YES SUBMISSION (lf yes, complete EXPECTED SUBHISSION DATE).

X HO DATE (15)

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On November 13, 1994, at 1546 hours0.0179 days <br />0.429 hours <br />0.00256 weeks <br />5.88253e-4 months <br /> Central Standard Time (CST), the Residual Heat Removal (RHR) outboard shutdown cooling isolation valve (2-FCV-74-47) was inadvertently closed during the performance of Surveillance Instruction (SI) O-SI-4.9.A.l.b-4, "Diesel Generator D Emergency Load Acceptance Test." The closed valve caused a loss of shutdown cooling and resulted in the 2A RHR pump to trip. The shutdown cooling was restored approximately one minute later when operators reopened the closed valve and restarted the 2A RHR pump. This event is reportable in accordance with 50.73(a)(2)(v)(B). The root cause of this event was failure to follow procedure. Both the operator and electrician performing the load acceptance test SI fail to carefully read the procedure. Corrective

'actions to prevent recurrence included the following! counselling the personnel involved in the event, incorporating the event in the incident investigation of recent operational errors, and revising the regulatory reporting requirement site standard practice to include this as example of events to be reported.

4k NRC FORH 366A U.S. NUCLEAR REGULATORY CQQIISSION APPROVED BY MB NO. 3150-0104 (5T92) EXPIRES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COHPLY 1JITH THIS INFORMATION COLLECT ION REQUEST: 50.0 HRS. FORNARD COHHENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AMD RECORDS HANAGEHENT LICENSEE EVENT REPORT BRANCH (HMBB 7714), U.S. NUCLEAR REGULATORY COHHISSIOM, TEXT CONTINUATION lIASHINGTON, DC 20555-0001, AND TO THE PAPERNORK REDUCTION PROJECT (3150-0104) ~ OFFICE " OF'HANAGEHENT AND BUDGETS MASHINGTON, DC 20503 FACILITY NAME (1) DOCKET NQIBER (2) LER NWER (6) PAGE (3)

YEAR SEQUENTIAL REVISION MUHBER NUHBER 2of6 Browns Ferry Unit 2 05000260 12 00 TEXT If more s ce is r uired use edditionei co les of NRC Form 3 66A (17)

PLANT CONDITIONS Unit 2 was in cold shutdown as part of the Unit 2 cycle 7 refueling outage with shutdown (SD) cooling in operation. The reactor vessel head was installed. Units 1 and 3 were shutdown and defueled.

DESCRIPTION OF EVENT A. Event:

On November 13, 1994, at 1546 hours0.0179 days <br />0.429 hours <br />0.00256 weeks <br />5.88253e-4 months <br /> CST, TVA was performing Surveillance Instruction (SI) O-SI-4.9.A.l.b-4, "Diesel Generator D Emergency Load Acceptance Test." While performing the SZ, the Residual Heat Removal (RHR) [BN) outboard SD cooling isolation valve (V] 2-FCV-74-47 was inadvertently closed. The closed valve caused a loss of SD cooling and resulted in a trip of the 2A RHR pump. At the time of the event, the 2A RHR pump was aligned and running in Loop I RHR SD cooling mode.

At 1547 hours0.0179 days <br />0.43 hours <br />0.00256 weeks <br />5.886335e-4 months <br />, operators reopened the closed valve and restarted the 2A RHR pump. The SD cooling valve and RHR pump operated as designed. RHR Loop I was placed back into SD cooling. The SD cooling function of the RHR system was out of service for approximately one minute.

Following further review of this event, November 16, 1994 it was determined on that this was reportable pursuant to 10 CFR 50.72(b) (2) (iii) and 50.73(a) (2) (v) (B) . TVA did not immediately recognize that this event constituted an event or condition alone that could have prevented the fulfillment of the safety function of a structure or system that is needed to remove residual heat., Subsequently, on November 16, 1994, at 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />, a four-hour notification was made to the NRC.

B. Ino erable Structures Com onents or S stems that Contributed to the Event:

None

4l NRC FORH 366A U.S. NUCLEAR REGULATORY CCFIIISSION APPROVED BY (WB NO. 3150-0104 (5 92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COHPLY IIITH THIS IMFORHATION COLLECTION REQUEST: 50.0 HRS. FORNARD COHHENTS REGARDING BURDEN EST IHATE TO THE INFORHATION AMD RECORDS MANAGEHENT LICENSEE EVENT REPORT BRANCH (HMBB 7714), U.S. NUCLEAR REGULATORY COHHI SS I ON ~

TEXT CONTZNUATZON MASNINGTOM, DC 20555-0001, AND TO THE PAPERNORK REDUCTIOM PROJECT (3150-0104), OFFICE .OF MANAGEMENT AND BUDGET, llASNINGTOM, DC 20503 FACILITY NAME (1) DOCKET NIMIBER (2) LER IRMKR (6) PAGE (3)

YEAR SEQUENTIAL REVISION NUMBER NUHBER 3of6 Browne Ferry Unit 2 05000260 94 12 00 TEXT tf more s ce is r ired use additional co ies of NRC Form 366A (17)

C Dates and A roximate Times of Ma'or Occurrencesl November 13, 1994 at 1546 CST The RHR outboard SD cooling isolation valve was closed during the load acceptance test. The closed RHR isolation valve resulted in 2A RHR pump to trip.

at 1547 CST The clo'sed valve was reopened and 2A RHR pump was restarted.

November 16, 1994 at 1330 CST A four-hour nonemergency notification was made to NRC in accordance with 10 CFR 50.72(b)(2)(iii).

D~ Other S stems or Seconda Functions Affected:

None Method of Discove (

The closed RHR isolation valve and the tripped RHR pump were identified by the Operations personnel in the Unit 2 main control room when the valve closure indication and the pump trip alarm were received.

Fo 0 erator Actions:

An Assistant Shift Operations Supervisor (ASOS) licensed) and an electrician were in the process of aligning the (utility, RHR system when they misread a step in the load acceptance test SI. The mistake resulted in a jumper, rather than a boot, to be placed between contacts 5 and 6 of relay 10A-K98B. This )umper caused the SD cooling valve 2-FCV-74-47 to close.

Go Safet S stem Res oases:

None

NRC FORH 366A U.S. NUCLEAR REGULATORY CQOIISSI ON APPROVED BY QGI NO. 3150-0104 (5 92) EXP I RES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COHPLY WITH THIS INFORHATIOH COLLECTION 'REQUEST: 50.0 HRS. FORWARD COHHENTS REGARDING BURDEN ESTIMATE TO THE INFORHATION 'AND RECORDS HANAGEHENT LICENSEE EVENT REPORT BRANCH (HNBB 7714), U.S. NUCLEAR REGULATORY COHHISSION ~

TEXT CONTZNUATZON WASHINGTON, DC 20555-0001, AHD TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF HANAGEHENT AND BUDGET, WASHINGTON, DC 20503 FACILITY NAHE (1) DOCKEt NEER (2) LER H(IVER (6) PAGE (3)

YEAR = SEQUENTIAL REVISION NUMBER NUHBER 4of6 Browne Ferry Unit 2 05000260 94 12 00 TEXT f more s ce is r uired use additional co ies of HRC Form 366A (17)

ZZZ ~ CAUSE OF THE EVENT Ao Immediate Cause:

The placement of a jumper on the 'relay 10A-K98B contacts 5 and 6 immediately caused 2-FCV-74-47 to close. The closed valve isolated RHR shutdown cooling and tripped 2A RHR pump.

B. Root Cause:

The root cause of this event was failure to follow procedure.

Both the ASOS and electrician performing the load acceptance test did not carefully read the procedure. As a result, step 7.3.17 of the load acceptance 'test SZ, which specifies the installation of a "contact boot" on contacts 5 and 6 of relay 10A-K98B, was misread instead as installation of a "jumper."

C. Contributin Factors:

None IV. ANALYSIS OF THE EVENT The loss of RHR SD cooling can occur only during the low-pressure portion of a 'normal reactor shutdown and cooldown. At the time of this event, the RHR system was operating in the SD cooling mode. The SD cooling function of the RHR system had been placed into service after the reactor was shutdown a'nd was reduced to less .than 50 psig.

The outboard valve was opened for Loop I RHR SD cooling to supply

=

water to the RHR pumps for cooling recirculation flow.

There were no reactor safety problems from this event. Although the closure of the outboard SD cooling valve caused the RHR system SD cooling suction line to become inoperative, the loss of the SD cooling (for approximately one minute) did not cause the reactor pressure or coolant temperature to increase. Operators could. have manually opened the outboard isolation valve to restore normal SD cooling, Moreover, the reactor water cleanup system and control rod drive if needed.

system can also be used to remove decay heat and maintain reactor water level.

41 NRC FORM 366A U.S. NUCLEAR REGULATORY CQIIISSION APPROVED BY (NGI NO. 3150-0104 (5"92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY lllTM THIS INFORMATION COLLECTION REOUEST: 50.0 HRS ~ FORIIARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT LZCENSEE EVENT REPORT BRANCH (MHBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, TEXT CONTZNUATZON NASHINGTON, DC 20555-0001, AND TO THE PAPERllORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET/

NASHINGTON, DC 20503 FACILITY NAME (1) DOCKET NINIBER (2) LER NWBER (6) PAGE (3)

TEAR SEQUENTIAL REVISION NUMBER NUMBER Sof6 Browns Ferry Unit 2 05000260 94 12 00 TEXT If more s ce is r ired use edditionsi co ies of NRC Form 366A (17)

V. CORRECTZVE ACTZONS A. Immediate Corrective Actions:

After being informed by the main control room operators about the closed SD cooling valve, the ASOS verified that the jumpering of relay contacts in step 7.3.17 was the cause for the closed valve. The jumper was then removed and replaced with a contact boot. Operators reopened the closed valve and restarted the tripped RHR pump.

B~ Corrective Actions to Prevent Recurrence:

1. Both the ASOS and the electrician were counselled on this event and the importance in following procedure.

2. TVA is currently conducting an incident investigation (ZZ) of recent operational errors to determine root causes and develop long term corrective actions. This event has been incorporated into this ZZ.

3. To ensure that similar events in the future are reported promptly, TVA will revise SSP-4.5, "Regulatory Reporting Requirements," to note that this is an example of the type of events that are to be reportable under 10 CFR 50.73(a)(2)(v). This revision will be included in the licensed operators required reading package.

4. As an interim action, this LER will be distributed to operations and licensing personnel to heighten their awareness on the reportability aspect of this event.

VZ ~ ADDZTZONAL ZNFORKLTZON A. Failed Com onents:

None

4k I

I NRC FORil 366A U.S. NUCLEAR REGULATORY CQHISSION APPROVED BY (NGI NO. 3150-0104 (Si92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY lllTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORIIARD COMMENTS REGARDING

, BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT LICENSEE EVENT REPORT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, TEXT CONTZNUATZON NASHINGTOH, DC 20555-0001, AND TO THE PAPERNORK REDUCTION PROJECT (3'150 0104) g OFFICE OF MANAGEHEHT AND BUDGET ~

.MASHINGTOH, DC 20503 FACILITY NAME (1) DOCKET NIHSER C2) LER NLNSER C6) PAGE (3)

YEAR SEQUENT IAL REVISION NUHBER NUMBER 6of6 Browns Ferry Unit 2 05000260 94 12 00 TEXT If more s ce is r ired use additional co ies of NRC Form 366A (1/)

B. Previous LERs on Similar Eventsl TVA has reviewed previous BFN LERs to determine events have occurred. Several LERs have been written as a if similar result of personnel failure to follow procedure. None of these LERs resulted in a loss of SD cooling. However, there were two previous SD cooling loss events (i.e., LER 259/84012 and 259/85037) caused by electrical component failure.

~ LER 259/84012 addressed the failure of the RHR inboard SD cooling valve to open. The valve was opened manually. The event was caused by the failure of the B phase winding of the valve motor.

~ LER 259/85037 discussed problems in establishing SD cooling due to a failed RHR isolation relay following an inadvertent containment isolation.

VIZ+ Conunitments TVA will revise SSP-4.5 to note this as an example to be reportable under 10 CFR 50.73(a)(2)(v) and will be included in the licensed operators required reading package by February 28, 1995.

2 ~ This LER will be distributed to operations and licensing personnel to heighten their awareness on the reportability aspect of this event by January 12, 1995.

Energy Industry Identification System (EIIS) system and component codes are identified in the text with brackets (e.g., [XX)).

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