ML18036A670

LER 92-002-00:on 920403,unexpected ESF Actuation Occurred During Testing of Core Spray Pump Breaker 2C,resulting in auto-start of EECW Pump.Caused by Inadequate self-checking. Red Indicator Light replaced.W/920428 Ltr

ML18036A670
Person / Time
Site:	Browns Ferry
Issue date:	04/28/1992
From:	Ridgell E, Zeringue O TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-002-04, LER-92-2-4, NUDOCS 9205010266
Download: ML18036A670 (18)

Text

ACCELERATED Dj TRJBUTION DEMONS TION SYSTEM REGULATORY INFORMATION 'DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9205010266 DOC DATE: 92/04/28 NOTARIZED: NO DOCKET FACIL'.50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH. NAME AUTHOR AFFILIATION RIDGELL,E.M. Tennessee Valley Authority ZERINGUE,O.J. Tennessee'alley Authority RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 92-002-00:on 920403,unexpected ESF actuation occurred during testing of core spray pump breaker 2C,resulting in auto-start of EECW pump. Caused by inadequate self-checking.

Red indicator light replaced.W/920428 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL'J SIZE:

TITLE: 50..73/50.9 Licensee Event Report (LER), ZncidenMRpt, etc.

NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL SANDERS,M. 1 1 HEBDON,F 1 1 ROSS,T. 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 , AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB10 1 =

1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPBll 2 2

'NRR/DST/SELB 8D 1 1 NRR/DST/SICB8H3 1 1 NRR/DS~T.S+LB8 Dl 1 1 NRR/DST/SRXB 8E 1 1 RE~X-LE,'~~~02 1 1 RES/DSIR/EIB 1 1 GH2,FILE 01 1 1 EXTERNA : EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME-FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL'TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 32 ENCL 32'

ik II i

Tennessee Vatley Authority. Post Office Box 2000, Decattrr,'Atabama 35609 O. J. 'Ike'eringue Vice President, Browns Ferry Operations APR 28 1992 U.S. Nuclear Regulatory'Commission ATTN: Document Control Desk Washington, D.C. 20555

Dear Sir:

TVA BROWNS FERRY NUCLEAR PLANT (BFN) UNIT 2 DOCKET NO. 50-260 FACILITY OPERATING LICENSE DPR-52 LICENSEE EVENT REPORT LER-50-260/92002 The enclosed report provides details concerning an engineered safety features actuation resulting from an inappropriate personnel action.

This report is submitted in accordance with 10 CFR 50.73(a)(2)(iv).

Sincerely,

0. J. Zeringue Enclosure cc: see page 2'2P5Q102 qpp428 PDR ADOCK p5pppp+Q PDR S ~

2 U.S. Nuclear Regulatory Commi'ssion APR 2 8 1992 cc (Enclosure):

INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 Paul Krippner American Nuclear Insurers The Exchange, Suite 245 270 Farmington Avenue Farmington, Connecticut 06032 NRC Resident Inspector Browns Ferry Nuclear Plant

'Route 12,- P.O. Box 637 Athens, Alabama 35609-2000 Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 2900 ~

Atlanta, Georgia 30323 Thierry M. Ross U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852

0 4l:

NRC Form 366, U. LEAR REGUIATORY COtf5ISSION Approved OMB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

FACILITY NAHE (1) r n

, I DOCKET NUMBER (2) I ~~~

TITLE (4)

Y

)SE()UENTIAL iREVISIONi, i D

(,( FACILITY NAMES V V iDOCKET NUMBER(S)

.I I I I I I I 04' I I.

92 I OPERATING I ITHIS REPORT 'IS SUBMITTED PURSUANT TO .THE REQUIREMENTS OF 10, CFR 5:

,,MODE I I f 1 w'n 1 N 120 '02(b) l20.405(c) (~F50.73(a)(2)(iv) 173 '1(b)

POWER i20.405(a)( 1)(i) l50 36(c)(1) 'l50 73(a)(2)(v) i73.71(c)

LEVEL i20.405(a)( l)(ii) i50.36(c)(2) i50.73(a)(2)(vii) iOTHER (Specify in i20.405(a)(l)(iii) F50./3(a)(2)(.i) i50.73(a)(2)(viii)(A) Abstract below and in i20.405(a)( l)(iv) I 'l50.73(a)(2)(i'i) F50.73(a)(2)(viii)(B) Text, NRC Form 366A) v i .7 NAME

'I AREA CODE I i 'n P N T I I I iREPORTABL'El ,I I IREPORTABLEI A YTH MP N N Y T N T T P T 14 I EXPECTED INFANT~D Y I I SUBMISSION I I I N AT ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines) (16)

On April 3, 1992, an unexpected. engineered safety feature (ESP) actuation occurred during testing of the 2C Core Spray (CS) pump breaker. The actuation resulted in the auto-start of the D3 Emergency Equipment Cooling Water (EECW) pump.

In. this event, plant personnel were performing a routine breaker test on the CS breaker. This test requ'ires the breaker, a General Electric (GE) 4160V horizontal breaker, to be racked to the test position and the breaker test switch to be actuated. These actions resulted in the control circuits being energized and the actuation of a 28-second time delay relay. At the time the breaker was placed in test, Operations personnel performing, the test realized that the red indicator light on the CS breaker was not functional and proceeded to replace the indicator. During replacement of the indicator light, the breaker test switch remained closed resulting in timing out of the 28-second time delay relay and the subsequent auto-start of the D3 EECW pump.

The, root cause of this event was inadequate self-checking by Operations personnel

.prior to testing the CS breaker.

t Corrective actions for this event include training of Operations personnel- and personnel corrective action.

NRC Form 366(6-89)

NRC Form 366A U. UCLEAR REGULATORY COHHISSION Approved OHB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAHE (1) IBOCKET NUHBER (2)

I I I I SEQUENTIAL I I REVISION I I I I I Browns Ferry Unit 2 I I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)

I. PLANT CONDITIONS

-Unit 2 was at approximately 100 percent power (power operation). Units 1 and 3 were shutdown and defueled.

II. DESCRIPTION OF EVENT A. tv~at:

On April 3, 1992 an unexpected engineered safety feature (ESF) actuation occurred during testing of 'the 2C Core Spray (CS) [BF] pump breaker. The actuation resulted in the auto-start of the D3 Emergency Equipment Cooling Mater (EECM) [El] pump.

In this event, plant personnel were performing a routine breaker test on the CS breaker. This test requires the breaker, a General Electric (GE) 4160V horizontal breaker, to be racked to the test position and the breaker test switch to be actuated. These actions resulted in the control circuits being energized and the actuation of a 28-second time delay relay. At the time the breaker was placed in test, Operation personnel performing the test realized that the red indicator light on the CS breaker-was 'not functional and proceeded to replace the indicator light.

During replacement of the indicator light, the breaker test switch remained closed resulting in timing out of the 28-second time delay relay and the subsequent auto-start of the D3 EECW pump.

B. t t t t t t t t th gv~t:

None.

C.

April 3, 1992 at 0538 CST The 28-second time delay relay times out and the D3 EECW pump auto-starts.

0540 CST The D3 EECM pump is secured by Operations personnel in the main control room.

0640 CST TVA provided a four-hour, non-emergency report to NRC required by 10 CFR 50.73(a)(2)(iv).

NRC Form 366(6-89)

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, NRC Form 366A U. 5 CLEAR. REGULATORY COHHI SS ION Approved OHB No. 3150-0104 (6-8') ) Expires 4/30/92 LICENSEE, EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAHE (1) )DOCKET. NUHBER (2)

I I iSEQUENTIAL i PREVISION/ ( )

Browns Ferry Uni t 2 I I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)

D.

None.

E.

The event was immediately known to the control room operator upon receiving indication of the EECW pump auto-start.

Operations verified the auto-start of the D3 EECW pump as indicated in the control room.

G. t t All plant systems operated as designed. Specifically, the breaker associated with this event is designed to energize the control logic when placed .in the test position. This resulted in the subsequent time-out of the time delay relay and actuation of the EECW pump.

III. CAUSE OF THE EVENT A.

The immediate cause of this event was inappropriate personnel action.

S. gggt~gggg:

The root cause of this event was inadequate self-checking by Operations personnel prior to testing the CS breaker. Specifically, a sign placed on the outside of the breaker cabinet warned personnel that this breaker would start the EECW pump if aligned for EECW when placed in the test position. Operations personnel did not notice this sign prior to opening the cabinet.

C. t i t t Prior to testing the CS breaker, plant personnel did not refer .to approved plant procedures to determine if specific precautions were applicable.

Instruction (GOI) 300.2, Q~t precautions concerning the

~.

The personnel performing this test had been trained on General Operating possibility This procedure provides specific of ESF actuations when testing the NRC Form 366(6-89)

45 41 NRC Form 366A U. UCLEAR REGULATORY CONNI SS ION Approved ONB No. 3150-0104 (6-89) Exp)res 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NANE (1) (OOCKET NUNBER (2) N B I ( (SEQUEN TIAL ( (REVISION(

Browns Ferry Unit 2 I B I ( I I 4

TEXT (If more space is required, use additional NRC Form 366A's) (17)

CS breakers. Since breaker testing is a routine procedural action, the presence of the procedure is not required. However, it is expected that individuals performing work to approved procedures be aware of the precautions listed in the procedures and if not that they review the procedures for applicable precautions before proceeding with even routine tasks.

A.

The CS pump circuit logic is designed to auto-start associated EECW pumps whenever the CS pump breaker is in the closed position for more than 28 seconds, and the breaker is in either the test position or is racked in.

The auto-start of the EECW pump places the plant in a more conservative configuration with additional EECW pumps running.

In this event, all safety-related plant components operated as expected and the, safety of the plant, its personnel, and the public was not compromised.

V. CORRECTIVE ACTIONS A. t v t Testing of the 4160V CS breaker was completed and the red indicator light was replaced. In addition, pl'ant systems were returned to their normal configuration.

B. t A t tR

l. Individuals involved in this event received personnel corrective actions in accordance with TVA personnel policy.

2. Training will be provided to Operations personnel on the importance of, and management expectations for following procedural requirements even during highly repetitive tasks. In addition, management expectations for self-checking will also be reinforced.

3. Personnel involved in this event had received 2B electrical training which covers the precautions in GOI-300.2. However, to provide assurance of personnel awareness, 2B electrical training will be revised to emphasize this event.

NRC Form 366(6-89)

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NRC Form 366A U.S. N(!CLEAR REGULATORY COHHISSION Approved OHB No. 3150-Oll'4

..(6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION I I FAC L T Y NAME ( 1 ) lOOCKET NUMBER (2)

I ) SEQUENTIAL f ( REVISION )

Browns Ferry Uni t 2 I Y A I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)

4. Even though the personnel involved in this event did not refer to the precautions in GOI-300.2, TVA has determined that this procedure could be enhanced by revising the precaution statement to emphasize the effects associated with the equipment involved in this event.

5. TVA will review the plant design to determine if the present circuit design, including the 28-second time delay relay, is required.

6. TVA has reviewed the plant configuration and determined that the CS pump breakers are the only 4160V breakers 'that have a feature which can cause this type of incident.

VI. ADDITIONAL INFORMTION.

A.

None.

B.

First, the Bl EECW pump auto-started on September 1, 1988, after the 3D CS pump breaker was left in the test closed position for greater than 28 seconds. This incident is documented in LER 50-259/88027. In this incident the breaker was left in the test closed position per,a test procedure and the root cause of the event was determined to be procedural inadequacy.

The corrective actions listed in the L'ER included: 1) revision of GOI-300.2 to provide a caution concerning the auto-start of the EECW pumps, 2) placing the caution label on the outside of the CS pump breaker cabinet, and 3) training plant personnel on the event.

The corrective actions identified above; procedures, labels, and training, all existed at the time of the current event and should have prevented a recurrence. However, due to lack of self-checking by the individuals involved the barriers presented by these corrective actions were broken.

Second, the D3 EECW pump auto-started on February 23, 1991, after the 2B CS pump breaker had been racked into the test position and the test switch actuated. Thi:s incident is documented'n LER 50-260/91003. Although the same components were involved in the February 23, 1991 incident, as in the current event,. the incident is not similar because the breaker was not left in the test closed position for more than five seconds. This was not sufficient for the 28 second time delay relay to time out and actuate the EECW pump.

The root cause of the February 23, 1991 incident could not be determined.

NRC Form 366(6-89)

0 0 NRC Form 366A U. S. NUCLEAR REGULATORY COMMISSION Approved OHB No. 3150-0104

'(6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAHE (1) IDOCKET NUMBER (2)

'I I I I SEQUENTIAL I IREVISIONI I . I I I Browns Ferry Uni t 2 I. I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)

Training will be provided to Operations personnel on the importance of, and management expectations for following procedural requirements even during highly repetitive tasks. This training will be completed by August 1, 1992.

2~ Management expectations for self-checking will be reinforced to Operations personnel. This action .will be completed by August 1, 1992.

3. The 2B electrical training program will be revised to emphasize this event. This revision will be complete by August 1, 1992.

4. The precaution in GOI-300.2 will be revised to -emphasize the effects associated with the equipment involved in this event. This revision will be completed by August 1, 1992.

5 ~ ,TVA will review the plant des'ign to determine if the present circuit design, including the 28-second time delay relay, is required. The design change request to initiate the review will be issued by June 1, 1992.

Energy Industry Identification System (EIIS) codes are identified in the text as [XX].

NRC Form 366(6-89)

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