ML18036B116

LER 92-006-00:on 921203,3D EDG Inadvertently Started & EDG Ground Alarm Received in Control Room.Caused by Short Circuit in Test Leads Connected to EDG Start Circuit.Faulty Test Leads replaced.W/921228 Ltr

ML18036B116
Person / Time
Site:	Browns Ferry
Issue date:	12/28/1992
From:	Shingleton E, Zeringue O TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-006-03, LER-92-6-3, NUDOCS 9301040253
Download: ML18036B116 (18)

Text

A.CCEI ERAT ~ DOCUMENT DISTRJ~UTION SYSTEM REGULATE~ INFORMATION DISTRIBUTION SYSTEM ( RIDS )

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',ACCESSION NBR:9301040253 DOC.DATE: 92/12/28 NOTARIZED: NO DOCKET FACIL:50-296 Browns Ferry Nuclear Power Stati:on, Unit 3, Tennessee 05000296 AUTH. NAME . AUTHOR'FFILIATION SHINGLETON,E.B. Tennessee Valley Authority ZERINGUE,O.J. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION R

SUBJECT:

LER 92-0'06-00:on 921203,3D EDG inadvertently started & EDG ground alarm received in control room. Caused by short D circuit in test. leads connected to EDG start circuit. Faulty test leads replaced.W/921228 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR J ENCL .I SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

.NOTES: A RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL' ID CODE/NAME LTTR ENCL D SANDERSgM. 1 HEBDON,F 1 1 WILLIAMSPJ. 1 1 D'

'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/LHFB1'0 1 1' NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB8H3 1 1 NRR BS&/N LB8D1 1 1 NRR/DST/SRXB 8E 1 . 1 REG'ILE 02 1 1 RES/DSIR/EIB 1 1 GN ILE 01 1 1 EXTERNAL: EG&G BRYCEPJ.H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POOREPW' 1 1 NUDOCS FULL TXT 1 1 D

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PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

'FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 31 ENCL 31 pP@

t Tennessee valley Authority. Post Ofirce Box 2000. Decatur, Alabama 35609-2000 O. J. "Ike" Zeringue Vice President. Browns Ferry Nuclear Plan!

DEC 88 >99z U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555

Dear Sir:

TVA BROWNS FERRY NUCLEAR PLANT (BFN) UNITS 1, 2, AND 3 DOCKET NOS.

50-259, 260, AND 296 FACILITY OPERATING LICENSE DPR-33, 52, AND 68 LICENSEE EVENT REPORT LER-50-296/92006 The, enclosed report provides details concerning an inadvertent emergency diesel generator (EDG) start due to a short circuit that occurred during EDG testing.

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

Sincerely,

(~., ~'..'.i~ r,II

0. J. Zeringue Enclosure cc: See page 2 OgOO8 <

930i040253 05000296 9'21228'DR ADOCK PDR S

U.S. Nuclear Regulatory Commission DFC 88 1992 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, 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 NRC Form 366 NUCLEAR REGULATORY COSGSSION Approved,OHB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE'EVENT REPORT (LER)

FACILITY NAHE (1) IDOCKET NUMBER (2) I~PA r wn F rr N 1 r BFN F TITLE (4) Inadvertent Emergency Diesel Generator (EDG) Start During Testing Due To A Short Circuit.

'EVENT OAY E N M TH A L V D

) SEQUENTIAL ) REVISION [

FACILITY NAHES, ) DOCKET NUHBER(S)

NTH A Y YEA N HB N MBE 'TH (

AY

]

R

]

N A I I I I I I I I I I I 1

OPERATING I ITHIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREHENTS OF 10 CFR $ :

HODE J ) h n m r ll N i20.402(b) )20.405(c) I)L,ISO'3(a)(2)(iv) [73.71(b)

POWER )20.405(a)(1){i) (50.36(c){l) J

)50.73{a)(2){v). )73.71(c)

LEVEL I l20..405(a) (1) (i i ) (50.36(c)(2) [ (50.73(a)(2)(vii) [OTHER (Specify in 1 (20.405(a) (1) (i i i) )50.73(a)(2){i)(B)) (50.73{a){2){viii)(A)') Abstract below and in I 1 20.405(a) (1) (i v) )50.73(a)(2)(ii) ] )50.73(a)(2)(viii)(B) ) Text, NRC Form 366A) 1 v 1 LI EN EE NTA T F THI LER 12 NAME I E PM N N MB R

) AREA CODE )

8 hin 1 n li n Li n in n in r 2 2 2 HPLETE NE INE FR H MPNN FA REDE R BD INTHI EP RT 1

[REPORTABLE) l I I I IREPORTABLE/

A E Y TEH MP NENT MAN FA T R T NPRD A E Y TEM HP N NT HAN FA T ER T NPRO PPLEHENTA R P RT EXP T D 14 I I SUBHISSION I I I YE If m 1 XPE TEO BH I N OAT X N DATE 1 ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines) (16)

On December 3, 1992,, at 1220 hours0.0141 days <br />0.339 hours <br />0.00202 weeks <br />4.6421e-4 months <br />, during performance of the diesel generator 3D redundant start test, the 3D emergency diesel generator (EDG) inadvertently started and an EDG ground alarm was received in the control room. As part of this test, test leads are connected across the EDG autostart relay. As personnel were initiating the test, the EDG started when the test leads vere shorted. Operations personnel reset the alarm, performed an inspection of the EDG and secured it at approximately 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />. At the time of the event, Unit 3 was defueled.

The short was due to a degraded test lead that was further. damaged when it was pinched under a movable handle on the test equipment. TVA vill replace test leads on the test equipment and reroute and secure them in such a way to prevent, future damage. The movable handles on the -test equipment vill be removed to prevent the possibility of future damage to test leads. TVA will establish an administrative control program to address test lead inspection, repair and/or replacement.

NRC Form 366(6-89)

a' NRC Form 366A (6-89)

U ~ S. CLEAR REGULATORY COHHISSION LICENSEE EVENT REPORT (LER)'EXT t Approved OHB No. 3150-0104 Expires 4/30/92 CONTINUATION FACILITY NAHE (1)' (OOCKET NUHBER (2) H P I- (SEQUENTIAL ( (REVISION(

NME Ferry Uni t Browns 3 I Y R H I I I I I F TEXT (If more space is required, use additional NRC Form 366A's) (17)

I PLANT COHDITIOHS Units 3 and 1 were defueled. Unit 2 was operating at approximately 2605 MM thermal and coasting down for a refueling outage. Emergency Diesel Generator (EDG) 3D was being'eturned to service after its scheduled annual inspection.

C II. DESCRIPTIOH OF SVEHT A. svent:

On December 3, 1992, at 1220 hours0.0141 days <br />0.339 hours <br />0.00202 weeks <br />4.6421e-4 months <br />, during performance of EPI-3-082-DGZ004, Diesel Generator 3D Redundant Start Test, the 3D'DG

[EK] inadvertently started. As part of this test, test leads are connected across the EDG autostart relay [RLY]. After personnel connected the leads and initiated the test, the EDG started when the test leads were shorted. All personnel exited the EDG room and the Unit Operator (UO) was contacted. The UO advised that a "DIESEL GEN 3D CONTROL CIRCUIT GROUND" alarm was received in the control room simultaneously with the EDG start.

Test personnel reentered the EDG room and visually verified that 'the ground meter was indicating a ground on the control circuit. Test personnel verified that the ground was caused by the test leads connected across the autostart relay. Subsequently, visual inspection of the leads identified damage and exposed conductors on both leads. Operations personnel then reset the alarm, performed an inspection of the 3D EDG and secured the EDG at approximately 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />. The damaged test leads were replaced and the redundant start test was successfully completed.

This event is b'eing reported in accordance with 10 CFR 50.73(a)(2)(iv) as an event or condition that resulted in a manual or automatic actuation of an ESF.

B. Ino crab 'e tructures Com onents o S stems that Contributed to the None.

C. Dates d ox mate imes o o Occu r ces November 30, 1992 at 0700 EDG 3D tagged out to perform annual inspection.

December 3, 1992 Annual inspection completed and EDG ready for Redundant Start Test.

NRC Form 366(6-89)

P

I NRC Form 366A U.S. CLEAR REGULATORY COHHISSION Approved OHB No. 3150-0104 (6-89) Expires 4/30/92

'LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAHE (1) IDOCKET NUHBER (2) R H p I I I I SEQUENTIAL I I REVI SION I I I I I Browns Ferry Unit 3 I EA NH NHER I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)

December 3, 1992 at 1215 Test equipment positioned and test leads connected.

December 3, 1992 at 1220 EDG 3D fast starts when personnel initiate test.

December 3, 1992 at 1300 EDG ground alarm reset, EDG inspection performed, and EDG secured.

December 3, 1992 at 1522 Four-hour report made to the NRC per 10 CFR 50.72(b)(2)(ii).

D. 0 her S stems o S co da o fected:

None.

B. Method of D scove The EDG start was immediately recognized by test personnel in the 3D diesel generator room and by control room personnel upon receipt of indications in the control room.

F. 0 erator Actions:

Operations personnel requested test personnel to disconnect test leads in the reverse order of installation while observing the ground indication meter. When the leads across EDG autostart relay were removed, the ground indication cleared. Operations personnel reset the alarm, performed an inspection of 3D EDG and secured the EDG at approximately 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />.

G. Safet S stem Res onses:

I The, EDG started as designed.

NRC Form 366(6-89)

.II NRC Form 366A (6-89)

U.S. CLEAR REGULATORY COHHISSION LICENSEE EVENT REPORT (LER) t Approved OHB No. 3150-0104 Expi res 4/30/92 TEXT CONTINUATION FACILITY NAME (1) IOOCKET NUHBER (2) PA I I I I SEQUENTIAL I I REVISION I I I I I Browns,Ferry Unit 3 "I Y R N HBER N MB I I I I 4 F TEXT (If more space is required, use additional NRC Form 366A's) (17)

III. CAUSE OF THE EVEHT Immediate Cause.

The EDG start was caused by a short circuit in the test leads connected to the EDG start circuit. This short was confirmed by a 500-volt Megger test.

The short was due to a degraded test lead that was further damaged when it was pinched under a moveable handle on the test cart (test equipment used for the redundant start test was located on a test cart).

C. Cont buti act Contributing to this event was the design of the test cart and the lack of an administrative control program for controlling test leads.

IV. AHALYSIS OF THE EVEHT Annual maintenance on EDG 3D had just been completed and, as part of return to service activities, test personnel were preparing to perform the redundant start test. The EDG was inoperable per BFN Technical Specifications pending completion of this test and the operability run.

Placement of the defective test leads across the EDG autostart relay contacts

-effectively gave the EDG logic an autostart signal as soon as the ground circuit path was completed. The short energized the fast start relay in the diesel start circuit, which led to the EDG fast start. The EDG, was left running while the test leads were removed and the ground indication was cleared. There were no operational problems encountered during the EDG start, run, or shutdown.

This event had no safety significance.

NRC Form 366(6-89)

Cl NRC Form 366A (6-89)

U.S. LEAR REGULATORY COHHI SSION LICENSEE EVENT REPORT (LER)

TEXT. CONTINUATION t Approved OHS No. 3150-0104 Expires 4/30/92 FACILITY NAHE (1) (DOCKET NUHSER (2) H PA I I I I SE(lUENTIAL, i / REVISION I I I I I Srowns Ferry Unit 3 I H

2 2 F TEXT (If Nore space is required, use additional NRC Fore 366A's) (17)

V. CORRECTIVE ACTIONS

h. mmediate Correct ve Actions:

The test leads were disconnected in reverse order of installation while observing the ground indication meter. The ground indication .cleared when the test leads connected across the autostart relay were removed.

Operators reset the alarm, performed an inspection of the EDG and secured the EDG at approximately 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />. The faulty test leads were replaced=

and the redundant start test was successfully completed.

B. Co rective Actions to P e en Recurrence:

1. TVA will replace all test leads on the two test carts used to conduct the redundant start test. Replacement leads will be rerouted and secured to the test carts in such a way to prevent future damage.

2. TVA will remove the movable handles on the test carts to prevent the possibility of=future damage to test leads.

,3.. TVA will establish an administrative control program to address test lead inspection, repair and/or replacement.

VI. ADDITIONAL INFORMATION A. ai ed Com onents:

None.

B. re o s LERs S mi a si There have been numerous previous licensee event reports (LERs) due to inadvertent EDG starts, and due to inadvertent equipment actuations caused by electrical shorts. However, these events had different root causes.

LER 50-296/87004 reports an inadvertent EDG start that occurred during the performance of the redundant start test and was caused by an electrical short in test leads. This short was caused by personnel error when the individual connecting the test leads allowed them to contact one another.

.Corrective actions were directed toward preventing similar personnel errors.

NRC Form 366(6-89)

0 0 v

NRC Form 366A (6-89)

U.S.. LEAR REGULATORY COHHISSION LICENSEE EVENT REPORT (LER) t Approved,OHB No. 3150-0104 Expires 4/30/92 TEXT CONTINUATION FACILITY NAHE (1). iDOCKET NUHBER (2)

I I I ISEQUENTIAL I IREV>>IONI I I I I Browns Ferry Unit 3 I Y H HB TEXT (If more space is required, use additional NRC Form 366A's) (17)

VII. COMNITHEHTS

1. TVA will replace test leads on the two test carts used to conduct the redundant start test. 'Replacement leads will be rerouted and secured to the test carts in such a way to prevent future damage. TVA expects to complete this action by February '9, 1993.

2. TVA will remove:-the movable handles on the test carts to prevent the this possibility of future damage to test leads. TVA expects to complete action by February 9, 1993.

3. TVA will establish an administrative control program to address test lead inspection, repair and/or replacement.'VA expects to complete this by July 9, 1993.

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

NRC Form 366(6-89)

0 0 f:

,t