ML18036B333

LER 93-005-00:on 930520,ESF Actuation Occurred Due to Lifted Lead on MSIV Solenoid Circuit.Caused by Personnel Error. Plant Mods Training Handbook Will Be revised.W/930621 Ltr

ML18036B333
Person / Time
Site:	Browns Ferry
Issue date:	06/21/1993
From:	Jay Wallace, Zeringue O TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-93-005-01, LER-93-5-1, NUDOCS 9306290202
Download: ML18036B333 (18)

Text

ACCELERATED DOCVMENT DISTRIBUTION SYSTEM REGULARLY INFORMATION DISTRIBUTIYSTEM (RIDE)

ACCESSION NBR:9306290202 DOC.DATE: 93/06/21 NOTARIZED: NO DOCKET FACIL:50-260 Browns Ferry Nuclear Power Stat'ion, Unit 2, Tennessee 05000260 gUTH.NAME AUTHOR AFFILIATION WALLACE,J.E. Tennessee Valley Authority ZERINGUE,O.J. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 93-005-00:on 930520,ESF actuation occurred due to personnel error for failing to identify impact for removal of neutral lead.C/As:Reset alarms 6 PCIS 6 components returnedto standby readiness status.W/930621 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

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

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME'D2-4-PD LTTR ENCL PD2-4 1 1 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/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DORS/OEAB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRIL/RPEB 1 1 NRR/DRSS/PRPB 2 2 -NEO'/JXSS'A/4PLB 1 1 NRR/DSSA/SRXB 1 1 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: EGSrG BRYCE,J.H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHYFG.A 1 1 NSIC POOREFW ~ 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACI'HE DOCUMENT CONTROL Pl-37 (EXT. 504-2065) TO EUMINATEYOUR NAME FROM DISIRIBUTION DESI'OOM LISIS FOR DOCUMENTS YOU DORT NEED!

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

~ II '

'Tennessee vaoey Authonty. post Dffice Box 2000, Decatur. Alabama 35609.2000 O. J. "lke" Zering Ue Vice President. Browns Ferry Nuclear Plant JUN Bt t993 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 50-260/93005 The enclosed report provides details concerning an event that resulted in a manual or automatic actuation of any engineered safety feature (ESF). This event was a result, of personnel error in that an individual did not include necessary precautions in a Modifications work plan to preclude an ESF actuation.

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

Sincerely, (i'~yrfA

0. J. Zeringue Enclosure cc: See page 2 4 BOI'Vv 9306290202 930621 zp r

PDR ADOCK 05000260 S 'PDR

II A, U.S. Nuclear Regulatory Commission JUN 3i 1953 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

1 HRC Form 366 NUCLEAR REGULATORY COttGSSION Approved OHB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

FACILITY'NAME (1) iDOCKET NUMBER (2) i P w F 1 N (4) ESF Actuation Resulting From A n'ITLE Lifted Neutral Lead On A HSIV Solenoid Circuit.

V T Y P T T I I I . I I SEQUENTIAL I IREVISIONI I I I FACILITY NAMES IDOCKET NUMBER(S)

T T I l I I

62 193 I I I I I I I 0

OPERATING I ITHIS REPORT IS SUBMITTED PURSUANT TO THE RE(UIREHENTS OF 10 CFR g:

HODE r m w'

I I H I20.402(b) l20.405(c) ]~(50.73(a)(2)(iv) !73.71(b)

POWER )20.405(a)(l)(i) )50.36(c)( 1) f '(50.73(a)(2)(v) (73.71(c)

LEVEL l20.405(a)(1)(ii) ]50.36(c)(2) ] )50.73(a)(2)(vii) )OTHER (Specify in

)20.405(a)( 1)(i ii ) ]50.73(a)(2)(i)(B)( [50.73(a)(2)(viii)(A) Abstract below and in

)20.405(a)( l)(iv) )50.73(a)(2)(ii) ) (50.73(a)(2)(viii)(B) Text, NRC Form 366A) v 1 TH NAME

) AREA CODE A HP IREPORTABLEI I I I IREPORTABLEI I I Y PNNT NF NP N F T D

' EXPECTED PP N T P I I f SUBHISSIOH I I I Y f 1 D I T 1 ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines) (16)

On May 20, 1993, at 0145 hours0.00168 days <br />0.0403 hours <br />2.397487e-4 weeks <br />5.51725e-5 months <br />, a Modifications electri.cian li.fted a jumper and the neutral lead of the power supply to an ammeter for the main steam isolation valve solenoid circuit. The neutral lead in a daisy-chain configuration was removed, which opened the circuits to several Division 1 relays. This resulted in a primary containment isolation system (PCIS) Division 1 actuation'. Thus, this event is reportable in accordance with 10 CFR'0.73(a)(2)(iv) as an event that resulted in a manual or automatic ESF actuation.

The root cause for this event is personnel error for failing to identify the impact for the removal of the neutral lead when preparing and reviewing the work plan. The work plan writer and independent qualifi.ed reviewer (IQR) did not consider that the procedural precaution for lifting the neutral lead from the power supply was necessary under the plant configuration at 'the time of the event.

Work plan writers and IQR will be trained on individual's responsibilities to the requirements of proper review criteria for Modifications work plans and the circumstances of this event. In addition, the BFN's Modifications Training Handbook, will be revised and work plan writers and IQRs will be trained on special precautions implementation.

NRC Form,366(6-89)

0 II l

NRC Form 366A U. . NUCLEAR 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)

I I I I SEQUENTIAL I IREVISIONI, I I I I

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

I. PLANT CONDITIONS Unit 2 was in a cold shutdown mode for the Unit 2, Cycle 6 refueling outage.

Units 1 and 3 were shutdown and defueled.

II. DESCRIPTION OF EVENT On May 19, 1993, at 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br />, the Field Supervisor for a work plan to remove ammeters and jumpers from main steam isolation valve (MSIV) [ISV]

solenoid circuits reviewed the work plan to initiate a clearance request.

The supervisor noted that a field change was written to leave the, positive lead of the power supply to an ammeter which was scheduled to be replaced with a resister and test jacks. He understood the field change was written as such to avoid lifting a wire that could open a circuit to other equipment. Since the neutral lead was not addressed in the field change, the supervisor did not consider any negative consequences for lifting the neutral lead during the Modifications. Following the 2300 hour0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br /> shift turnover, the Unit 2 Operator was notified by Modifications personnel that the work plan to remove the ammeters was about to commence.

On May 20, 1993, at 0145 hours0.00168 days <br />0.0403 hours <br />2.397487e-4 weeks <br />5.51725e-5 months <br />, a Modifications electrician lifted a jumper and the neutral lead from terminal block BB-97 which supplied power to an ammeter for a MSIV solenoid circuit. The neutral lead in a daisy-chain configuration was removed, which opened the circuits to several Division 1 relays [RLY]. This resulted in a Primary Containment Isolation System (PCIS) Division 1 actuation [JM]. These relays controlled Group 1, 2, 3, 6, and 8 valves. Group 3 and 8 valves were previously closed and, therefore, did not actuate during this event. The Unit 2 inboard Main Steam Line [SB] Drain Valves in Group,l closed. The inboard Shutdown Cooling [BO] suction and discharge valves in Group 2 closed (this. system was not in service at the time of this event). Also, the Pressure Suppression Chamber [BT] suction valve in Group 2 closed. In Group 6, the Reactor Zone [VA] and the Refuel Zone [VG] Ventilation Systems isolated, the Standby Gas Treatment System [BH] initiated, and the Control Room Emergency Ventilation [VI] initiated. All systems and components responded as expected.

At 0228 hours0.00264 days <br />0.0633 hours <br />3.769841e-4 weeks <br />8.6754e-5 months <br /> on May 20, 1993, Operations personnel returned ESF systems and components to standby readiness with the exception of the Reactor Zone Ventilation. At 0240 hours0.00278 days <br />0.0667 hours <br />3.968254e-4 weeks <br />9.132e-5 months <br />, Operations then allowed the resumption ofto the work plan. At 0640 hours0.00741 days <br />0.178 hours <br />0.00106 weeks <br />2.4352e-4 months <br />, the Reactor Zone Ventilation was returned service.

NRC Form 366(6-89)

Ol NRC Form 366A (6-09)

U.. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER) t Approved OMB No. 3150-'0104 Expires 4/30/92 TEXT CONTINUATION (2)

FACILITY NAME (1) IDOCKET NUMBER I I I I SEQUENTIAL I IREVISIONI I I I, I Browns Ferry Uni t 2 I A I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)

Lifting of the neutral lead opened the circuits of several Division 1 relays and subsequently resulted in a PCIS Division 1 actuation. This PCIS actuation is reportable in accordance with 10 CFR 50.73(a)(2)(iv) as an event that resulted in a manual or automatic actuation of any Engineered Safety Feature (ESF).

B. n t t t t t t t None.

C. t A t May 20, 1993 at 0145 CST Modifications electrician lifted the neutral lead and a PCIS Division 1 actuation occurred.

May 20, 1993 at 0228 CST Except for the Reactor Zone Venti.lation-, Operations personnel returned ESF systems and components to standby readiness.

May 20, 1993 at 0400 CST A four-hour report was made to the NRC in accordance with 10 CFR 50.72(a)(2)(ii).

May 20, 1993 at 0640 CST Reactor Zone Ventilation returned to service.

D. th t r None.

This event was immedi.ately known to the Unit 2 *Operator at 0145 hours0.00168 days <br />0.0403 hours <br />2.397487e-4 weeks <br />5.51725e-5 months <br /> when ESF systems actuated and control room alarms indicating the actuation had occurred.

None.

G.

Groups 1, 2,= 3, 6, and 8 PCIS Division 1 actuation initiated as expec ed.

NRC Form 366(6-89)

II NRC Form 366A U.. NUCLEAR REGULATORY CONMISSION Approved ONB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) IDOCKET. NUNBER (2)

I I I I SEQUENTIAL I IREVISIONI I I I I Browns Ferry Uni t 2 I I I I I 4

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

III. CAUSE OF THE EVENT A.

The immediate cause for the event was the lifting of the neutral lead on the power supply to the ammeter for the MSIV solenoid circuit. This lifted neutral lead opened several relay circuits that resulted in the ESF actuation.

II- Rm~~IIaa =

The root cause for this event was determined to be personnel error for failing to identify the impact for the removal of the neutral lead when preparing and reviewing the work plan. The work plan writer and independent qualified reviewer (IQR) did not consider that the procedural precaution for lifting the neutral lead from the power supply was necessary under the present plant configuration at the time of this event.

Nevertheless, the Site Standard Practice for plant Modifications and design change control requires the work plan writer and the independent qualified reviewer to identify and review for necessary precautions and insert the necessary precautions at the appropriate steps in the work plan.

C.

The Field Supervisor did not take the appropriate .steps required to evaluate the impact of lifting the neutral lead of the power supply to the ammeter for the MSIV solenoid circuit when writing the clearance request.

IV. ANALYSIS OF THE EVENT At the time of the event, the MSIV was not required for plant safety because Unit 2 was in a cold shutdown mode for the Unit 2, Cycle 6 refueling outage.

Since all equipment performed as designed during the event, the inadvertent actuation of several ESF components did not adversely affect the health and safety of the public.

V. CORRECTIVE ACTIONS A. tv t Operations personnel stopped work on the work plan and investigated the cause of the event with the cognizant engineer. Alarms were reset and PCIS systems and components were returned to a standby readiness status except the Reactor Zone Ventilation.

NRC Form 366(6-89)

II NRC Form 366A (6-89)

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

I /SEQUENTIAL 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)

B. v t t Work plan writers and IQRs will be trained on individual's responsibilities to the requirements of a site standard practice for proper review criteria for Modifications work plans and the circumstances of this event.

2. The BFN s Modifications Training Handbook, will be revised and work plan writers and IQRs will be trained on special precautions implementation to heighten the awareness of Modifications personnel on the need to include the necessary precautions on future work plans.

VI. ADDITIONAL INFORMATION None.

B.

TVA reviewed previous reported events to find if similarpast events had occurred and if so, why corrective actions had been unsuccessful in preventing this event. Two previous events were identified (1) LER 260/91009 involved an ESF actuation resulting from personnel error in that

.personnel failed to adequately assess the impact of a missing relay on the MSIV isolation logic. Plant personnel were trained to consider related aspects of a temporary configuration when evaluating work activities for impact of plant equipment. This training was not provided to Modifications personnel as a corrective action. If this training had been provided to Modifications personnel this event might not have occurred.

(2) LER 260/90003 involved an ESF actuation when a power supply fuse to a main steam line radiation monitor was removed from the circuit. This event was a result of personnel error in that Operations personnel failed to perform and adequate review of the clearance request prior to its implementation. Although LER 260/93005 also involved the main steam system, Operations personnel did properly review the clearance request.

Therefore, corrective actions in LER 260/90003 would not have precluded the 260/93005 event.

NRC Form 366(6-89)

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

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

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

VII. COMMIIMRTS

1. Work plan writers and IQRs will be trained on individual's responsibilities to the requirements of a site standard practice for proper review criteria for Modifications work plans and the circumstances of this event by Jul'y 21, 1993.

2. The BFN's Modifications Training Handbook, will be revised and work plan writers and IQRs will be trained on special precautions 'implementation to hei'ghten the awareness of Modifications personnel on the need to include the necessary precautions on future work plans by July 21, 1993.

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

NRC Form 366(6-89)