ML17328A853

LER 90-013-00:on 901215,during Tech Spec Surveillance,Plant Battery Declared Inoperable When Single Cell Voltage Decreased Below Test Limit.Caused by Improper Setpoint. Setpoints Verified & Corrected as needed.W/910111 Ltr

ML17328A853
Person / Time
Site:	Cook
Issue date:	01/11/1991
From:	Blind A, Carteaux P INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-013-01, LER-90-13-1, NUDOCS 9101150352
Download: ML17328A853 (8)

Text

i CCELERATED DISTRIBUTION DEMONSTRATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) t~

ACCESSION NBR:9101150352 DOC.DATE: 91/01/11 NOTARIZED: NO DOCKET FACIL:50-316 Donald C. Cook Nuclear Power Plant, Unit 2, Indiana & 05000316 AUTH. NAME AUTHOR AFFILIATION

'CARTEAUX,P.F. Indiana Michigan Power Co. (formerly-Indiana & Michigan Ele BLIND,A.A. Indiana Michigan Power Co. (formerly Indiana & Michigan Ele RECIP.NAME RECIPIENT AFFILIATION R

SUBJECT:

LER 90-013-00:on 901215,during Tech Spec surveillance, plant battery declared inoperable when single cell voltage

,decreased below test limit.Caused by improper setpoint. D Setpoints verified & corrected as needed.W/910111 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR I ENCL TITLE: 50.73/50.9 Licensee Event Report (LER),incident Rpt, etc. L SIZE:

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-1 LA 1 1 PD3-1 PD 1 1 D COLBURN,T. 1 1 INTERNAL: ACNW 2 2 AEOD/DOA 1 1 AEOD/DS P/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB SD 1 1 NRR/DST/SICB 7E 1 1 S LBSD1 1 1 NRR/DST/SRXB 8E 1 1 REG ILE 02 1 1 RES/DSIR/EIB 1 1 E 01 1 1 EXTERNAL EG&G BRYCE E J ~ H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 D

D NO1 E. TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE O'ASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOihl PI-37 (EXT. 20079) TO ELlb IINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUP,IENTS YOU DON'T NEED!

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

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1 I

lndiany Michiqan Power Company "

Cook Nuclear Plant Otte Cook Place Bndgman. Ml 49106 616 465 5901 INDIANA NICHIGAN POWER January 11, 1991 United States Nuclear Regulatory Commission Document Control Desk Rockville, Maryland 20852 Operating Licenses DPR-75 Docket No. 50-316 Document Control Manager:

In accordance with the criteria established by 10 CFR 50.73 entitled Licensee Event Re ortin S stem the following report is being submitted:

90-013-00 Sincerely, A

A.A.

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Blind Plant Manager AAB:sb Attachment C'.H. Williams, Jr.

A.B. Davis, Region III M.P. Alexich P.A. Barrett J.E. Borggren R.F. Kroeger B. Walters Ft. Wayne NRC Resident Inspector T. Colburn NRC J.G. Keppler M.R. Padgett G. Charnoff, Esp.

Dottie Sherman, ANI Library D. Hahn INPO S.J. Brewer/B.P. Lauzau B.A. Svensson

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NRC FOAL) 365 U$ . NUCLFAR REGULATORY COMMISSION (6$ 9) APPAOVEO OMB NO. 31500)OC r.c EXPIRES: cl30/92 ESTIMATED BUAOEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST( 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THf. RECORDS AND REPORTS MANAGE'MENTBRANCH IP$ 30l. U.S. NUCLEAR REGULATOAY COMMISSION. WASHINGTON, DC 20555, ANO TO THE PAPERWOAK Rf DUCTION PROJECT (3150010C), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, OC 20503.

FACILITY NAME ll) DOCKET NUMBER (21 PA E D. C. Cook Nuclear Plant Unit 2 0 5 a a 0 316 >oFp Reactor Protection System Actuation While Performing a TS Required Shutdown Due to a Decreased Plant Battery Cell Voltage EVENT DATE (5) LKA NUMSEA IS) REtORT DATE 17) OTHER FACILITIES INVOLVED ISI YEAR ccNS sEQUENTIAL 1'A OK OAY YEAR FACII.ITYNAMES DOCKET NUMBER(SI MONTH OAY YEAR NUMOP.A R MONTH 0 5 0 0 0 1 2 15 90 90 0 1 3 0 00 111 91 0 5 0 0 0 THIS REtORT IS SUBMITTED PURSUANT T0 THE REQUIREMENTS OF 10 CFR (It (Chere one ormolr ol the Iollerrlnfl (11 OPERATING MOOK (9) ] 20A02(bl 20.405(cl 50.73(e(C(l(lr) 73.71(II)

POWEA 20AOB(o) II)(9 SOM(c) (I I 50.73(r) (2)( ~ ) 73.71(cl LEYEL 1 p p 20AOB(el(11(III SOM(cl(2) 50 73(el(2l(FBI OTHER ISbocttt in Abc ttect below erne In Trrt, FIAC fohn 20AOS(ol(1 l(IN) X 50.734)(2)(l) 50.734) (2) (r(II)(AI 34BAI 20AOB (o I( 11(lel 50.734)(21(9) 50.734)(2)(rlIII(~ I 20A054)(1)(c) 50,734)(2) I IU) 50.73(e) 11) lrl LICENSKE CONTACT fOR THIS LER 111)

NAME TELEPHONE NUMBER AREA COD'E P. F. Carteaux Safety and Assessment Superintendent 61 64'.6 5- 590 1 f

COMtLKTE ONE LINE fOll EACH COMtONENT AILUAE DESCAISED IN THIS REPORT (13)

Pv COMPONENT MANUFAC. EPOATABLE P r .CAUSE SYSTEM COMPONENT MANUFAC- EPOATABL CAUSE SYSTEM TURER TO NPRDS TURER TO NPROS Hgk c'.,r, n.;r, SUttLEMENTAL AEPOAT EXtECTEO lll) EXPECTED MONTH DAY YEAR SUSMISSIOII DATE (15)

YfS IIIyrt, complete EXPECTED SUBMISSIOIV DATE) NO ABSTRACT ILimit to tr00 torcrt, I.e., rootorimetelv Iiltern tinpl>corer teprwritten linrtl (14)

On December 15, 1990, at 0840 hours0.00972 days <br />0.233 hours <br />0.00139 weeks <br />3.1962e-4 months <br /> during a Technical Specification (TS) Surveillance, the 2-AB plant battery was declared inoperable when a single cell's voltage decreased below a test limit. Efforts taken to restore the cell voltage were unsuccessful and a reactor shutdown was initiated. During the shutdown at approximately 35 percent rated thermal power, a reactor protection system actuation occurred due to a turbine trip from an unnecessary actuation of the Anticipated Transient Without Scram Mitigation System Actuation Circuitry (AMSAC). All equipment performed as expected and there were no component failures following the trip.

The reactor entered Mode 5 at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on 12-16-90 to exit the battery TS Action Statement and the battery cell of concern was removed from service via a jumper. A proposed TS Amendment is being prepared to request changing the surveillance to align with industry standards and conform to Standard TS.

The AMSAC actuation occurred due to an improper setpoint.

All AMSAC input setpoints were verified and corrected as needed.

NRC Form 355 (5$ 9)

NRC FORM 36SA (669)

LICENSEE EVENT REPORT ILER)

US. NUCLEAR REGULATORY COMMISSION e APPROVEO OMB NO 3150d)OE EXP IR ES: S)30IQ2 ESTIMATEO BUROEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REOUESTI 50.0 HRS. FORWARD COMMENTS REGAROING BUROEN ESTIMATE TO THE R'ECOROS TEXT CONTINUATION ANO REPORTS MANAGEMENT BRANCH )F630), U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON, OC 20555, ANO TO THE PAPERWORK REDUCTION PROJECT {3)50dlOSI. OFFICE OF MANAGEMENTANO BUDGET, WASHINGTON, OC 20503.

FACILITY NAME 11I OOCKET NUMBER 12) LER NUMBER IS) PAGE 13)

YEAR SEOUENTIAL REVISION NUMEER NUMEER D. C. Cook Nuclear Plant - Unit 2 0 5 0 0 0 3 1 6 0 1 3 0 0 0 2 OF 0 TEXT llfmare specs is er)arrsd, IISS eddiaarNJ AIRC %%dnII 36SA's) I)T)

Condition Prior to Occurrence Unit 2 in Mode 1 at 100 percent Rated Thermal Power (RTP).

Descri tion of Event On December 15, 1990, at 0840 hours0.00972 days <br />0.233 hours <br />0.00139 weeks <br />3.1962e-4 months <br /> during a 92 day Technical Specification (TS) surveillance, the 2-AB plant battery (EIIS/EJ-BTRY) was declared inoperable when a single cell's voltage decreased by more than 0.05 volts from the original acceptance test value. The 2-AB plant battery consists of 116 connected cells.

The TS 92-day surveillance requirements for the D.C. electrical power distribution system states, in part, the following:

The voltage of each connected cell is greater than or equal to 2.10 volts under float charge and has not decreased more than 0.05 volts from the value observed during the original acceptance test.

All 2-AB battery cells were greater than the minimum 2.10 volt limit and all but one cell remained within the 0.05 volt decrease limit. Efforts taken to restore the cell voltage were unsuccessful and a conservative decision was made not to attempt repairs while at power. At 1245 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.737225e-4 months <br /> a reactor shutdown was initiated in accordance with the TS Action Statement.

During the shutdown, at approximately 35 percent rated thermal power, a reaction protection system (EIIS/JE) actuation (reactor trip) occurred due to a turbine trip. The turbine trip resulted from the unnecessary actuation of the Anticipated Transient Without Scram (ATWS) Mitigation System Actuation Circuity (AMSAC). The AMSAC system is designed to protect against an ATHS coincident with a loss of main feedwater. It automatically trips the Main Turbine, initiates a feedwater conservation signal and starts all auxiliary feedwater pumps if less than 25 percent of full main feedwater flow is sensed (three out of four steam generator coincidence) with Turbine Impulse Pressure (TIP) greater than 40 percent of full power (P-20) or within 6 minutes after a TIP channel (1 out of 2 coincidence) is reduced below permissive P-20.

Following the AMSAC actuation the turbine trip/reactor trip sequence [turbine (EIIS/TA-TRB) trip, automatic starting of the motor-driven and turbine-driven auxiliary feedwater pumps (EIIS/BA-P), opening of the reactor trip breakers (EIIS/JE-BKR), insertion of reactor control rods and feedwater isolation (EIIS/JB)] the Operations Department personnel immediately performed Emergency NRC F onII 366A 1869)

NAC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION 1649) APPROVED DMS NO. 31504104 EXPIRES) 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFOAMATION COLLECTION REQUEST: SOJ) HRS. FORWARD COMMENTS REQARDINQ BURDEN ESTIMATE TO THE RECOADS TEXT CONTINUATION ANO AEPOATS MANAGEMENT BRANCH IP.530), U.S. NUCLEAR REGULATOAY COMMISSION, WASHINGTON, OC 20555, ANO TO THE PAPERWORK REDUCTION PROJECT 13)504)04). OFFICE OF MANAGEMENTANO BUDGET,WASHINGTON, OC 20503 FACILITYNAME III DOCKET NUMBER 12) LEA NUMSEA Ib) PAGE 13)

YEAR INg~

SEGVSNTIAL REVISION NVMSSR NUM 4)I D. C. Cook Nuclear Plant - Unit 2 0 5 0 0 0 3 ] 9 0 0 1 3 000 3 OF 0 TEXT //I mar soscsis ssoossIL oss sIA/io'oss/HRC Fons 366l'4/ I)))

Operating Procedures (EOP) to verify proper response of the automatic protection system and to assess plant conditions for indicated appropriate recovery actions. All equipment performed as expected and there were no component failures following the trip.

The reactor entered Mode 5 (cold shutdown) at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on 12-16-90 to exit the 2-AB plant battery TS Action Statement.

Cause of the Event The Technical Specification requirement that. the voltage must not decrease more than 0.05 volts from the acceptance test. is an overly restrictive condition for battery operability and is not mentioned in:

Regulatory Guide 1.129, "Maintenance, Testing, and Replacement of Large Lead Storage Batteries for Nuclear Power Plants" Westinghouse Standardized Technical Specifications Manufacturer's Installation and Operating Instructions Manual (C&D Power Systems, N12-800)

IEEE Standards 450-1975, 1980 and 1987 The cause of the AMSAC actuation was that the 25 percent feedwater flow setpoints were set at approximately 35 percent feedwater flow (a conservative value for actuation of AMSAC). From the initial system implementation until the 1990 refueling outage, . the feedwater flow setpoints were 25 percent of design flow. During this last refueling outage (ending in November) the feedwater flow values were changed,'rom the percent design value originally used, to an actual flow value to more accurately reflect plant operating conditions. The setpoints inserted were mistakenly set at approximately 35 percent flow due to a misinterpretation of the setpoint control document's calculated voltage input location. This feedwater flow setpoint in coincidence with a power decrease rate greater than approximately 0.8 percent of RTP per minute resulted in the AMSAC actuation. The plant is designed for a two percent per minute decrease with all systems in automatic in this operating range.

NRC Fons 366A IBBS)

NRC FORM 388A

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~

0 LICENSEE EVENT REPORT (LER)

US. NUCLEAR REGULATORY COMMISSION APPAOVEO OMB NO. 31500104 EXPIRES: r/30192 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION AEOUESTI 50JI HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION ANO REPORTS MANAGEMENT BRANCH IP830). U.S. NUCLEAR REGULATOAY COMMISSION, WASHINGTON, OC 20555. AND TO THE PAPERWORK REDUCTION PROJECT I3)S00104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME 111 DOCKET NUMBER 121 LER NUMBER 051 PAGE IS)

VEAR SEOVCNTIAL +AS REVISION NVMSSR W~< NVMSSR D. C. Cook'Nuclear Plant Unit 2 0 6 0 0 0 3 1 9 0 0 1 3 0 0 4 OF 0 4 TEXT Illmoo rpoco Ir NRRrnd, orr aRIIoaW NRC hvm SSSA'r) IIT)

Anal sis of Event This event, is being reported in accordance with 10 CFR 50.73(A)(2)(X) and 10 CFR 50.73(A)(2)(IV) as an event that resulted in the completion of a Technical Specification required shutdown and an unplanned automatic actuation of the engineered safety features, including the reactor protection system, respectively.

The Technical Specification Limiting Condition of Operation and the associated Action Statement were complied with and the automatic protection responses, including reactor trip and its associated actuations, were verified to have functioned properly as a result of the reactor trip signal. Based on the above, that the event did not constitute an unreviewed safety question as it is concluded defined in 10 CFR 50.59 nor did safety of the public.

it adversely impact the health and Corrective Action The 2-AB battery was removed from service for repairs electrically removing (via jumpers) the cell of concern, which'ncluded as well as, another cell that experienced .voltages approaching the 0.05 differential voltage limit.

A proposed Technical Specification Amendment is being prepared to request changing the related 92-day surveillance to that found in Standard Technical Specifications which would remove the requirement of having cells within 0.05 of the their individual acceptance test.

Methods to safely jumper battery cells in Nodes 1-4 while complying with the current TS are being researched.

All setpoints in the AMSAC system were verified and the inappropriate setpoints on the feedwater flow portion of the circuit were corrected. Similar setpoint corrections were made to the Unit 1 circuit (which was in a refueling outage and never operated with the inappropriate setpoints).

Failed Com onents None Previous Similar Events None NAC Form 388A (689)