ML18039A820

LER 99-004-00:on 990625,facility Core Spray Divisions I & II Inoperable at Same Time Due to Personnel Error.Electrical Supply Breaker to Core Spray Division II Pump 3B Returned to Normal Racked in Position

ML18039A820
Person / Time
Site:	Browns Ferry
Issue date:	07/26/1999
From:	Donald Norwood TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18039A819	List: ML18039A818 ML18039A820
References
LER-99-004-02, NUDOCS 9908030241
Download: ML18039A820 (12)

Text

NRC FORM 366 (6-)99BI llCENSEE EVENT REPORT (I.ER)

U.S..NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3160-0104

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EKP)RES Estimated burden per response to comply with th)s mandatory informagon cosecgon request: 50 hrs. Reported )essons learned are ncorporated )nto the Ecenslng process and fed back to )ndustry. Forward burden esgmate to the Records Management Branch (TA F33), V.S. Nucfear os)so)soot eganring

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Regu)story Commission. Washington,'C 205554XOI, and to the Paperwork Reduction Project (3t500104). 05ce ol Management and Budget, (See reverse for required number of Washington. OC 20503, lf an information cogecUon does not display a digits/characters for each block) currengy varrd OMB control number. the NRC may not conduct or sponsor, and a person d not requ)red to respond to. the hformaUon FAClUTY NAME IS) DOCKET NUMSER (2) PAOE IS)

Browns Ferry Nuclear Plant - Unit 3 05000296 1 of 6 TrTLE la)

Inoperability of Two Divisions of the Unit 3 Core Spray System Due to Personnel Error EVENT DATE (5I LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (6)

MONTH DAY YEAR YEAR sEOUENT)AL REv)S)ON MONTH DAY YEAR FACIUTY NAME DOCKET NUMBER NUMBER NUMBER NA NA 06 25 1999 1999 - 004- 00'7 26 999 NA DOCKET NUMBER NA OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR Ii: (Check one or moro) (11)

MODE le) 20.2201(b) 20.2203(a)(2)(v) X 50.73(a)(2)(i) So 73(a) (2) (vln

)

POWER 20. 2203(a) (1) 20.2203(a)(3)(i) 50.73(a) (2) (ii) S0.73(a)(2)(x)

I.EVEL (10) 100 20.2203la) l2) II) 20.2203 la) (3) (ii) 50.73(a)(2)(iii) 73.71 20.2203(a) (2)(ii) 20.2203(a)(4) 50.73(a)(2)(iv) OTHER 20.2203(a) (2) (iii) 50.36(c)(1). 50.73(a)(2)(v) Spec)fy In Abstract below or in NRC Form 366A

20. 2203(al(2) (iv) 50.36(c)(2) 50.73(a)(2) (vil)

LICENSEE CONTACT FOR THIS LER (12)

TELEPHONE NUMBER (Inorudo Area Coda)

Donald Norwood, Sr. Project Manager (256) 729-7905 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

SYSTEM COMPONENT MANUFACTURER REPORTABLE TO CAUSE COMPONENT, MANUFACTURER REPORTABLE NPRDS TO NPRDS gj'$$ ;a

'A%? ii ..";"i:

SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH 0AY YEAR YES X NO SUBMISSION (If yes, complete EXPECTED SUBMiSSION DATE). DATE (15)

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

On June 25, 1999, at 1352 hours0.0156 days <br />0.376 hours <br />0.00224 weeks <br />5.14436e-4 months <br /> Central Daylight Time (CDT), Unit 3 Core Spray (CSI Divisions I and II were technically inoperable at the same time. This condition was the result of personnel error during performance of the surveillance test, Backup Control Panel Testing (3-SR-3.3.3.2.1(75 I)] for CS Division I. During performance of the surveillance test, the electrical supply breaker for CS Division II pump 3B was racked out instead of the breaker for CS Division I pump 3C as required by the surveillance test. Prior to the event, CS Division I pump 3A had been made inoperable per the surveillance test. This action had made CS Division I inoperable. At the time of the event, pump 3A had been returned to a condition where it was available (and hence CS Division I was available), and would have functioned if required. However, CS Division I was still inoperable per plant Technical Specifications. The operations'taff recognized that two divisions of CS were inoperable and appropriately entered LCO 3.0.3. At 1418 hours0.0164 days <br />0.394 hours <br />0.00234 weeks <br />5.39549e-4 months <br /> CDT, CS Division II was returned.to operable status and LCO 3.0.3 exited. The root cause of this event was personne) error.

Prior to, and during the event, all other Emergency Core Cooling Systems (ECCS) were operable. Accordingly, there was no significant reduction in the degree of protection provided to the public health and safety. Furthermore, the safety of the plant, its personnel, and the public was not compromised.

This report is submitted pursuant to 10 CFR 50.73 (a)(2)(i)(B), as any operation or condition prohibited by the plant's Technical Specifications.

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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION IS-I 998i L[CENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 1 DOCKET LER NUMBER 6 PAGE 3 YEAR SEOUENTIAL REVISION NUMBER 2of6 Browns Ferry Nuclear Plant - Unit 3 05000296 1999 004 00 TEXT fifmore spaceis required, use additional copies of NRC Form 366A/ (17)

PLANT CONDITION{S)

At the time of the event, Unit 1 was shutdown and defueled.:Unit 2 was in Mode 1 at 100 percent reactor power, approximately 3456 megawatts thermal. Unit 3 was in mode 1 at 100 percent reactor power, approximately 3456 megawatts thermal.

DESCRIPTION OF EVENT A. Event:

On June 25, 1999 at 1145 hours0.0133 days <br />0.318 hours <br />0.00189 weeks <br />4.356725e-4 months <br /> Central Daylight Time (CD7) surveillance test Backup Control Panel Testing [3-SR-3.3.3.2.1(75 I)] for Core Spray (CS) [BM] Division I was started. At 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br /> CDT, CS pump 3A [P] was made inoperable per the surveillance test by racking out its electrical supply breaker [BKR]. This action made CS Division I inoperable. At 1349 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.132945e-4 months <br /> CDT, the electrical supply breaker for CS pump 3A was returned to its normal racked in position.

At 1351 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.140555e-4 months <br /> CDT, CS pump 3A was declared available but stilt not operable per Technical Specifications.

3-SR-3.3.3.2.1(75 I) then required racking out the electrical supply breaker [BKR] for CS Division I pump 3C [P]. However, at 1352 hours0.0156 days <br />0.376 hours <br />0.00224 weeks <br />5.14436e-4 months <br /> CDT, the Assistant Unit Operator {AUO) [utility, non-licensed] performing the breaker manipulations racked out the electrical supply breaker

[BKR] for CS Division II pump 3B [P] instead. This action resulted in CS Division II being inoperable. In conjunction with the technically inoperable CS Division I, this resulted fn a condition prohibited by the plant's Technical Specifications. Limiting Condition for Operation (LCO) 3.0.3 was entered at that time.

The electrical supply breaker to the CS Division II pump 3B was returned to its normal racked in position. CS Division II was tested for operability per 3-OI-75. CS Division II was declared operable at 1418 hours0.0164 days <br />0.394 hours <br />0.00234 weeks <br />5.39549e-4 months <br /> CDT and LCO 3.0.3 was exited at that time.

B. Ino erable Structures Com onents orS stemsthatContributedtothe Event:

None.

C. Dates and A roximate Times of Ma or Occurrences:

June 25, 1999, 1145 hours0.0133 days <br />0.318 hours <br />0.00189 weeks <br />4.356725e-4 months <br /> CDT Surveillance 3-SR-3.3;3.2.1{75 I), Backup Control Panel Testing for Core Spray Division I was started.

June 25, 1999, 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br /> CDT Breaker for Core Spray Division I pump 3A racked out per Surveillance 3-SR-3.3.3.2.1{75 I); Core Spray pump 3A, and hence Core Spray system Division I, declared inoperable.

Ik 41 NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 1 DocKET LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION NUMBER 3 of 6 Browns Ferry Nuclear Plant - Unit 3 05000296 1999 004 00 TEXT (i! more space is required, use additional copies of NRC Form 366Ai I17)

June 25, 1999, 1349 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.132945e-4 months <br /> CDT Breaker for Core Spray Division I pump 3A returned to the normal racked in position.

June 25, 1999, 1351 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.140555e-4 months <br /> CDT Core Spray pump 3A, and hence Core Spray Division I available for. service per maintenance rule.

June 25, 1999, 1352 hours0.0156 days <br />0.376 hours <br />0.00224 weeks <br />5.14436e-4 months <br /> CDT Breaker for Core Spray Division II pump 3B racked out. Surveillance 3-SR-3.3.3.2.1(75 I) specified breaker for Core Spray Division I pump 3C to be racked out. This action caused Division II of the Core Spray system to be inoperable.

June 25, 1999, -1400 hours CDT With both Divisions of the Core Spray system inoperable, LCO 3.0.3 was entered. Unit 3 SRO directed that Core Spray Division II pumps be run per Operating Instruction (Ol) 75 to allow Core Spray Division II to be declared operable.

June 25, 1999, 1416 hours0.0164 days <br />0.393 hours <br />0.00234 weeks <br />5.38788e-4 months <br /> CDT Core Spray Division II pumps 3B and 3D placed in service per 3-OI-75, Section 8.12.

June 25, 1999, 1418 hours0.0164 days <br />0.394 hours <br />0.00234 weeks <br />5.39549e-4 months <br /> CDT Core Spray Division II pumps 3B and 3D secured. Core Spray Division II declared operable. LCO 3.0.3 exited.

D. Other S stems or Seconda Functions Affected None.

E. Method of Discove During performance of Surveillance 3-SR-3.3.3.2.1(75 I), Unit 3 Control Room Operators [utility, licensed] noticed that expected annunciators for CS Division I pump 3C had not alarmed, but annunciators for CS Division II pump 3B that were not expected to be in alarm status had in fact alarmed.

F. 0 erator Actions At 1352 hours0.0156 days <br />0.376 hours <br />0.00224 weeks <br />5.14436e-4 months <br /> CDT, the Assistant Unit Operator (AUO) [utility, non-licensed] performing the breaker manipulations racked out the electrical supply breaker for CS Division II pump 3B instead of the breaker required by the surveillance (CS Division I pump 3C breaker). This was a cognitive error in that the AUO had mentally incorrectly associated CS pump 3B with Division I instead of CS pump 3C. This error was contrary to the approved surveillance. There were no unusual characteristics of the work location (e.g., heat, noise) that directly contributed to this error.

NRC FORM 366 {6-199B)

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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION I6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITYNAME 1 DOCKET LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL NUMBER 4 of 6 Browns Ferry Nuclear Plant - Unit 3 05000296 1999 004 00 TEXT llfmore spaceis required, use additional copies of ftiRC Form 366A/ f17I G. Safet S stem Res onses None.

III. CAUSE OF THE EVENT A. Immediate Cause The immediate cause of this event was the racking out of the incorrect CS pump electrical supply breaker (CS pump 3B breaker instead of CS pump 3C breaker).

B, Root Cause The root cause of the event was personnel error. The wrong Core Spray pump breaker was removed due to a lack of effective self-checking with no peer check performed.

C. Contributin Factors The two 4 KV electrical board rooms on Unit 3 have both Division I and Division II boards in the same room (Shutdown (S/D) Boards [ECBD] 3A and 3C in one, S/D boards 3B and 3D ln the other). The boards in each room are separated by an automatically closing fire door within the.

same room. The lack of visual separation of these rooms contributed to the mind-set that boards 3A and 3C were in the same division.

The 3B Emergency Core Cooling System (ECCS) pumps are on 3C 4 KV S/D board (Division II) and 3C pumps are on 38 4KV S/D board (Division I).

The pre-job brief was inadequate for the evolution.

Failure of management observations to detect problems with effective self-checking.

IV. ANALYSIS OF THE EVENT Prior to performance of the surveillance test, a pre-job brief was performed. However, no formal prejob briefing package was written. Specific steps of the procedure were not pointed out, including no reference made to the fact that the Unit 3 S/D Board rooms have two divisions in each room.

This coupled with the fact that CS pump 3B is fed from. the 3C 4KV S/D Board and CS pump 3C is fed from the 3B 4KV S/D board led to an incorrect association of CS pumps to their divisional assignments by the individual performing the operator actions in the surveillance test. This incorrect association.was that the CS pumps 3A and 3B were Division I pumps instead of the correct CS pumps 3A and 3C.

V. ASSESSMENT OF THE SAFETY CONSEQUENCES The purpose of the Core Spray system is to protect against over-heating the fuel in the event. of a Loss of Coolant Accident (LOCA). There are two independent, redundant, 100% capacity Core S ra Divisions Division I and Division ll . CoreS ra in con'unction with other ECCS Automatic NRC FORM 366 I6-1998)

0 NRO FDRM 3eeA U.S. NUCLEAR REGULATORY COMMISSION (6-1998I LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 1 DOCKET LER NUMSER 6 PAGE 3 YEAR SEQUENTIAl REVISION NUMBER Browns Ferry Nuclear Plant - Unit 3 05000296 1999 004 00 TEXT (Ii more space is required, use additional copies ol iVRC Farm 366A J 117)

'V. ASSESSMENT OF THE SAFETY CONSEQUENCES (continued)

Depressurization System (ADS) [SB], Low Pressure Coolant Injection (LPCI) [BO], and High Pressure Coolant Injection (HPCI) [BJ]) provide adequate core cooling over the entire LOCA break spectrum.

At the time of this event, CS Division I was inoperable per Technical Specifications. However, CS Division I was in a condition where it was available had It been called upon to function. CS Division II was made Inoperable for only a short period of time (minutes) prior to it being recognized that the wrong electrical supply breaker had been racked out. Upon recognizing this, the electrical supply breaker to CS Division II pump 38 was returned to the normal racked in position. At this time, CS Division II was then available had it been called upon to function. Within 26 minutes after the wrong electrical supply breaker was racked out, CS Division II was tested and declared operational per Technical Specifications. Prior to, and throughout this short duration event, all other ECCS remained o perable.

Accordingly, there was no significant reduction in the degree of protection provided to the public health and safety. Furthermore, the safety of the plant, its personnel, and the public was not compromised.

VI. CORRECTIVE ACTIONS A. Immediate Corrective Actions The electrical supply breaker to CS Division II pump 38 was returned to its normal racked in position. The Unit 3 SRO directed that CS Division II pumps be placed in service to demonstrate operability. CS Division II successfully demonstrated operability and at 141 &'hours CDT CS Division II was declared operable.

B. Corrective Actions to Prevent Recurrence Future pre-job briefings will include warnings about this specific human factors issue.

The Operations'raining Department will include this event in the "Plant Events simulator scenario training for Licensed operator requalification training and in the required reading program of non-licensed personnel.'perations'anagement will establish a self-assessment that mill focus on management observations to detect problems with effective self-checking.

'eer checks on actions associated with breaker operations, placement of jumpers, pulling fuses, or other actions which cause irreversible conditions on equipment will be required for surveillances and other critical tests.

initial licensed and non-iicensed operator training lesson plans will be revised to

'pplicable include issues associated with this event.'VA does not consider these corrective actions regulatory commitments. The completion of these items will be tracked in TVA's Corrective Action Pro ram.

NRc FoRM See 18-19981

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NRC FORM 366A U.S. NUCLEAR REGULATORY I6 1998)

LICENSEE EVENT'REPORT. (LER) COMMISSION'ACILITY TEXT CONTINUATION NAME 1 DOCKET LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION NUMBER col 6 Browns Ferry Nuclear Plant - Unit.3 05000296 1999 004 00 TEXT (If more space is required, use additional copies of iVRC Form 366AJ I17I VII. ADDITIONALINFORMATION.

A. Failed Com onents None.

B. Previous LERs on Similar Events LER 50-296/97004, issued on May'14, 1997,,was written to document the unplanned manual start of Emergency Diesel Generator (EDG) 3D as a result of personnel error during surveillance testing; C. Additional Information None D. Safe S stem Functional Failure:

This event did not result in a safety system functional failure in accordance with NEI 99-02.

VIII. COMMITMENTS None.

NRC FORM 366 (6-1998I

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