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| | issue date = 06/20/1996 | | | issue date = 06/20/1996 |
| | title = LER 96-002-00:on 960504,critical Bus SM-8 Lost Power When Supply Breaker 3-8 Tripped.Caused by Personnel Error. Operators Counselled & Procedures revised.W/960620 Ltr | | | title = LER 96-002-00:on 960504,critical Bus SM-8 Lost Power When Supply Breaker 3-8 Tripped.Caused by Personnel Error. Operators Counselled & Procedures revised.W/960620 Ltr |
| | author name = BEMIS P R, PFITZER B | | | author name = Bemis P, Pfitzer B |
| | author affiliation = WASHINGTON PUBLIC POWER SUPPLY SYSTEM | | | author affiliation = WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| | addressee name = | | | addressee name = |
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| {{#Wiki_filter:CATEGORYREGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)ACCESSIOH NBR:9606260184 DOC.DATE: 96/06/20 NOTARIZED: | | {{#Wiki_filter:CATEGORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) |
| NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH.NAME AUTHOR AFFILIATION PFITZER,B. | | ACCESSIOH NBR:9606260184 DOC.DATE: 96/06/20 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION PFITZER,B. Washington Public Power Supply System BEMIS,P.R. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION |
| Washington Public Power Supply System BEMIS,P.R. | |
| Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION | |
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| ==SUBJECT:== | | ==SUBJECT:== |
| LER 96-002-00:on 960504,critical bus SM-8 lost power when Supply breaker 3-8 tripped.Caused by personnel error.Operators counselled s procedures revised.W/960620 ltr.DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR I ENCL (SIEE: 5 TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.NOTES: T E INTERNAL: RECIPIENT ID CODE/NAME PD4-2 PD ACRS AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DSIR/EIB COPIES LTTR ENCL 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 RECIPIENT ID CODE/NAME COLBURN,T AEOD D AB E C TER R~~B NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN4 FILE 01 COPIES LTTR ENCL 1 1 2 2 1 1 1 1 1~1 1~1 1 1 1 1 1 R D EXTERNAL: L ST LOBBY WARD NOAC MURPHY,G.A NRC PDR 1 1 1 1 1 1 LITCO BRYCE,J H NOAC POOREEW.NUDOCS FULL TXT 2 2 1 1 1 1 M N NOTE TO ALL"RIDS" RECIPIENTS: | | LER 96-002-00:on 960504,critical bus SM-8 lost power when Supply breaker 3-8 tripped. Caused by personnel error. |
| PLEASE HELP US TO REDUCE WASTE!CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5D-5(EXT.415-2083)TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED'.FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 26 ENCL 26 WASH I.'iGTO.'v PUBLIC POWER SUPPLY SYSTEM PO.Box 968~3000 George 11rrshirrgton 11'ar~Richland, 11raslrington 99352-0968 | | Operators counselled s procedures revised.W/960620 ltr. |
| ~(509)372-5000 June 20, 1996 G02-96-124 Docket No.50-397 Document Control Desk U.S.Nuclear Regulatory Commission Washington, D.C.20555 Gentlemen: | | DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR I ENCL ( SIEE: |
| | TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc. |
| | 5 T E |
| | NOTES: |
| | RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD4-2 PD 1 1 COLBURN,T 1 1 R |
| | INTERNAL: ACRS 1 1 AEOD D AB 2 2 |
| | ~~ |
| | AEOD/SPD/RRAB 1 1 E C TER 1 1 NRR/DE/ECGB 1 1 R~~B 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 RES/DSIR/EIB 1 1 RGN4 FILE 01 1 1 D |
| | EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 2 2 NOAC MURPHY,G.A 1 1 NOAC POOREEW. 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 M |
| | N NOTE TO ALL "RIDS" RECIPIENTS: |
| | PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5D-5(EXT. 415-2083) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED'. |
| | FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 26 ENCL 26 |
| | |
| | WASH I.'iGTO.'v PUBLIC POWER SUPPLY SYSTEM PO. Box 968 ~ 3000 George 11rrshirrgton 11'ar ~ Richland, 11raslrington 99352-0968 ~ (509) 372-5000 June 20, 1996 G02-96-124 Docket No. 50-397 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen: |
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| ==Subject:== | | ==Subject:== |
| NUCLEAR PLANT WNP-2, OPERATING LICENSE NPF-21, VOLUNTARY LICENSEE EVENT REPORT NO.96-002-00 Transmitted herewith is voluntary Licensee Event Report No.96-002-00 for WNP-2.This event is not reportable under 10CFR50.72 or 10CFR50.73. | | NUCLEAR PLANT WNP-2, OPERATING LICENSE NPF-21, VOLUNTARYLICENSEE EVENT REPORT NO. 96-002-00 Transmitted herewith is voluntary Licensee Event Report No. 96-002-00 for WNP-2. This event is not reportable under 10CFR50.72 or 10CFR50.73. This report is submitted voluntarily for information. |
| This report is submitted voluntarily for information. | | Should you have any questions or desire additional information regarding this matter, please call me or Ms. Lourdes Fernandez at (509) 377-4147. |
| Should you have any questions or desire additional information regarding this matter, please call me or Ms.Lourdes Fernandez at (509)377-4147.Res tfully, P.R Bemis (Mail Drop PE20)Vice President, Nuclear Operations Enclosure cc: LJ Callan, NRC RIV TG Colburn, NRR KE Perkins, Jr., NRC RIV, WCFO NS Reynolds, Winston&Strawn NRC Sr.Resident Inspector, MD927N (2)INPO Records Center-Atlanta, GA DL Williams, BPA, MD399 9606260i84 960620 PDR ADOCK 05000397 8 PDR 0 | | Res tfully, P. R Bemis (Mail Drop PE20) |
| LICENSEE EVENT REPORT (LER)TACAI TV NAME (I I Washington Nuclear Plant-Unit 2 DocxET MA(TER (I(0 5 0 0 0 3 9 7 1 (4 TITLE(e(INADVERTENT LOSS OF POWER TO CRITICAL BUS AND EDG START DUE TO CLEARANCE ORDER RESTORATION ACTIVITY (ER NVMSER (el 0 IIRR TACAITKS e(VOLV(D ee DOCKET (ARISTA(et 05 04 96 96 0 0 2 0 0 06 20 96 N/A 0 5 0 0 0 5 0 0 OtERAT SIC MODE (SI tOWER LEV(L (I(e*(20.402(b)(20.405(s)(l)(i) 20.405(s)(1)(ii)Q 0 Q (20.405(e)(l)(iii)
| | Vice President, Nuclear Operations Enclosure cc: LJ Callan, NRC RIV NRC Sr. Resident Inspector, MD927N (2) |
| I 20.405(s)(l)(iv) 20.405(s)(1)(v)
| | TG Colburn, NRR INPO Records Center - Atlanta, GA KE Perkins, Jr., NRC RIV, WCFO DL Williams, BPA, MD399 NS Reynolds, Winston & Strawn 9606260i84 960620 PDR ADOCK 05000397 8 PDR |
| (20.405c ((50.36(c)(l)
| | |
| )50.36(c)(2)
| | 0 LICENSEE EVENT REPORT (LER) |
| )(50.73(s)(2)(i) | | TACAI TV NAME (I I DocxET MA(TER (I( |
| )(50.73(s)(2)(ii)
| | Washington Nuclear Plant Unit 2 0 5 0 0 0 3 9 7 1 ( 4 TITLE(e( INADVERTENT LOSS OF POWER TO CRITICAL BUS AND EDG START DUE TO CLEARANCE ORDER RESTORATION ACTIVITY (ER NVMSER (el 0 IIRR TACAITKS e(VOLV(D ee DOCKET (ARISTA(et N/A 0 5 0 0 05 04 96 96 0 0 2 0 0 06 20 96 0 5 0 0 OtERATSIC Uee R(PORT IS SUOMI(TEO tVRSVANT TO THE REOUIR(MENTS Oc 'lo CIR: II II MODE (SI |
| I I 50.73(s)(2)(NI)
| | * ( 20.402(b) ( 20.405c ( 50.73(e)(2)(iv) I I 73.71(b) |
| Uc(NTEE CONTACT SOR Ties LER I It(Uee R(PORT IS SUOMI(TEO tVRSVANT TO THE REOUIR(MENTS Oc'lo CIR: II II (50.73(e)(2)(iv)
| | ( 20.405(s)(l)(i) ( ( 50.36(c)(l) ) 50.73(s)(2)(v) ) 73.71(c) tOWER LEV(L 20.405(s) (1) (ii) 50.36(c)(2) 50.73(e)(2)(vrl) X OTHER (Specify (n Abstrect be(ow end |
| )50.73(s)(2)(v) | | ) ( ( ( |
| (50.73(e)(2)(vrl)
| | (I(e in Text, NRC Form 366A) |
| )50.73(e)(2)(vii)A 50.73(s)(2)(viii)
| | Q 0 Q ( 20.405(e)(l)(iii) ) ( 50.73(s)(2)(i) ) 50.73(e)(2)(vii)A I 20.405(s)(l)(iv) ) ( 50.73(s)(2)(ii) 50.73(s)(2)(viii) B 20.405(s)(1)(v) I I 50.73(s)(2)(NI) ) 50.73(SH2)(x) |
| B)50.73(SH2)(x)
| | Uc(NTEE CONTACT SOR Ties LER I It( |
| I I 73.71(b))73.71(c)(X (OTHER (Specify (n Abstrect be(ow end in Text, NRC Form 366A)I(((tIIONE NUMI(R Bill Pfitzer, Licensing Engineer COMt(ETE OtC LSC IOR EACH COMt(HANT TALVRE DESCRR(D IN TITS R(toRT ((el 509 377-2419 MAIREAD.TURLR R(toRTAS(E TO MVDS MAIREAD.TVR(R R(PORTA(LE TO MV(DS SVttLEMENTAL REtoel EXTEC(m ((4(YES (i)yes, complete EXPECTED SUBM(SSION DATE)ABSTRACI')6)(X(ko EXPECTED SUBMISSION DATE (15)On May 4, 1996 at 0142, with the reactor defueled, critical bus SM-8 lost power when supply breaker 3-8 tripped.As a result, emergency diesel generator (EDG)2 auto started and the backup transformer automatically provided power to SM-8.Detailed investigation into this event determined the cause to be accidental opening of the non-critical bus SM-3 potential transformer (PT)fuse compartment by an equipment operator (EO)performing restoration activities for a clearance order.Event notification was made to the NRC pursuant to the requirements of 10 CFR 50.72(b)(2) as an Engineered Safety Feature (ESF)actuation. | | I(((tIIONE NUMI(R Bill Pfitzer, Licensing Engineer 509 377-2419 COMt(ETE OtC LSC IOR EACH COMt(HANT TALVRE DESCRR(D IN TITS R(toRT ((el MAIREAD. R(toRTAS(E MAIREAD. R(PORTA(LE TURLR TO MVDS TVR(R TO MV(DS SVttLEMENTAL REtoel EXTEC(m ((4( EXPECTED SUBMISSION YES (i) yes, complete EXPECTED SUBM(SSION DATE) (X( ko DATE (15) |
| This notification was subsequently retracted after a detailed review of the event and the actuated equipment. | | ABSTRACI')6) |
| The WNP-2 FSAR does not specify the EDGs as an Engineered Safety Feature.This LER is submitted on a voluntary basis.*-Defueled LICENS EVENT REPORT (LER)TEXT CO INUATlON TEXT (17)Washington Nuclear Plant-Unit 2 0 5 0 0 0 3 9 7 96 stovcM lal stvMM st 002 0 0 2" 4 Even De cri i n On May 4, 1996 at 0142, with the reactor defueled, the control room received alarms indicating an undervoltage condition on non-critical bus[BU]SM-3.Breaker[BKR]3-8 tripped due to the undervoltage condition causing a loss of power to critical bus SM-8.As a result, EDG-2[DG]auto started, the backup transformer | | On May 4, 1996 at 0142, with the reactor defueled, critical bus SM-8 lost power when supply breaker 3-8 tripped. As a result, emergency diesel generator (EDG) 2 auto started and the backup transformer automatically provided power to SM-8. Detailed investigation into this event determined the cause to be accidental opening of the non-critical bus SM-3 potential transformer (PT) fuse compartment by an equipment operator (EO) performing restoration activities for a clearance order. |
| [XFMR]automatically provided power to the SM-8 bus, and residual heat removal pump 2B (RHR-P-2B) | | Event notification was made to the NRC pursuant to the requirements of 10 CFR 50.72(b)(2) as an Engineered Safety Feature (ESF) actuation. This notification was subsequently retracted after a detailed review of the event and the actuated equipment. The WNP-2 FSAR does not specify the EDGs as an Engineered Safety Feature. This LER is submitted on a voluntary basis. |
| [BO,P], which was operating in the fuel pool cooling[DA]assist mode, experienced a temporary loss of power.Plant restoration activities were completed at approximately 0306.Immediate orrective Action Immediately after the incident, Operations management suspended ongoing clearance order restoration activities and secured the area around the SM-3 auxiliary electrical cubicle to support investigation activities. | | * - Defueled |
| A Problem Evaluation Request (PER)was initiated. | | |
| RHR-P-2B was returned to service in the fuel pool cooling assist mode after approximately 45 minutes.Plant electrical lineup and equipment restoration was completed at approximately 0306.Further Evalua ion During the Incident Review Board (IRB)investigation, the EO reported that he had opened and closed the door of the SM-3 auxiliary electrical cubicle in preparation for restoration of a clearance order associated with transformer TR-S.The EO stated that after looking inside the cubicle he shut the door and then heard relays chatter.He speculated he had jarred the relays while closing the cabinet door.Event evaluation, including further interviews of the EO involved, determined the following: | | LICENS EVENT REPORT (LER) TEXT CO INUATlON stovcM lal stvMMst Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 96 002 0 0 2 " 4 TEXT (17) |
| ~Momentary opening of the SM-3 bus PT fuse compartment, which is a~d'scent to the compartment specified by the clearance, would have caused all the auto actions which occurred during this event.Both fuse compartments are located inside the SM-3 auxiliary electrical cubicle which must be opened to view the compartments. | | Even De cri i n On May 4, 1996 at 0142, with the reactor defueled, the control room received alarms indicating an undervoltage condition on non-critical bus [BU] SM-3. Breaker [BKR] 3-8 tripped due to the undervoltage condition causing a loss of power to critical bus SM-8. As a result, EDG-2 [DG] |
| The compartment doors utilize a protective feature which disconnects the fuses as the compartment door is opened. | | auto started, the backup transformer [XFMR] automatically provided power to the SM-8 bus, and residual heat removal pump 2B (RHR-P-2B) [BO,P], which was operating in the fuel pool cooling |
| LICENSEE EVENT REPORT (LER)TEXT CONTINUATION Sf QUCMNl NUM SOI RKVISKIH HUMOR TEXT (l7)Washington Nuclear Plant-Unit 2 05 0 0 0 3 9 7 96 002 0 0 3 oF 4 The door latch for the SM-3 bus PT fuse compartment was found in the 11:30 (just closed)position rather than the 9:00 (fully closed)position as expected.PT fuse disconnects of this type can be easily opened and re-closed in approximately 1-2 seconds.~The control room alarm printer"SM-3 UNDERVOLTAGE" indication took about 2 seconds to return to normal.~In an effort to reproduce an inadvertent relay operation, the SM-3 auxiliary electrical cubicle door was repeatedly slammed.No operation of SM-3 undervoltage relays due to mechanical jarring or bumping was observed.~The maximum length of time for an HFA undervoltage relay to trip and return to normal due to mechanical jarring or bumping is approximately 40 to 50 milliseconds. | | [DA] assist mode, experienced a temporary loss of power. Plant restoration activities were completed at approximately 0306. |
| In this case, the relay which must actuate after the undervoltage relay to effect opening of breaker 3-8 requires the undervoltage signal to be approximately | | Immediate orrective Action Immediately after the incident, Operations management suspended ongoing clearance order restoration activities and secured the area around the SM-3 auxiliary electrical cubicle to support investigation activities. |
| | A Problem Evaluation Request (PER) was initiated. |
| | RHR-P-2B was returned to service in the fuel pool cooling assist mode after approximately 45 minutes. |
| | Plant electrical lineup and equipment restoration was completed at approximately 0306. |
| | Further Evalua ion During the Incident Review Board (IRB) investigation, the EO reported that he had opened and closed the door of the SM-3 auxiliary electrical cubicle in preparation for restoration of a clearance order associated with transformer TR-S. The EO stated that after looking inside the cubicle he shut the door and then heard relays chatter. He speculated he had jarred the relays while closing the cabinet door. Event evaluation, including further interviews of the EO involved, determined the following: |
| | ~ Momentary opening of the SM-3 bus PT fuse compartment, which is a~d'scent to the compartment specified by the clearance, would have caused all the auto actions which occurred during this event. Both fuse compartments are located inside the SM-3 auxiliary electrical cubicle which must be opened to view the compartments. The compartment doors utilize a protective feature which disconnects the fuses as the compartment door is opened. |
| | |
| | LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Sf QUCMNl RKVISKIH NUMSOI HUMOR Washington Nuclear Plant - Unit 2 05 0 0 0 3 9 7 96 002 0 0 3 oF 4 TEXT (l7) |
| | The door latch for the SM-3 bus PT fuse compartment was found in the 11:30 (just closed) position rather than the 9:00 (fully closed) position as expected. |
| | PT fuse disconnects of this type can be easily opened and re-closed in approximately 1-2 seconds. |
| | ~ The control room alarm printer "SM-3 UNDERVOLTAGE" indication took about 2 seconds to return to normal. |
| | ~ In an effort to reproduce an inadvertent relay operation, the SM-3 auxiliary electrical cubicle door was repeatedly slammed. No operation of SM-3 undervoltage relays due to mechanical jarring or bumping was observed. |
| | ~ The maximum length of time for an HFA undervoltage relay to trip and return to normal due to mechanical jarring or bumping is approximately 40 to 50 milliseconds. In this case, the relay which must actuate after the undervoltage relay to effect opening of breaker 3-8 requires the undervoltage signal to be approximately 1.0 second in duration. |
| | The physical evidence listed above led the IRB to postulate three possible causes for the SM-3 undervoltagb condition. These potential causes were: |
| | ~ Slamming the SM-3 auxiliary electrical cubicle door which jarred the undervoltage relays of SM-3 causing breaker 3-8 to trip. |
| | ~ Dirty contacts on the SM-3 bus PT fuse stabs which caused poor contact, an undervoltage condition and tripping of breaker 3-8. |
| | ~ Opening of the SM-3 bus PT fuse compartment which caused an undervoltage condition and tripping of breaker 3-8. |
| | After careful consideration, Operations management concluded the cause of the event was momentary opening of the SM-3 bus PT fuse compartment by the EO. It was further concluded that the EO operated the SM-3 bus PT fuse compartment and, upon realizing his error, hastily reclosed the PT compartment leaving the compartment in the abnormal condition found by the IRB investigators. This conclusion is further supported by the information recorded on the control room alarm printer and the information obtained during testing of the components involved. |
| | This LER is submitted on a voluntary basis. |
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| | 0 LICENS EVENT REPORT (LER) TEXT CO INUATION SfOUCMtNL ROI5ON |
| in duration.The physical evidence listed above led the IRB to postulate three possible causes for the SM-3 undervoltagb condition.
| | ~MA NVM80l Washington Nuclear Plant - Unit 2 05 0 0 0 3 9 7 96 002 0 0 4 o" 4 TEXT u7) |
| These potential causes were:~Slamming the SM-3 auxiliary electrical cubicle door which jarred the undervoltage relays of SM-3 causing breaker 3-8 to trip.~Dirty contacts on the SM-3 bus PT fuse stabs which caused poor contact, an undervoltage condition and tripping of breaker 3-8.~Opening of the SM-3 bus PT fuse compartment which caused an undervoltage condition and tripping of breaker 3-8.After careful consideration, Operations management concluded the cause of the event was momentary opening of the SM-3 bus PT fuse compartment by the EO.It was further concluded that the EO operated the SM-3 bus PT fuse compartment and, upon realizing his error, hastily reclosed the PT compartment leaving the compartment in the abnormal condition found by the IRB investigators.
| | Root au e The root cause for this event is personnel error. The SM-3 bus PT fuse compartment was inadvertently opened, causing an SM-3 undervoltage signal. |
| This conclusion is further supported by the information recorded on the control room alarm printer and the information obtained during testing of the components involved.This LER is submitted on a voluntary basis.
| | A contributing cause was inadequate pre-job brief. The Production Reactor Operator (RO) and Senior Reactor Operator (SRO) did not address the potential adverse consequences of operation of the bus PT fuse compartment. |
| 0 LICENS EVENT REPORT (LER)TEXT CO INUATION TEXT u7)Washington Nuclear Plant-Unit 2 05 0 0 0 3 9 7 96 SfOUCMtNL~MA 002 ROI5ON NVM80l 0 0 4 o" 4 Root au e The root cause for this event is personnel error.The SM-3 bus PT fuse compartment was inadvertently opened, causing an SM-3 undervoltage signal.A contributing cause was inadequate pre-job brief.The Production Reactor Operator (RO)and Senior Reactor Operator (SRO)did not address the potential adverse consequences of operation of the bus PT fuse compartment. | |
| An additional contributing cause was failure to follow the procedure requirements to identify clearance order steps for PT fuse restoration as requiring simultaneous verification. | | An additional contributing cause was failure to follow the procedure requirements to identify clearance order steps for PT fuse restoration as requiring simultaneous verification. |
| Further orrective Action Personnel action appropriate to the circumstances was taken with the EO.The Production RO and SRO were counseled concerning the necessity of performing adequate pre-job briefs prior to performance of critical clearance activities. | | Further orrective Action Personnel action appropriate to the circumstances was taken with the EO. |
| The procedures/instructions governing clearance order preparation will be revised to ensure the need for simultaneous verification is noted on the required clearance order steps.Assessment f fe Conse uence The safety consequences of this event are minimal.The reactor was defueled at the time this event occurred.Expected automatic actions occurred including auto starting of EDG-2 and re-energization of SM-8 from the backup transformer. | | The Production RO and SRO were counseled concerning the necessity of performing adequate pre-job briefs prior to performance of critical clearance activities. |
| RHR-P-2B, which was operating in the fuel pool cooling assist mode, tripped as a result of the loss of power but was restored after approximately 45 minutes.Estimated time to boil at the time of this event was 52 hours.Previous Similar Events Previous LERs documenting personnel error resulting in actuation of safety-related equipment are as follows: LER 96-001 involved inadvertent ESF actuations due to tripping of a temporary power supply to IN-3 by outage electricians. | | The procedures/instructions governing clearance order preparation will be revised to ensure the need for simultaneous verification is noted on the required clearance order steps. |
| | Assessment f fe Conse uence The safety consequences of this event are minimal. The reactor was defueled at the time this event occurred. Expected automatic actions occurred including auto starting of EDG-2 and re-energization of SM-8 from the backup transformer. RHR-P-2B, which was operating in the fuel pool cooling assist mode, tripped as a result of the loss of power but was restored after approximately 45 minutes. Estimated time to boil at the time of this event was 52 hours. |
| | Previous Similar Events Previous LERs documenting personnel error resulting in actuation of safety-related equipment are as follows: |
| | LER 96-001 involved inadvertent ESF actuations due to tripping of a temporary power supply to IN-3 by outage electricians. |
| LER 95-002 involved Operations personnel operating the wrong lever during a main turbine test resulting in turbine trip and reactor scram.}} | | LER 95-002 involved Operations personnel operating the wrong lever during a main turbine test resulting in turbine trip and reactor scram.}} |
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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML17292B7421999-07-20020 July 1999 LER 99-001-00:on 990628,ESF Signal Closed All Eight MSIVs While Plant Was Shutdown.Caused by Failure of Relay RPS-RLY-K10D.Subject Relay Was Replaced & Tested on 990630. with 990720 Ltr ML17292B4451998-10-27027 October 1998 LER 98-012-01:on 980715,failure to Comply with Requirements of TS SR 3.8.4.7 Was Noted.Caused by Inadequate Work Practices.Training Session Was Held with Personnel.With 981027 Ltr ML17284A7561998-09-0303 September 1998 LER 98-013-00:on 980805,ESF Actuations Were Noted Due to Deenergization of Vital Electrical Bus SM-8.Caused by Inadequate Direction in Troubleshooting Plan.Will Conduct Training for Engineering Personnel.With 980903 Ltr ML17284A7571998-09-0202 September 1998 LER 98-014-00:on 980807,completion of TS 3.8.1.F Required Shutdown Due to Inoperability of EDG-2 Was Noted.Caused by Degraded Voltage Regulator for DG-2.Replaced Voltage Regulator & Associated Scrs.With 980902 Ltr ML17284A7551998-09-0202 September 1998 LER 98-015-00:on 980808,discovered Reactor Coolant Pressure Boundary Leak During Shutdown Conditions.Caused by Leakage from Socket Weld (Fwb 63) on Elbow Connection.Failed Piping Connection Was Replaced.With 980902 Ltr ML17284A7311998-08-17017 August 1998 LER 98-012-00:on 980716,determined That 24-month SR 3.8.4.7 Had Not Been Fulfilled within Specified Frequency.Caused by Inadequate Work Practices.License Requested & Received Enforcement Discretion Re Battery Svc test.W/980817 Ltr ML17284A7121998-07-23023 July 1998 LER 98-006-01:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of 10CFR50,App R Calculations for High Impedance Faults.Caused by Inadequate Work Practices.Implemented Procedural Changes ML17284A6951998-07-17017 July 1998 LER 98-011-00:on 980617,ECCS Pump Room Flooding Was Noted Due to FP Sys Pipe Break.Caused by Inadequate Design of FP Sys.Detailed Review of FP Sys Design Was Conducted. W/980717 Ltr ML17284A6961998-07-15015 July 1998 LER 98-010-00:on 980615,TS Required Shutdown Due to Inoperability of TIP Sys Isolation Valve Was Noted.Caused by Improper Installation of TIP Tubing.Reattached Affected Tubing & Inspected Other TIP tubing.W/980715 Ltr ML17284A6731998-07-0101 July 1998 LER 98-009-00:on 980606,nuclear Steam Supply Shutoff Sys Group 3 & 4 Isolations During Testing Was Noted.Caused by Procedural Deficiency.Counseled Individuals Involved in preparation.W/980701 Ltr ML17284A6651998-06-24024 June 1998 LER 98-007-00:on 980530,inadvertent Full Scram & Division 1 ECCS Injection Was Noted.Caused by Failure to Meet Mgt Work Practice Expectation When Encountering Deficient Procedure. Incident Review Board Convened to Review event.W/980624 Ltr ML17284A6641998-06-24024 June 1998 LER 98-008-00:on 980531,inadvertent Full Scram During RPV Leak Testing in Mode 4 Was Noted.Caused by Change in Mgt Techniques.Revised Procedures to Take Into Account Addl Water Head in Pressure Sensing lines.W/980624 Ltr ML17284A6631998-06-19019 June 1998 LER 98-006-00:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of App R Calculations for High Impedance Fault Analysis.Caused Indeterminate. Implemented Procedural Changes Involving Operator Action ML17284A6551998-06-0404 June 1998 LER 98-005-00:on 980506,potential for Failure of RHR Sys Valve to Close on Isolation Signal Was Noted.Caused by Design Deficiency.Caution Tag Was Placed on RHR-V-40 Control Switch to Inform Plant Operators of limitation.W/980604 Ltr ML17284A6421998-06-0101 June 1998 LER 98-004-00:on 980502,determined That Primary Containment Penetration Overcurrent Protection Does Not Meet Reg Guide 1.63 Requirements.Caused by Inadequate Design Changes. Installed Addl Fuse in RHR-MO-9 circuit.W/980601 Ltr ML17292B3281998-04-0909 April 1998 LER 98-002-00:on 980311,reactor Scram & Plant Transient Occurred,Due to Failed Closed Main Steam Isolation Valve. Caused by Loss of Pneumatic Actuating Supply Pressure. Problem Evaluation Request Written for Failure of MS-V-22D ML17292B3291998-04-0909 April 1998 LER 98-003-00:on 980311,WNP-2 Experienced SCRAM Signal as Result of Low Rpv.Caused by Less than post-SCRAM Operational Strategy for Resetting SCRAM Signal in Conditions.Changes in post-SCRAM Operational Strategy implemented.W/980409 Ltr ML17292B2661998-03-0404 March 1998 LER 98-001-00:on 980203,automatic Start of HPCS EDG Was Noted.Caused by Operator Error.Operations Crew Stabilized Plant at Approximately 75% Reactor Power & Investigation of Event Was initiated.W/980304 Ltr ML17292B1111997-11-10010 November 1997 LER 97-011-00:on 971010,HPCS Battery Charger Failed.Caused by Failure of a Phase Firing Control Circuit Board Due to Aging During 7 Yrs of Use.Hpcs Sys Was Immediately Declared inoperable.W/971110 Ltr ML17292B1151997-11-0707 November 1997 LER 97-010-00:on 970906,discovered That TS SR 3.4.5.1 for Identified Portion of RCS Total Leakage Would Not Be Able to Perform within Time Limits of SR 3.0.2.Caused by Inadequate Methods.Method of Meeting SR 3.4.5.1 Established ML17292B0641997-09-24024 September 1997 LER 97-004-01:on 970327,plant Operators Manually Scrammed Reactor as Required by TS Due to Indication of Entry Into Region a of power-to-flow Map.Caused by Inadequate Attention to Detail.Established Event Evaluation teams.W/970924 Ltr ML17292B0241997-08-18018 August 1997 LER 97-009-00:on 970717,discovered Error in Recently Performed Inservice Testing procedure,OSP-TIP/IST-R701. Caused by Procedure Inadequacy.Plant Procedure OSP/TIP/IST-R701 Will Be changed.W/970818 Ltr ML17292B0291997-08-15015 August 1997 LER 97-008-00:on 970716,wire Seal Used to Lock Containment Instrument Air Pressure Control valve,CIA-PCV-2B,found Not Intact.Cause of Misadjustment of CIA-PCV-2B Unknown.Event Will Be Communicated to Plant employees.W/970815 Ltr ML17292B0201997-08-15015 August 1997 LER 97-S01-00:on 970718,failure to Take Compensatory Measure for Inoperative Microwave Security Zone Occurred. Caused by Personnel Error.Training Will Be Conducted W/ Appropriate Members of Security force.W/970815 Ltr ML17292A9481997-07-23023 July 1997 LER 97-007-00:on 970611,voluntary Rept of Automatic Start of DG-1 & DG-2 Was Experienced.Caused by Undervoltage Condition on Electrical Busses SM-7 & SM-8.Circulating Water Pump CW-P-1C Control Switch Placed in pull-to-lock.W/970723 Ltr ML17292A9201997-06-26026 June 1997 LER 97-006-00:on 970527,non-performance of Surveillance Requirement 3.6.1.3.2 for Blind Fanges,Was Noted.Caused Because Misunderstanding of Intent of Specs.Added Five Structural Assemblies for SP.W/970626 Ltr ML17292A8331997-04-28028 April 1997 LER 97-004-00:on 970327,plant Operators Manually Scrammed Reactor as Required by TS Due to Entry Into Region a of power-to-flow Map Following Planned Trip of Single Mfp. Event Evaluation teams,established.W/970428 Ltr ML17292A8311997-04-28028 April 1997 LER 97-005-00:on 970327,valid Reactor Scram Signal Received Due to Low Water Level Condition During Preparations for SRV Testing.Caused by Risks & Consequences of Decisions Not Completely Identified.Restored Water level.W/970428 Ltr ML17292A8251997-04-21021 April 1997 LER 97-003-00:on 970320,notification of Noncompliance W/Ts as TS SRs for Response Time Testing Were Not Being Met for Specified Instrumentation in Rps,Pcis & Eccs.Requested Enforcement Discretion for One Time exemption.W/970421 Ltr ML17292A7431997-03-20020 March 1997 LER 97-002-00:on 970218,determined That Rod Block Monitor (RBM) Calibr Values Were Not Set IAW Tech Specs.Caused by Calibr Procedures Inadequacies.Revised & re-performed RBM Channel Calibr procedures.W/970330 Ltr ML17292A7401997-03-13013 March 1997 LER 97-001-00:on 970211,reactor Water Cleanup Sys Blowdown Flow Isolation Setpoint Was Slightly Above TS Allowable Valve Occurred Due to Calculation Error.Lds Fss LD-FS-15 LD-FS-16 Were Declared inoperable.W/970313 Ltr ML17292A6641997-01-22022 January 1997 LER 96-009-00:on 961220,miscalculation of Instantaneous Overcurrent Relay Settings Resulted in Inoperability of safety-related Equipment.Caused by Utilization of Inappropriate Design.Testing Was completed.W/970122 Ltr ML17292A6461997-01-0606 January 1997 LER 96-008-00:on 961205,failure to Comply with TS Action Requirement for Emergency Core Cooling Sys Actuation Instrumentation Occurred Due to Unidentified Inoperability Condition.Pmr initiated.W/970106 Ltr ML17292A6371996-12-19019 December 1996 LER 96-007-00:on 961122,electrical Breakers Were Not Seismically Qualified in Test/Disconnect Position.Circuit Breaker Mfg Did Not Consider Raced Out Breaker Position During Testing.Relocated Circuit breakers.W/961217 Ltr ML17292A4121996-08-0808 August 1996 LER 96-006-00:on 960709,average Power Range Monitor Rod Block Downscale Surveillance Not Performed Prior to Entry Into Mode 1.Caused by long-standing Misinterpretation of Requirements of Tss.Procedures revised.W/960808 Ltr ML17292A3801996-07-24024 July 1996 LER 96-004-00:on 960624,plant Was Manually Scrammed by Control Room Personnel Due to Reactor Water Level Transient Experienced During Testing of Digital Feedwater Sys.Caused by Programming Error.Sys Was corrected.W/960724 Ltr ML17292A3771996-07-24024 July 1996 LER 96-005-00:on 960624,determined Missed Surveillance Test Re Channel Check of Average Power Range Monitor.Caused by Inadequate Procedures.Revised Surveillance Procedure Re When APRM Checks Must Be performed.W/960724 Ltr ML17292A3641996-07-12012 July 1996 LER 96-003-00:on 960615,required Surveillance Test Not Performed When Required by TS 3.4.1.3.Caused by Inadequate Procedures.Implementing Surveillance Procedure & Reactor Plant Startup Procedures revised.W/960712 Ltr ML17292A3361996-06-20020 June 1996 LER 96-002-00:on 960504,critical Bus SM-8 Lost Power When Supply Breaker 3-8 Tripped.Caused by Personnel Error. Operators Counselled & Procedures revised.W/960620 Ltr ML17292A2861996-05-24024 May 1996 LER 96-001-00:on 960425,inadvertent ESF Actuations Occurred Due to Tripping of Temporary Power Supply to IN-3.Caused by Personnel Error.Operations Restored to IN-3 Loads & Reset ESF actuations.W/960524 Ltr ML17291B0891995-10-19019 October 1995 LER 95-011-00:on 950919,failed to Comply W/Ts SR for RCIC Sys Due to Analysis Deficiency That Resulted in Inadequate Surveillance Test Procedure.Surveillance Procedure Revised to Correct deficiency.W/951019 Ltr ML17291A9021995-07-0707 July 1995 LER 95-010-00:on 950609,HPCS DG Declared Inoperable Due to Discovery That TS Test Method Incomplete.Caused by Inadequate Testing Procedure.Test Procedure for HPCS DG Reviewed & Special Test Procedures written.W/950707 Ltr ML17291A9031995-07-0707 July 1995 LER 95-009-00:on 950607,inadvertent MSIV Closure Occurred During Surveillance Test Due to Poor Communication Between Test Team.Determined That MSIV Closure Not Valid Because Closure Not Triggered by Plant conditions.W/950707 Ltr ML17291A8501995-06-0808 June 1995 LER 95-006-01:on 950405,reactor Scram Occurred During Surveillance Testing Due to Protective Sys Relay Failure. Replaced Failed Relay Before Plant Startup ML17291A8101995-05-12012 May 1995 LER 95-008-00:on 940125,TS Wording Lead to Potential TS Violation.Caused by Lack of Clarity in Ts.Submitted Improved TS for Plant to Provide Addl clarity.W/950512 Ltr ML17291A7841995-05-0505 May 1995 LER 95-007-00:on 950222,emergency Diesel Start Occurred Due to Voltage Transient on BPA Grid.Confirmation Was Received at 17:51 H That Disturbance Had Originated in BPA Grid ML17291A7801995-05-0404 May 1995 LER 95-006-00:on 950405,main Turbine Trip Occurred During Performance of Surveillance Test Due to Protective Sys Relay Failed.Replaced Failed Relay Before Plant startup.W/950504 Ltr ML17291A7851995-05-0303 May 1995 LER 95-005-00:on 950222,inoperable IRM Had Been Relied Upon to Meet TS Requirements During Reactor Startup.Caused by Lack of Neutron Source to Test Instrumentation. Sys Knowledge Gained Will Be incorporated.W/950503 Ltr ML17291A7071995-03-25025 March 1995 LER 95-004-00:on 950226,malfunction in Main Turbine DEH Control Sys Caused All Four High Pressure Turbine Governor Valves to Rapidly Close.Caused by Blown Fuse.Suspected Faulty Circuit Card replaced.W/950325 Ltr ML17291A7011995-03-20020 March 1995 LER 95-002-00:on 950218,automatic Reactor Scram Occurred. Caused by Erroneous Positioning of Control During Performance of Scheduled Periodic Functional Test.Control repositioned.W/950320 Ltr 1999-07-20
[Table view] Category:RO)
MONTHYEARML17292B7421999-07-20020 July 1999 LER 99-001-00:on 990628,ESF Signal Closed All Eight MSIVs While Plant Was Shutdown.Caused by Failure of Relay RPS-RLY-K10D.Subject Relay Was Replaced & Tested on 990630. with 990720 Ltr ML17292B4451998-10-27027 October 1998 LER 98-012-01:on 980715,failure to Comply with Requirements of TS SR 3.8.4.7 Was Noted.Caused by Inadequate Work Practices.Training Session Was Held with Personnel.With 981027 Ltr ML17284A7561998-09-0303 September 1998 LER 98-013-00:on 980805,ESF Actuations Were Noted Due to Deenergization of Vital Electrical Bus SM-8.Caused by Inadequate Direction in Troubleshooting Plan.Will Conduct Training for Engineering Personnel.With 980903 Ltr ML17284A7571998-09-0202 September 1998 LER 98-014-00:on 980807,completion of TS 3.8.1.F Required Shutdown Due to Inoperability of EDG-2 Was Noted.Caused by Degraded Voltage Regulator for DG-2.Replaced Voltage Regulator & Associated Scrs.With 980902 Ltr ML17284A7551998-09-0202 September 1998 LER 98-015-00:on 980808,discovered Reactor Coolant Pressure Boundary Leak During Shutdown Conditions.Caused by Leakage from Socket Weld (Fwb 63) on Elbow Connection.Failed Piping Connection Was Replaced.With 980902 Ltr ML17284A7311998-08-17017 August 1998 LER 98-012-00:on 980716,determined That 24-month SR 3.8.4.7 Had Not Been Fulfilled within Specified Frequency.Caused by Inadequate Work Practices.License Requested & Received Enforcement Discretion Re Battery Svc test.W/980817 Ltr ML17284A7121998-07-23023 July 1998 LER 98-006-01:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of 10CFR50,App R Calculations for High Impedance Faults.Caused by Inadequate Work Practices.Implemented Procedural Changes ML17284A6951998-07-17017 July 1998 LER 98-011-00:on 980617,ECCS Pump Room Flooding Was Noted Due to FP Sys Pipe Break.Caused by Inadequate Design of FP Sys.Detailed Review of FP Sys Design Was Conducted. W/980717 Ltr ML17284A6961998-07-15015 July 1998 LER 98-010-00:on 980615,TS Required Shutdown Due to Inoperability of TIP Sys Isolation Valve Was Noted.Caused by Improper Installation of TIP Tubing.Reattached Affected Tubing & Inspected Other TIP tubing.W/980715 Ltr ML17284A6731998-07-0101 July 1998 LER 98-009-00:on 980606,nuclear Steam Supply Shutoff Sys Group 3 & 4 Isolations During Testing Was Noted.Caused by Procedural Deficiency.Counseled Individuals Involved in preparation.W/980701 Ltr ML17284A6651998-06-24024 June 1998 LER 98-007-00:on 980530,inadvertent Full Scram & Division 1 ECCS Injection Was Noted.Caused by Failure to Meet Mgt Work Practice Expectation When Encountering Deficient Procedure. Incident Review Board Convened to Review event.W/980624 Ltr ML17284A6641998-06-24024 June 1998 LER 98-008-00:on 980531,inadvertent Full Scram During RPV Leak Testing in Mode 4 Was Noted.Caused by Change in Mgt Techniques.Revised Procedures to Take Into Account Addl Water Head in Pressure Sensing lines.W/980624 Ltr ML17284A6631998-06-19019 June 1998 LER 98-006-00:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of App R Calculations for High Impedance Fault Analysis.Caused Indeterminate. Implemented Procedural Changes Involving Operator Action ML17284A6551998-06-0404 June 1998 LER 98-005-00:on 980506,potential for Failure of RHR Sys Valve to Close on Isolation Signal Was Noted.Caused by Design Deficiency.Caution Tag Was Placed on RHR-V-40 Control Switch to Inform Plant Operators of limitation.W/980604 Ltr ML17284A6421998-06-0101 June 1998 LER 98-004-00:on 980502,determined That Primary Containment Penetration Overcurrent Protection Does Not Meet Reg Guide 1.63 Requirements.Caused by Inadequate Design Changes. Installed Addl Fuse in RHR-MO-9 circuit.W/980601 Ltr ML17292B3281998-04-0909 April 1998 LER 98-002-00:on 980311,reactor Scram & Plant Transient Occurred,Due to Failed Closed Main Steam Isolation Valve. Caused by Loss of Pneumatic Actuating Supply Pressure. Problem Evaluation Request Written for Failure of MS-V-22D ML17292B3291998-04-0909 April 1998 LER 98-003-00:on 980311,WNP-2 Experienced SCRAM Signal as Result of Low Rpv.Caused by Less than post-SCRAM Operational Strategy for Resetting SCRAM Signal in Conditions.Changes in post-SCRAM Operational Strategy implemented.W/980409 Ltr ML17292B2661998-03-0404 March 1998 LER 98-001-00:on 980203,automatic Start of HPCS EDG Was Noted.Caused by Operator Error.Operations Crew Stabilized Plant at Approximately 75% Reactor Power & Investigation of Event Was initiated.W/980304 Ltr ML17292B1111997-11-10010 November 1997 LER 97-011-00:on 971010,HPCS Battery Charger Failed.Caused by Failure of a Phase Firing Control Circuit Board Due to Aging During 7 Yrs of Use.Hpcs Sys Was Immediately Declared inoperable.W/971110 Ltr ML17292B1151997-11-0707 November 1997 LER 97-010-00:on 970906,discovered That TS SR 3.4.5.1 for Identified Portion of RCS Total Leakage Would Not Be Able to Perform within Time Limits of SR 3.0.2.Caused by Inadequate Methods.Method of Meeting SR 3.4.5.1 Established ML17292B0641997-09-24024 September 1997 LER 97-004-01:on 970327,plant Operators Manually Scrammed Reactor as Required by TS Due to Indication of Entry Into Region a of power-to-flow Map.Caused by Inadequate Attention to Detail.Established Event Evaluation teams.W/970924 Ltr ML17292B0241997-08-18018 August 1997 LER 97-009-00:on 970717,discovered Error in Recently Performed Inservice Testing procedure,OSP-TIP/IST-R701. Caused by Procedure Inadequacy.Plant Procedure OSP/TIP/IST-R701 Will Be changed.W/970818 Ltr ML17292B0291997-08-15015 August 1997 LER 97-008-00:on 970716,wire Seal Used to Lock Containment Instrument Air Pressure Control valve,CIA-PCV-2B,found Not Intact.Cause of Misadjustment of CIA-PCV-2B Unknown.Event Will Be Communicated to Plant employees.W/970815 Ltr ML17292B0201997-08-15015 August 1997 LER 97-S01-00:on 970718,failure to Take Compensatory Measure for Inoperative Microwave Security Zone Occurred. Caused by Personnel Error.Training Will Be Conducted W/ Appropriate Members of Security force.W/970815 Ltr ML17292A9481997-07-23023 July 1997 LER 97-007-00:on 970611,voluntary Rept of Automatic Start of DG-1 & DG-2 Was Experienced.Caused by Undervoltage Condition on Electrical Busses SM-7 & SM-8.Circulating Water Pump CW-P-1C Control Switch Placed in pull-to-lock.W/970723 Ltr ML17292A9201997-06-26026 June 1997 LER 97-006-00:on 970527,non-performance of Surveillance Requirement 3.6.1.3.2 for Blind Fanges,Was Noted.Caused Because Misunderstanding of Intent of Specs.Added Five Structural Assemblies for SP.W/970626 Ltr ML17292A8331997-04-28028 April 1997 LER 97-004-00:on 970327,plant Operators Manually Scrammed Reactor as Required by TS Due to Entry Into Region a of power-to-flow Map Following Planned Trip of Single Mfp. Event Evaluation teams,established.W/970428 Ltr ML17292A8311997-04-28028 April 1997 LER 97-005-00:on 970327,valid Reactor Scram Signal Received Due to Low Water Level Condition During Preparations for SRV Testing.Caused by Risks & Consequences of Decisions Not Completely Identified.Restored Water level.W/970428 Ltr ML17292A8251997-04-21021 April 1997 LER 97-003-00:on 970320,notification of Noncompliance W/Ts as TS SRs for Response Time Testing Were Not Being Met for Specified Instrumentation in Rps,Pcis & Eccs.Requested Enforcement Discretion for One Time exemption.W/970421 Ltr ML17292A7431997-03-20020 March 1997 LER 97-002-00:on 970218,determined That Rod Block Monitor (RBM) Calibr Values Were Not Set IAW Tech Specs.Caused by Calibr Procedures Inadequacies.Revised & re-performed RBM Channel Calibr procedures.W/970330 Ltr ML17292A7401997-03-13013 March 1997 LER 97-001-00:on 970211,reactor Water Cleanup Sys Blowdown Flow Isolation Setpoint Was Slightly Above TS Allowable Valve Occurred Due to Calculation Error.Lds Fss LD-FS-15 LD-FS-16 Were Declared inoperable.W/970313 Ltr ML17292A6641997-01-22022 January 1997 LER 96-009-00:on 961220,miscalculation of Instantaneous Overcurrent Relay Settings Resulted in Inoperability of safety-related Equipment.Caused by Utilization of Inappropriate Design.Testing Was completed.W/970122 Ltr ML17292A6461997-01-0606 January 1997 LER 96-008-00:on 961205,failure to Comply with TS Action Requirement for Emergency Core Cooling Sys Actuation Instrumentation Occurred Due to Unidentified Inoperability Condition.Pmr initiated.W/970106 Ltr ML17292A6371996-12-19019 December 1996 LER 96-007-00:on 961122,electrical Breakers Were Not Seismically Qualified in Test/Disconnect Position.Circuit Breaker Mfg Did Not Consider Raced Out Breaker Position During Testing.Relocated Circuit breakers.W/961217 Ltr ML17292A4121996-08-0808 August 1996 LER 96-006-00:on 960709,average Power Range Monitor Rod Block Downscale Surveillance Not Performed Prior to Entry Into Mode 1.Caused by long-standing Misinterpretation of Requirements of Tss.Procedures revised.W/960808 Ltr ML17292A3801996-07-24024 July 1996 LER 96-004-00:on 960624,plant Was Manually Scrammed by Control Room Personnel Due to Reactor Water Level Transient Experienced During Testing of Digital Feedwater Sys.Caused by Programming Error.Sys Was corrected.W/960724 Ltr ML17292A3771996-07-24024 July 1996 LER 96-005-00:on 960624,determined Missed Surveillance Test Re Channel Check of Average Power Range Monitor.Caused by Inadequate Procedures.Revised Surveillance Procedure Re When APRM Checks Must Be performed.W/960724 Ltr ML17292A3641996-07-12012 July 1996 LER 96-003-00:on 960615,required Surveillance Test Not Performed When Required by TS 3.4.1.3.Caused by Inadequate Procedures.Implementing Surveillance Procedure & Reactor Plant Startup Procedures revised.W/960712 Ltr ML17292A3361996-06-20020 June 1996 LER 96-002-00:on 960504,critical Bus SM-8 Lost Power When Supply Breaker 3-8 Tripped.Caused by Personnel Error. Operators Counselled & Procedures revised.W/960620 Ltr ML17292A2861996-05-24024 May 1996 LER 96-001-00:on 960425,inadvertent ESF Actuations Occurred Due to Tripping of Temporary Power Supply to IN-3.Caused by Personnel Error.Operations Restored to IN-3 Loads & Reset ESF actuations.W/960524 Ltr ML17291B0891995-10-19019 October 1995 LER 95-011-00:on 950919,failed to Comply W/Ts SR for RCIC Sys Due to Analysis Deficiency That Resulted in Inadequate Surveillance Test Procedure.Surveillance Procedure Revised to Correct deficiency.W/951019 Ltr ML17291A9021995-07-0707 July 1995 LER 95-010-00:on 950609,HPCS DG Declared Inoperable Due to Discovery That TS Test Method Incomplete.Caused by Inadequate Testing Procedure.Test Procedure for HPCS DG Reviewed & Special Test Procedures written.W/950707 Ltr ML17291A9031995-07-0707 July 1995 LER 95-009-00:on 950607,inadvertent MSIV Closure Occurred During Surveillance Test Due to Poor Communication Between Test Team.Determined That MSIV Closure Not Valid Because Closure Not Triggered by Plant conditions.W/950707 Ltr ML17291A8501995-06-0808 June 1995 LER 95-006-01:on 950405,reactor Scram Occurred During Surveillance Testing Due to Protective Sys Relay Failure. Replaced Failed Relay Before Plant Startup ML17291A8101995-05-12012 May 1995 LER 95-008-00:on 940125,TS Wording Lead to Potential TS Violation.Caused by Lack of Clarity in Ts.Submitted Improved TS for Plant to Provide Addl clarity.W/950512 Ltr ML17291A7841995-05-0505 May 1995 LER 95-007-00:on 950222,emergency Diesel Start Occurred Due to Voltage Transient on BPA Grid.Confirmation Was Received at 17:51 H That Disturbance Had Originated in BPA Grid ML17291A7801995-05-0404 May 1995 LER 95-006-00:on 950405,main Turbine Trip Occurred During Performance of Surveillance Test Due to Protective Sys Relay Failed.Replaced Failed Relay Before Plant startup.W/950504 Ltr ML17291A7851995-05-0303 May 1995 LER 95-005-00:on 950222,inoperable IRM Had Been Relied Upon to Meet TS Requirements During Reactor Startup.Caused by Lack of Neutron Source to Test Instrumentation. Sys Knowledge Gained Will Be incorporated.W/950503 Ltr ML17291A7071995-03-25025 March 1995 LER 95-004-00:on 950226,malfunction in Main Turbine DEH Control Sys Caused All Four High Pressure Turbine Governor Valves to Rapidly Close.Caused by Blown Fuse.Suspected Faulty Circuit Card replaced.W/950325 Ltr ML17291A7011995-03-20020 March 1995 LER 95-002-00:on 950218,automatic Reactor Scram Occurred. Caused by Erroneous Positioning of Control During Performance of Scheduled Periodic Functional Test.Control repositioned.W/950320 Ltr 1999-07-20
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML17284A9001999-10-31031 October 1999 Rev 0 to COLR 99-15, WNP-2 Cycle 15,COLR GO2-99-177, LER 99-S01-00:on 990903,failure to Take Compensatory Measure within Required Time Upon Failure of Isolation Zone Microwave Unit,Was Noted.Caused by Personnel Error.Provided Refresher Training on Compensatory Measures.With1999-10-0101 October 1999 LER 99-S01-00:on 990903,failure to Take Compensatory Measure within Required Time Upon Failure of Isolation Zone Microwave Unit,Was Noted.Caused by Personnel Error.Provided Refresher Training on Compensatory Measures.With ML17284A8941999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for WNP-2.With 991012 Ltr ML17284A8801999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for WNP-2.With 990910 Ltr ML17284A8691999-07-31031 July 1999 Monthly Operating Rept for July 1999 for WNP-2.With 990813 Ltr ML17292B7421999-07-20020 July 1999 LER 99-001-00:on 990628,ESF Signal Closed All Eight MSIVs While Plant Was Shutdown.Caused by Failure of Relay RPS-RLY-K10D.Subject Relay Was Replaced & Tested on 990630. with 990720 Ltr ML17292B7271999-06-30030 June 1999 Monthly Operating Rept for June 1999 for WNP-2.With 990707 Ltr ML17292B6961999-05-31031 May 1999 Monthly Operating Repts for May 1999 for WNP-2.With 990608 Ltr ML17292B6641999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for WNP-2.With 990507 Ltr ML17292B6391999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for WNP-2.With 990413 Ltr ML17292B5871999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for WNP-2.With 990311 Ltr ML17292B5571999-01-31031 January 1999 Monthly Operating Rept for Jan 1999 for WNP-2.With 990210 Ltr ML17292B5621999-01-31031 January 1999 Rev 1 to COLR 98-14, WNP-2 Cycle 14 Colr. ML17292B5341999-01-15015 January 1999 Part 21 Rept Re Incorrect Modeling of BWR Lower Plenum Vol in Bison.Defect Applies Only to Reload Fuel Assemblies Currently in Operation at WNP-2.BISON Code Model for WNP-2 Has Been Revised to Correct Error ML17292B5331999-01-15015 January 1999 Part 21 Rept Re XL-S96 CPR Correlation for SVEA-96 Fuel. Defect Applies Only to WNP-2,during Cycles 12,13 & 14 Operation.Evaluations of Defect Performed by ABB-CE ML17292B4791998-12-31031 December 1998 Washington Public Power Supply Sys 1998 Annual Rept. with 981215 Ltr ML17292B5351998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for WNP-2.With 990112 Ltr ML17292B5741998-12-31031 December 1998 WNP-2 1998 Annual Operating Rept. with 990225 Ltr ML17284A8231998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for WNP-2.With 981207 Ltr ML17284A8081998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for WNP-2.With 981110 Ltr ML17292B4451998-10-27027 October 1998 LER 98-012-01:on 980715,failure to Comply with Requirements of TS SR 3.8.4.7 Was Noted.Caused by Inadequate Work Practices.Training Session Was Held with Personnel.With 981027 Ltr ML17284A7831998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for WNP-2.With 981007 Ltr ML17284A7491998-09-10010 September 1998 WNP-2 Inservice Insp Summary Rept for Refueling Outage RF13 Spring,1998. ML17284A7561998-09-0303 September 1998 LER 98-013-00:on 980805,ESF Actuations Were Noted Due to Deenergization of Vital Electrical Bus SM-8.Caused by Inadequate Direction in Troubleshooting Plan.Will Conduct Training for Engineering Personnel.With 980903 Ltr ML17284A7571998-09-0202 September 1998 LER 98-014-00:on 980807,completion of TS 3.8.1.F Required Shutdown Due to Inoperability of EDG-2 Was Noted.Caused by Degraded Voltage Regulator for DG-2.Replaced Voltage Regulator & Associated Scrs.With 980902 Ltr ML17284A7551998-09-0202 September 1998 LER 98-015-00:on 980808,discovered Reactor Coolant Pressure Boundary Leak During Shutdown Conditions.Caused by Leakage from Socket Weld (Fwb 63) on Elbow Connection.Failed Piping Connection Was Replaced.With 980902 Ltr ML17284A7681998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for WNP-2.With 980915 Ltr ML17284A7311998-08-17017 August 1998 LER 98-012-00:on 980716,determined That 24-month SR 3.8.4.7 Had Not Been Fulfilled within Specified Frequency.Caused by Inadequate Work Practices.License Requested & Received Enforcement Discretion Re Battery Svc test.W/980817 Ltr ML17284A7261998-07-31031 July 1998 Monthly Operating Rept for July 1998 for WNP-2.W/980810 Ltr ML17284A7121998-07-23023 July 1998 LER 98-006-01:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of 10CFR50,App R Calculations for High Impedance Faults.Caused by Inadequate Work Practices.Implemented Procedural Changes ML17284A6951998-07-17017 July 1998 LER 98-011-00:on 980617,ECCS Pump Room Flooding Was Noted Due to FP Sys Pipe Break.Caused by Inadequate Design of FP Sys.Detailed Review of FP Sys Design Was Conducted. W/980717 Ltr ML17284A6961998-07-15015 July 1998 LER 98-010-00:on 980615,TS Required Shutdown Due to Inoperability of TIP Sys Isolation Valve Was Noted.Caused by Improper Installation of TIP Tubing.Reattached Affected Tubing & Inspected Other TIP tubing.W/980715 Ltr ML17284A6731998-07-0101 July 1998 LER 98-009-00:on 980606,nuclear Steam Supply Shutoff Sys Group 3 & 4 Isolations During Testing Was Noted.Caused by Procedural Deficiency.Counseled Individuals Involved in preparation.W/980701 Ltr ML17284A6751998-06-30030 June 1998 Ro:On 980617,flooding of RB Northeast Stairwell with Consequential Flooding of Two ECCS Pump Rooms.Caused by Inadequate Fire Protection Sys Design.Pumped Out Water from Affected Areas to Point Below Berm Areas of Pump Rooms ML17284A6641998-06-24024 June 1998 LER 98-008-00:on 980531,inadvertent Full Scram During RPV Leak Testing in Mode 4 Was Noted.Caused by Change in Mgt Techniques.Revised Procedures to Take Into Account Addl Water Head in Pressure Sensing lines.W/980624 Ltr ML17284A6651998-06-24024 June 1998 LER 98-007-00:on 980530,inadvertent Full Scram & Division 1 ECCS Injection Was Noted.Caused by Failure to Meet Mgt Work Practice Expectation When Encountering Deficient Procedure. Incident Review Board Convened to Review event.W/980624 Ltr ML17284A6631998-06-19019 June 1998 LER 98-006-00:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of App R Calculations for High Impedance Fault Analysis.Caused Indeterminate. Implemented Procedural Changes Involving Operator Action ML17284A6551998-06-0404 June 1998 LER 98-005-00:on 980506,potential for Failure of RHR Sys Valve to Close on Isolation Signal Was Noted.Caused by Design Deficiency.Caution Tag Was Placed on RHR-V-40 Control Switch to Inform Plant Operators of limitation.W/980604 Ltr ML17284A6421998-06-0101 June 1998 LER 98-004-00:on 980502,determined That Primary Containment Penetration Overcurrent Protection Does Not Meet Reg Guide 1.63 Requirements.Caused by Inadequate Design Changes. Installed Addl Fuse in RHR-MO-9 circuit.W/980601 Ltr ML17284A6491998-05-31031 May 1998 Rev 0 to COLR 98-14, WNP-2,Cycle 14 Colr. ML17292B4031998-05-31031 May 1998 Monthly Operating Rept for May 1998 for WNP-2.W/980608 Ltr ML17292B3921998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for WNP-2.W/980513 Ltr ML17292B3291998-04-0909 April 1998 LER 98-003-00:on 980311,WNP-2 Experienced SCRAM Signal as Result of Low Rpv.Caused by Less than post-SCRAM Operational Strategy for Resetting SCRAM Signal in Conditions.Changes in post-SCRAM Operational Strategy implemented.W/980409 Ltr ML17292B3281998-04-0909 April 1998 LER 98-002-00:on 980311,reactor Scram & Plant Transient Occurred,Due to Failed Closed Main Steam Isolation Valve. Caused by Loss of Pneumatic Actuating Supply Pressure. Problem Evaluation Request Written for Failure of MS-V-22D ML17292B3371998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for WNP-2.W/980409 Ltr ML17292B2641998-03-0404 March 1998 Performance Self Assessment,WNP-2. ML17292B2661998-03-0404 March 1998 LER 98-001-00:on 980203,automatic Start of HPCS EDG Was Noted.Caused by Operator Error.Operations Crew Stabilized Plant at Approximately 75% Reactor Power & Investigation of Event Was initiated.W/980304 Ltr ML17292B2911998-02-28028 February 1998 Monthly Operating Rept for Feb 1998 for WNP-2.W/980313 Ltr ML17284A7971998-02-17017 February 1998 Rev 28 to Operational QA Program Description, WPPSS-QA-004.With Proposed Rev 29 ML17292B3591998-02-12012 February 1998 WNP-2 Cycle 14 Reload Design Rept. 1999-09-30
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Text
CATEGORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSIOH NBR:9606260184 DOC.DATE: 96/06/20 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION PFITZER,B. Washington Public Power Supply System BEMIS,P.R. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION
SUBJECT:
LER 96-002-00:on 960504,critical bus SM-8 lost power when Supply breaker 3-8 tripped. Caused by personnel error.
Operators counselled s procedures revised.W/960620 ltr.
DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR I ENCL ( SIEE:
TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.
5 T E
NOTES:
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD4-2 PD 1 1 COLBURN,T 1 1 R
INTERNAL: ACRS 1 1 AEOD D AB 2 2
~~
AEOD/SPD/RRAB 1 1 E C TER 1 1 NRR/DE/ECGB 1 1 R~~B 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 RES/DSIR/EIB 1 1 RGN4 FILE 01 1 1 D
EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 2 2 NOAC MURPHY,G.A 1 1 NOAC POOREEW. 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 M
N NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5D-5(EXT. 415-2083) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED'.
FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 26 ENCL 26
WASH I.'iGTO.'v PUBLIC POWER SUPPLY SYSTEM PO. Box 968 ~ 3000 George 11rrshirrgton 11'ar ~ Richland, 11raslrington 99352-0968 ~ (509) 372-5000 June 20, 1996 G02-96-124 Docket No. 50-397 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:
Subject:
NUCLEAR PLANT WNP-2, OPERATING LICENSE NPF-21, VOLUNTARYLICENSEE EVENT REPORT NO. 96-002-00 Transmitted herewith is voluntary Licensee Event Report No. 96-002-00 for WNP-2. This event is not reportable under 10CFR50.72 or 10CFR50.73. This report is submitted voluntarily for information.
Should you have any questions or desire additional information regarding this matter, please call me or Ms. Lourdes Fernandez at (509) 377-4147.
Res tfully, P. R Bemis (Mail Drop PE20)
Vice President, Nuclear Operations Enclosure cc: LJ Callan, NRC RIV NRC Sr. Resident Inspector, MD927N (2)
TG Colburn, NRR INPO Records Center - Atlanta, GA KE Perkins, Jr., NRC RIV, WCFO DL Williams, BPA, MD399 NS Reynolds, Winston & Strawn 9606260i84 960620 PDR ADOCK 05000397 8 PDR
0 LICENSEE EVENT REPORT (LER)
TACAI TV NAME (I I DocxET MA(TER (I(
Washington Nuclear Plant Unit 2 0 5 0 0 0 3 9 7 1 ( 4 TITLE(e( INADVERTENT LOSS OF POWER TO CRITICAL BUS AND EDG START DUE TO CLEARANCE ORDER RESTORATION ACTIVITY (ER NVMSER (el 0 IIRR TACAITKS e(VOLV(D ee DOCKET (ARISTA(et N/A 0 5 0 0 05 04 96 96 0 0 2 0 0 06 20 96 0 5 0 0 OtERATSIC Uee R(PORT IS SUOMI(TEO tVRSVANT TO THE REOUIR(MENTS Oc 'lo CIR: II II MODE (SI
- ( 20.402(b) ( 20.405c ( 50.73(e)(2)(iv) I I 73.71(b)
( 20.405(s)(l)(i) ( ( 50.36(c)(l) ) 50.73(s)(2)(v) ) 73.71(c) tOWER LEV(L 20.405(s) (1) (ii) 50.36(c)(2) 50.73(e)(2)(vrl) X OTHER (Specify (n Abstrect be(ow end
) ( ( (
(I(e in Text, NRC Form 366A)
Q 0 Q ( 20.405(e)(l)(iii) ) ( 50.73(s)(2)(i) ) 50.73(e)(2)(vii)A I 20.405(s)(l)(iv) ) ( 50.73(s)(2)(ii) 50.73(s)(2)(viii) B 20.405(s)(1)(v) I I 50.73(s)(2)(NI) ) 50.73(SH2)(x)
Uc(NTEE CONTACT SOR Ties LER I It(
I(((tIIONE NUMI(R Bill Pfitzer, Licensing Engineer 509 377-2419 COMt(ETE OtC LSC IOR EACH COMt(HANT TALVRE DESCRR(D IN TITS R(toRT ((el MAIREAD. R(toRTAS(E MAIREAD. R(PORTA(LE TURLR TO MVDS TVR(R TO MV(DS SVttLEMENTAL REtoel EXTEC(m ((4( EXPECTED SUBMISSION YES (i) yes, complete EXPECTED SUBM(SSION DATE) (X( ko DATE (15)
ABSTRACI')6)
On May 4, 1996 at 0142, with the reactor defueled, critical bus SM-8 lost power when supply breaker 3-8 tripped. As a result, emergency diesel generator (EDG) 2 auto started and the backup transformer automatically provided power to SM-8. Detailed investigation into this event determined the cause to be accidental opening of the non-critical bus SM-3 potential transformer (PT) fuse compartment by an equipment operator (EO) performing restoration activities for a clearance order.
Event notification was made to the NRC pursuant to the requirements of 10 CFR 50.72(b)(2) as an Engineered Safety Feature (ESF) actuation. This notification was subsequently retracted after a detailed review of the event and the actuated equipment. The WNP-2 FSAR does not specify the EDGs as an Engineered Safety Feature. This LER is submitted on a voluntary basis.
LICENS EVENT REPORT (LER) TEXT CO INUATlON stovcM lal stvMMst Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 96 002 0 0 2 " 4 TEXT (17)
Even De cri i n On May 4, 1996 at 0142, with the reactor defueled, the control room received alarms indicating an undervoltage condition on non-critical bus [BU] SM-3. Breaker [BKR] 3-8 tripped due to the undervoltage condition causing a loss of power to critical bus SM-8. As a result, EDG-2 [DG]
auto started, the backup transformer [XFMR] automatically provided power to the SM-8 bus, and residual heat removal pump 2B (RHR-P-2B) [BO,P], which was operating in the fuel pool cooling
[DA] assist mode, experienced a temporary loss of power. Plant restoration activities were completed at approximately 0306.
Immediate orrective Action Immediately after the incident, Operations management suspended ongoing clearance order restoration activities and secured the area around the SM-3 auxiliary electrical cubicle to support investigation activities.
A Problem Evaluation Request (PER) was initiated.
RHR-P-2B was returned to service in the fuel pool cooling assist mode after approximately 45 minutes.
Plant electrical lineup and equipment restoration was completed at approximately 0306.
Further Evalua ion During the Incident Review Board (IRB) investigation, the EO reported that he had opened and closed the door of the SM-3 auxiliary electrical cubicle in preparation for restoration of a clearance order associated with transformer TR-S. The EO stated that after looking inside the cubicle he shut the door and then heard relays chatter. He speculated he had jarred the relays while closing the cabinet door. Event evaluation, including further interviews of the EO involved, determined the following:
~ Momentary opening of the SM-3 bus PT fuse compartment, which is a~d'scent to the compartment specified by the clearance, would have caused all the auto actions which occurred during this event. Both fuse compartments are located inside the SM-3 auxiliary electrical cubicle which must be opened to view the compartments. The compartment doors utilize a protective feature which disconnects the fuses as the compartment door is opened.
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Sf QUCMNl RKVISKIH NUMSOI HUMOR Washington Nuclear Plant - Unit 2 05 0 0 0 3 9 7 96 002 0 0 3 oF 4 TEXT (l7)
The door latch for the SM-3 bus PT fuse compartment was found in the 11:30 (just closed) position rather than the 9:00 (fully closed) position as expected.
PT fuse disconnects of this type can be easily opened and re-closed in approximately 1-2 seconds.
~ The control room alarm printer "SM-3 UNDERVOLTAGE" indication took about 2 seconds to return to normal.
~ In an effort to reproduce an inadvertent relay operation, the SM-3 auxiliary electrical cubicle door was repeatedly slammed. No operation of SM-3 undervoltage relays due to mechanical jarring or bumping was observed.
~ The maximum length of time for an HFA undervoltage relay to trip and return to normal due to mechanical jarring or bumping is approximately 40 to 50 milliseconds. In this case, the relay which must actuate after the undervoltage relay to effect opening of breaker 3-8 requires the undervoltage signal to be approximately 1.0 second in duration.
The physical evidence listed above led the IRB to postulate three possible causes for the SM-3 undervoltagb condition. These potential causes were:
~ Slamming the SM-3 auxiliary electrical cubicle door which jarred the undervoltage relays of SM-3 causing breaker 3-8 to trip.
~ Dirty contacts on the SM-3 bus PT fuse stabs which caused poor contact, an undervoltage condition and tripping of breaker 3-8.
~ Opening of the SM-3 bus PT fuse compartment which caused an undervoltage condition and tripping of breaker 3-8.
After careful consideration, Operations management concluded the cause of the event was momentary opening of the SM-3 bus PT fuse compartment by the EO. It was further concluded that the EO operated the SM-3 bus PT fuse compartment and, upon realizing his error, hastily reclosed the PT compartment leaving the compartment in the abnormal condition found by the IRB investigators. This conclusion is further supported by the information recorded on the control room alarm printer and the information obtained during testing of the components involved.
This LER is submitted on a voluntary basis.
0 LICENS EVENT REPORT (LER) TEXT CO INUATION SfOUCMtNL ROI5ON
~MA NVM80l Washington Nuclear Plant - Unit 2 05 0 0 0 3 9 7 96 002 0 0 4 o" 4 TEXT u7)
Root au e The root cause for this event is personnel error. The SM-3 bus PT fuse compartment was inadvertently opened, causing an SM-3 undervoltage signal.
A contributing cause was inadequate pre-job brief. The Production Reactor Operator (RO) and Senior Reactor Operator (SRO) did not address the potential adverse consequences of operation of the bus PT fuse compartment.
An additional contributing cause was failure to follow the procedure requirements to identify clearance order steps for PT fuse restoration as requiring simultaneous verification.
Further orrective Action Personnel action appropriate to the circumstances was taken with the EO.
The Production RO and SRO were counseled concerning the necessity of performing adequate pre-job briefs prior to performance of critical clearance activities.
The procedures/instructions governing clearance order preparation will be revised to ensure the need for simultaneous verification is noted on the required clearance order steps.
Assessment f fe Conse uence The safety consequences of this event are minimal. The reactor was defueled at the time this event occurred. Expected automatic actions occurred including auto starting of EDG-2 and re-energization of SM-8 from the backup transformer. RHR-P-2B, which was operating in the fuel pool cooling assist mode, tripped as a result of the loss of power but was restored after approximately 45 minutes. Estimated time to boil at the time of this event was 52 hours6.018519e-4 days <br />0.0144 hours <br />8.597884e-5 weeks <br />1.9786e-5 months <br />.
Previous Similar Events Previous LERs documenting personnel error resulting in actuation of safety-related equipment are as follows:
LER 96-001 involved inadvertent ESF actuations due to tripping of a temporary power supply to IN-3 by outage electricians.
LER 95-002 involved Operations personnel operating the wrong lever during a main turbine test resulting in turbine trip and reactor scram.