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| {{#Wiki_filter:ACCEI.ERATED'OCUMENT DISTKKUTION SYSTEM REGULA'ZOY INFORMATION DISTRIBUTIO!SYSTEM (RIDE)ACCESSION NBR:9306300206 DOC.DATE: 93/06/23 NOTARIZED: | | {{#Wiki_filter:ACCEI.ERATED'OCUMENT DISTKKUTIONSYSTEM REGULA'ZOY INFORMATION DISTRIBUTIO!SYSTEM (RIDE) |
| NO DOCKET FACIL 50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH.NAME'UTHOR AFFILIATION KNUETTEL,E.T. | | ACCESSION NBR:9306300206 DOC.DATE: 93/06/23 NOTARIZED: NO DOCKET FACIL 50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH. NAME KNUETTEL,E.T. |
| Tennessee Valley Authority ZERINGUE,O.J. | | 'UTHOR AFFILIATION Tennessee Valley Authority ZERINGUE,O.J. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION'UBJECT: |
| Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION'UBJECT: | | LER 93-007-00:on 930527,mechanical seal for 2A reactor recirculation pump failed. Caused by inadequate procedures. |
| LER 93-007-00:on 930527,mechanical seal for 2A reactor recirculation pump failed.Caused by inadequate procedures. | | Site procedures revised to require seal purge flow to be established.W/930623 ltr. |
| Site procedures revised to require seal purge flow to be established.W/930623 ltr.DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE: TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.NOTES: RECIPIENT ID CODE/NAME PD2-4 ROSS,T.INTERNAL: ACNW AEOD/DOA AEOD/ROAB/DSP NRR/DE/EMEB NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRSS/PRPB NRR/DSSA/SRXB RES/DSIR/EIB EXTERNAL'G&G BRYCEF J~H NRC PDR NSIC POOREFW COPIES LTTR ENCL 1 1 1 1 2 2 1 1 2 2 1 1 1 1.1 1 2.2 1 1 1 1 2 2 1 1 1 1 RECIPIENT ID-CODE/NAME PD2-4-PD ACRS AEOD/DSP/TPAB NRR/DE/EELB NRR/DORS/OEAB NRR/DRCH/HICB NRR/DRIL/RPEB RR'/DSSA/SPLB EG FILE 02 RGN2 FILE 01 L ST LOBBY WARD NSIC MURPHYFG.A NUDOCS FULL TXT COPIES LTTR ENCL 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 NOTE TO ALL"RIDS" RECIPIENTS: | | DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE: |
| PLEASE HELP US TO REDUCE WASTEI CONTACI'HE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT.504-2065)TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR'32 ENCL 32 | | TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc. |
| | NOTES: |
| | RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID- CODE/NAME LTTR ENCL PD2-4 1 1 PD2-4-PD 1 1 ROSS,T. 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DORS/OEAB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB .1 1 NRR/DRIL/RPEB 1 1 NRR/DRSS/PRPB 2 . |
| | 2 RR'/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 EG FILE 02 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL'G&G BRYCEF J ~ H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHYFG.A 1 1 NSIC POOREFW 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL"RIDS" RECIPIENTS: |
| | PLEASE HELP US TO REDUCE WASTEI CONTACI'HE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED! |
| | FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR '32 ENCL 32 |
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| Tennessee Valley Autftority, Post Office Box 2000, Decatur, Alabama 35609.2000 O.J."Ike" Zeringue Vice President. | | Tennessee Valley Autftority, Post Office Box 2000, Decatur, Alabama 35609.2000 O. J. "Ike" Zeringue Vice President. Browns Ferry Nuclear Plant June 23, 1993 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 |
| Browns Ferry Nuclear Plant June 23, 1993 U.S.Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C.20555 | |
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| ==Dear Sir:== | | ==Dear Sir:== |
| TVA-BROWNS FERRY NUCLEAR PLANT (BFN)UNITS 1, 2, AND 3-DOCKET NOS.50-259, 260, AND 296-FACILITY OPERATING LICENSE DPR-33, 52, AND'8-LICENSEE EVENT REPORT 50-260/93007 The enclosed report provides details concerning a manual reactor shutdown due to a recirculation pump seal leak.This event occurred during startup from the Unit 2, Cycle 6 refueling outage.This report is submitted in accordance with 10 CFR 50.'73(a)(2)(i)(A) due to the manual shutdown of the plant as required by technical specification. | | |
| | TVA BROWNS FERRY NUCLEAR PLANT (BFN) UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 260, AND 296 FACILITY OPERATING LICENSE DPR-33, 52, AND'8 LICENSEE EVENT REPORT 50-260/93007 The enclosed report provides details concerning a manual reactor shutdown due to a recirculation pump seal leak. This event occurred during startup from the Unit 2, Cycle 6 refueling outage. |
| | This report is submitted in accordance with 10 CFR 50.'73(a)(2)(i)(A) due to the manual shutdown of the plant as required by technical specification. |
| requirements. | | requirements. |
| Sincerely, 0.J.Zeringue Enclosure cc: See page 2 rgu>9306300206 930623 PDR ADOCK 05000260-PDR 0 | | Sincerely, |
| U.S.Nuclear Regulatory Commission June 23, 1993 cc (Enclosure): | | : 0. J. Zeringue Enclosure cc: See page 2 rgu> |
| INFO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 Paul Krippner American Nuclear Insurers Town Center, Suite.300S 29 South Main Street West Hartford, Connecticut 06107 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, P.O.Box 637 Athens, Alabama 35609-2000 Regional Administrator U.S.Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 2900 Atlanta, Georgia 30323 Thierry, M.Ross U.S.Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 | | 9306300206 930623 PDR ADOCK 05000260 |
| | -PDR |
| | |
| | 0 U.S. Nuclear Regulatory Commission June 23, 1993 cc (Enclosure): |
| | INFO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 Paul Krippner American Nuclear Insurers Town Center, Suite .300S 29 South Main Street West Hartford, Connecticut 06107 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, P.O. Box 637 Athens, Alabama 35609-2000 Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 2900 Atlanta, Georgia 30323 Thierry, M. Ross U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 |
| | |
| | NRC Form 366 NUCLEAR REGULATORY COttlISSION Approved OHB No. 3150-0104 (6-09) Expires 4/30/92 LICENSEE EVENT REPORT (LER) |
| | FACILITY NAHE (1) IDOCKET NUMBER ( |
| | r wn rr N 1 r P TITLE (4) Reactor Shutdown Due To Recirculation Pump Seal Leakage. |
| | V T D SEQUENTIAL I IREVISIONI I I I FACILITY NAHES IDOCKET NUHBER(S) |
| | I I I I I N 0 I I I I I I I I I I I OPERATING I ITHIS REPORT IS SUBHITTED PURSUANT TO THE REQUIREHENTS OF 10 CFR 5: |
| | NODE w I I N I20.402(b) IZ0.405(c) I50.73(a)(2)(iv) I73.71(b) |
| | POWER I I20.405(a)( l)(i ) I ISO 36(c)(1) I50.73(a)(2)(v) I73.71(c) |
| | LEVEL I20.405(a)( l)(ii) I50.36(c)(2) I50.73(a)(2)(vii) IOTHER (Specify in I |
| | I20.405(a)( l)(iii ) I~I50.73(a)(2)(i) I50.73(a)(2)(viii)(A) I Abstract below and'n I20.405(a)( l)(iv) I50.73(a)(2)(ii) I50.73(a)(2)(viii)(B) I Text, NRC Form 366A) |
| | .4 1 v 1 I AREA CODE T. n |
| | ' |
| | m li n i n i r N F P NT IREPORTABLEI IREPORTABLEI I I Y T N N F I I I I 0 P I I PP N P I SUBHISSION I I I f m 1 D ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines) (16) |
| | On May 27, 1993, at 2015 hours, while operating at approximately eight percent power in the run mode following the BFN Unit 2 refueling outage, the Number 2 mechanical seal for the 2A Reactor Recirculation pump failed and the pump was removed from service. The Limiting Condition for Operation for Technical Specification 3.6.F.1 (TS) was entered which requires the plant be placed in a hot shutdown condition within 24 hours after taking one recirculation loop out of service. At 2225, an orderly plant shutdown was initiated in accordance with TS requirements. On May 28, at 0140, plant shutdown was completed in an orderly manner. This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(A) as a condition that resulted in manual shutdown of the plant required by the plant's TS. |
| | The root cause of the recirculation pump seal failure was due to inadequate procedures. An investigation of this event determined that the pump seal failed due to a small amount of loose particles (e.g., welding related material) collecting in the seal spring packing assembly causing the spring to jam and the seal not to seat properly. To prevent this problem from recurring, TVA revised site procedures before to require seal purge flow to be established, to supply water to the seal cavity opening the recirculation pump isolation valves following maintenance activities. |
| | NRC Form 366(6-89) |
| | |
| | ~I NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION Approved OHB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER) |
| | TEXT CONTINUATION FACIL'ITY NAME (1) IDOCKET NUMBER (2) |
| | I I I I SEQUENTIAL I I REVI S ION I I I I I Browns Ferry Uni t 2 I 8 I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17) |
| | I. PLANT CONDITIONS Unit 2 was in the run mode at approximately eight percent power following the Cycle 6 refueling outage. Units 1 and 3 were shutdown and in a defueled condition. |
| | II- DESCRIPTION OF EVENT A. ~~at: |
| | On May 27', 1993, Operations personnel in the control room received indication of an abnormal seal pressure on the 2A recirculation [AD] |
| | pump's number 2 seal. An inspection team entered the drywell at 1945 to check the recirculation pump seal alarm and to check for leakage. While the inspection team was in the drywell, the number 2 seal on the 2A recirculation pump started leaking excessively (approximately 5 gpm). |
| | Control room personnel were notified at 2013 of the leaking seal. At 2015 the 2A Reactor Recirculation System pump was removed from service and Technical Specification (TS) Limiting Condition for Operation (LCO) 3.6.F.l was entered. This TS section requires the plant be placed in a hot shutdown condition within 24 hours after taking one recirculation loop out of service. |
| | At 2225, an orderly plant shutdown was initiated in accordance with TS 3.6.F.l. Since replacement of the recirculation pump seal could not be performed within the TS LCO, Unit 2 was shutdown and an Unusual Event (UE) was declared. On May 28, at 0140, the UE was terminated after all control rods were inserted and the mode switch was placed in the shutdown position. |
| | Subsequent investigation by TVA and representatives from the recirculation pump manufacturer determined that the cause of the seal leak was due to small particles in the recirculation system inhibiting the pump seal spring assembly. |
| | This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(A) due to the completion of plant shutdown required by TS requirements. |
| | NRC Form 366(6-'89) |
| | |
| | I J |
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| | NRC Form 366A U. . NUCLEAR REGULATORY COHHISSION Approved OHB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER) |
| | TEXT CONTINUATION FACILITY NAHE (1) IOOCKET. NUHBER (2) |
| | I ISE()UENTIAL I IREYISIONI I I I I Browns Ferry Uni t 2 I I I I I F |
| | TEXT (If more space is required, use additiona1 NRC Form 366A's) (17) |
| | B. Ia t t t t t t t h None. |
| | C. |
| | May 27, 1993, at 2015 CDT 2A Reactor Recirculation System pump removed from service due to seal leakage and entered 24-hour LCO. |
| | May 27, 1993, at 2225 CDT Initiated shutdown of Unit 2 reactor to cold shutdown, declared UE, and notified NRC within one hour of event in-accordance with 10 CFR 50.72(a)(3) and 50.72(b)(l)(i)(A). |
| | May 28, 1993, at 0140 CDT UE terminated after all control rods were inserted and mode switch placed in shutdown'osition. |
| | D. th None. |
| | E 'h V e Abnormal Reactor Recirculation System. pump seal pressure indication in the control room alerted Operations personnel. |
| | Operations personnel responded to the abnormal Reactor Recirculation System pump seal pressure indication by sending an inspection team into the drywell to check the pump seal alarm and for any seal leakage. Unit 2 was shutdown in an orderly fashion, due to the 2A Reactor Recirculation System pump's number 2 seal leaking excessively, as required by the plant's TS. |
| | G. |
| | None. |
| | NRC Form 366(6-89) |
| | |
| | 0 C |
| | |
| | NRC Form'366A U.. NUCLEAR REGULATORY COMMISSION Approved OMB No. 3150-0104 (6-89) Expires 4/30/92 |
| | 'LICENSEE EVENT REPORT (LER) |
| | TEXT CONTINUATION FACILITY NAME (1) (OOCKET,NUMBER (2) PA I i SE()VENT IAL i i REVISION ( |
| | Browns Ferry Uni t 2 I I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17) |
| | III. CAUSE OF THE EVENT The immediate cause of the event was excessive leakage past the 2A Reactor Recirculation System pump mechanical seal. |
| | B. @~tstgI~: |
| | The root cause of the event was inadequate procedures. Specifically, plant procedures failed to require seal purge flow to be established, prior to restarting the recirculation pumps, to supply water to the seal cavity prior to opening the recirculation pump isolation valves following maintenance activities. Opening the recirculation pump valves prior to establishing seal purge flow allowed small particles to enter the seal spring assembly, which resulted in the pump seal leakage. |
| | An investigation performed by TVA and vendor personnel subsequent to the event determined that the pump seal failed due to a small amount of loose particles collecting in the seal spring packing assembly causing the spring to jam. The function of the seal spring packing assembly is to hold, the rotating face and carbon stationary face of the seal together. |
| | Very small amounts of debris in the spring assembly will cause the assembly to-malfunction. Jamming of the spring assembly caused the seal not to seat properly, which resulted in the excessive leakage. |
| | The loose particles collected from the seal assembly were sent to Southwest .Research Laboratory for material characterization. The laboratory results indicated that the average size of the particles was |
| | .008 square inches. The particle sizes ranged from .02 to .0016 square inches. The particles were determined to be weld related materials (i.e., |
| | iron particles and slag). |
| | C. |
| | The reactor vessel piping decontamination activities disturbed existing particles in the Reactor Recirculation System during the Unit 2, Cycle 6 refueling outage. The age and the origin of these particles are not known. |
| | NRC Form 366(6-89) |
| | |
| | ~i NRC Form 366A U.. NUCLEAR REGULATORY COHHISSION Approved OHB No. 3150-0104 (6-09) Expires 4/30/92 LICENSEE EVENT REPORT (LER) |
| | TEXT CONTINUATION FACILITY NAME -(1) IDOCKET NUHBER (2) |
| | I I I I SEqUENTIAL I I REVISIONI I I I I Browns Ferry Unit 2 I A I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17) |
| | C IV. ANALYSIS OF THE EVENT This event occurred with Unit 2 in the run mode at approximately eight percent power following the BFN Unit 2 refueling outage. Units 1 and 3 were shutdown and in a defueled condition. |
| | Drywell leakage increased and the seal pressure equalized across the two stages, alerting the operators of a recirculation pump seal malfunction. The pump leakage was calculated to be approximately 5.66 gpm during the shutdown process.'he seal construction is such that even during catastrophic seal failure, the maximum leakage is limited to approximately 60 gpm by the breakdown bushing with minimal impact on the containment pressure. At no time during the event was any safety system challenged. No safety consequences resulted from the event, since the affected systems responded properly to perform their intended safety functions. Therefore, the plant and the public safety was not adversely affected and the safety of the plant personnel was not compromised. The mode switch was placed in "Shutdown" on May 28, 1993, at 0140 hours and the condition of cold shutdown was achieved. |
| | V. CORRECTIVE ACTIONS tv t |
| | 'TVA personnel and representatives from the recirculation pump manufacturer disassembled the pump seal and inspected the mechanical seal assembly to determine cause of the leakage. |
| | B. tv At t TVA revised Operation Instruction 2-0I-68, "Reactor Recirculation System" to require seal purge flow to be established, prior to restarting the recircul'ation pump, to supply water to the seal cavity before opening the recirculation pump isolation valves following maintenance activities. |
| | Specifically, this revision requires that CRD purge flow be turned on before the suction or discharge valves are opened after any maintenance that requires draining the pump cavity. Maintenance Instruction MCI-068-PMP001, "Maintenance of Reactor Recirculation Pumps," was revised to require seal flow to be on following seal maintenance activities before the suction or discharge valves are opened. These procedure requirements will prevent the loose particles from collecting in the pump seal spring assembly. |
| | NRC Form 366(6-89) |
| | |
| | 0 NRC Form 366A U.. NUCLEAR REGULATORY COHHISSION Approved OHB No. 3150-0104 (6-09) Expires 4/30/92 LICENSEE EVENT REPORT (LER) |
| | TEXT CONTINUATION FACILITY NAHE (1) iDOCKET NUHBER (2) |
| | I I, I I SEQUENTIAL I REVIS ION I I I I I Browns Ferry Uni t 2 I Y I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17) |
| | VI. ADDITIONAL INFORMATION 2A seal spring holder assembly. |
| | B. v None. |
| | VII. COMMIXNEHTS None. |
| | Energy Industry Identification System (EIIS) system and component codes are identified in the text with brackets (e.g., [XX]). |
| | NRC Form 366(6-09) |
|
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| NRC Form 366 (6-09)FACILITY NAHE (1)r wn rr N 1 r P NUCLEAR REGULATORY COttlISSION LICENSEE EVENT REPORT (LER)Approved OHB No.3150-0104 Expires 4/30/92 IDOCKET NUMBER (TITLE (4)Reactor Shutdown Due To Recirculation Pump Seal Leakage.V T D I I I I I SEQUENTIAL I IREVISIONI I I I FACILITY NAHES N 0 I I I I I I I I I I I IDOCKET NUHBER(S)OPERATING NODE I ITHIS REPORT IS SUBHITTED PURSUANT TO THE REQUIREHENTS OF 10 CFR 5: I I w POWER I LEVEL I N I20.402(b)
| | r 4}} |
| I20.405(a)(l)(i)I20.405(a)(l)(ii)I20.405(a)(l)(iii)I20.405(a)(l)(iv).4 1 v IZ0.405(c)
| |
| I-ISO 36(c)(1)I50.36(c)(2)
| |
| I~I50.73(a)(2)(i)
| |
| I50.73(a)(2)(ii) 1 I50.73(a)(2)(iv)
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| I73.71(b)I50.73(a)(2)(v)
| |
| I73.71(c)I50.73(a)(2)(vii)
| |
| IOTHER (Specify in I50.73(a)(2)(viii)(A)
| |
| I Abstract below and'n I50.73(a)(2)(viii)(B)
| |
| I Text, NRC Form 366A)T.n'm li n i n i r N F P NT I AREA CODE I I Y T I I 0 P I I N N F IREPORTABLEI IREPORTABLEI I I PP N P I SUBHISSION I I I f m 1 D ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines)(16)On May 27, 1993, at 2015 hours, while operating at approximately eight percent power in the run mode following the BFN Unit 2 refueling outage, the Number 2 mechanical seal for the 2A Reactor Recirculation pump failed and the pump was removed from service.The Limiting Condition for Operation for Technical Specification 3.6.F.1 (TS)was entered which requires the plant be placed in a hot shutdown condition within 24 hours after taking one recirculation loop out of service.At 2225, an orderly plant shutdown was initiated in accordance with TS requirements.
| |
| On May 28, at 0140, plant shutdown was completed in an orderly manner.This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(A) as a condition that resulted in manual shutdown of the plant required by the plant's TS.The root cause of the recirculation pump seal failure was due to inadequate procedures.
| |
| An investigation of this event determined that the pump seal failed due to a small amount of loose particles (e.g., welding related material)collecting in the seal spring packing assembly causing the spring to jam and the seal not to seat properly.To prevent this problem from recurring, TVA revised site procedures to require seal purge flow to be established, to supply water to the seal cavity before opening the recirculation pump isolation valves following maintenance activities.
| |
| NRC Form 366(6-89)
| |
| ~I NRC Form 366A (6-89)U.S.NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)TEXT CONTINUATION Approved OHB No.3150-0104 Expires 4/30/92 FACIL'ITY NAME (1)Browns Ferry Uni t 2 IDOCKET NUMBER (2)I I I I SEQUENTIAL I I REVI S ION I I I I I I 8 I I I I TEXT (If more space is required, use additional NRC Form 366A's)(17)I.PLANT CONDITIONS Unit 2 was in the run mode at approximately eight percent power following the Cycle 6 refueling outage.Units 1 and 3 were shutdown and in a defueled condition.
| |
| II-DESCRIPTION OF EVENT A.~~at: On May 27', 1993, Operations personnel in the control room received indication of an abnormal seal pressure on the 2A recirculation
| |
| [AD]pump's number 2 seal.An inspection team entered the drywell at 1945 to check the recirculation pump seal alarm and to check for leakage.While the inspection team was in the drywell, the number 2 seal on the 2A recirculation pump started leaking excessively (approximately 5 gpm).Control room personnel were notified at 2013 of the leaking seal.At 2015 the 2A Reactor Recirculation System pump was removed from service and Technical Specification (TS)Limiting Condition for Operation (LCO)3.6.F.l was entered.This TS section requires the plant be placed in a hot shutdown condition within 24 hours after taking one recirculation loop out of service.At 2225, an orderly plant shutdown was initiated in accordance with TS 3.6.F.l.Since replacement of the recirculation pump seal could not be performed within the TS LCO, Unit 2 was shutdown and an Unusual Event (UE)was declared.On May 28, at 0140, the UE was terminated after all control rods were inserted and the mode switch was placed in the shutdown position.Subsequent investigation by TVA and representatives from the recirculation pump manufacturer determined that the cause of the seal leak was due to small particles in the recirculation system inhibiting the pump seal spring assembly.This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(A) due to the completion of plant shutdown required by TS requirements.
| |
| NRC Form 366(6-'89)
| |
| I J NRC Form 366A (6-89)U..NUCLEAR REGULATORY COHHISSION LICENSEE EVENT REPORT (LER)TEXT CONTINUATION Approved OHB No.3150-0104 Expires 4/30/92 FACILITY NAHE (1)Browns Ferry Uni t 2 IOOCKET.NUHBER (2)I I ISE()UENTIAL I IREYISIONI I I I I I I I I F TEXT (If more space is required, use additiona1 NRC Form 366A's)(17)B.Ia t t t t t t t h None.C.May 27, 1993, at 2015 CDT 2A Reactor Recirculation System pump removed from service due to seal leakage and entered 24-hour LCO.May 27, 1993, at 2225 CDT Initiated shutdown of Unit 2 reactor to cold shutdown, declared UE, and notified NRC within one hour of event in-accordance with 10 CFR 50.72(a)(3) and 50.72(b)(l)(i)(A).
| |
| May 28, 1993, at 0140 CDT UE terminated after all control rods were inserted and mode switch placed in shutdown'osition.
| |
| D.th None.E'h V e Abnormal Reactor Recirculation System.pump seal pressure indication in the control room alerted Operations personnel.
| |
| Operations personnel responded to the abnormal Reactor Recirculation System pump seal pressure indication by sending an inspection team into the drywell to check the pump seal alarm and for any seal leakage.Unit 2 was shutdown in an orderly fashion, due to the 2A Reactor Recirculation System pump's number 2 seal leaking excessively, as required by the plant's TS.G.None.NRC Form 366(6-89) 0 C NRC Form'366A (6-89)U..NUCLEAR REGULATORY COMMISSION
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| 'LICENSEE EVENT REPORT (LER)TEXT CONTINUATION Approved OMB No.3150-0104 Expires 4/30/92 FACILITY NAME (1)Browns Ferry Uni t 2 (OOCKET,NUMBER (2)I I PA i SE()VENT IAL i i REVISION (I I I I TEXT (If more space is required, use additional NRC Form 366A's)(17)III.CAUSE OF THE EVENT The immediate cause of the event was excessive leakage past the 2A Reactor Recirculation System pump mechanical seal.B.@~tstgI~: The root cause of the event was inadequate procedures.
| |
| Specifically, plant procedures failed to require seal purge flow to be established, prior to restarting the recirculation pumps, to supply water to the seal cavity prior to opening the recirculation pump isolation valves following maintenance activities.
| |
| Opening the recirculation pump valves prior to establishing seal purge flow allowed small particles to enter the seal spring assembly, which resulted in the pump seal leakage.An investigation performed by TVA and vendor personnel subsequent to the event determined that the pump seal failed due to a small amount of loose particles collecting in the seal spring packing assembly causing the spring to jam.The function of the seal spring packing assembly is to hold, the rotating face and carbon stationary face of the seal together.Very small amounts of debris in the spring assembly will cause the assembly to-malfunction.
| |
| Jamming of the spring assembly caused the seal not to seat properly, which resulted in the excessive leakage.The loose particles collected from the seal assembly were sent to Southwest.Research Laboratory for material characterization.
| |
| The laboratory results indicated that the average size of the particles was.008 square inches.The particle sizes ranged from.02 to.0016 square inches.The particles were determined to be weld related materials (i.e., iron particles and slag).C.The reactor vessel piping decontamination activities disturbed existing particles in the Reactor Recirculation System during the Unit 2, Cycle 6 refueling outage.The age and the origin of these particles are not known.NRC Form 366(6-89)
| |
| ~i NRC Form 366A (6-09)U..NUCLEAR REGULATORY COHHISSION LICENSEE EVENT REPORT (LER)TEXT CONTINUATION Approved OHB No.3150-0104 Expires 4/30/92 FACILITY NAME-(1)Browns Ferry Unit 2 IDOCKET NUHBER (2)I I I I SEqUENTIAL I I REVISIONI I I I I I A I I I I TEXT (If more space is required, use additional NRC Form 366A's)(17)C IV.ANALYSIS OF THE EVENT This event occurred with Unit 2 in the run mode at approximately eight percent power following the BFN Unit 2 refueling outage.Units 1 and 3 were shutdown and in a defueled condition.
| |
| Drywell leakage increased and the seal pressure equalized across the two stages, alerting the operators of a recirculation pump seal malfunction.
| |
| The pump leakage was calculated to be approximately 5.66 gpm during the shutdown process.'he seal construction is such that even during catastrophic seal failure, the maximum leakage is limited to approximately 60 gpm by the breakdown bushing with minimal impact on the containment pressure.At no time during the event was any safety system challenged.
| |
| No safety consequences resulted from the event, since the affected systems responded properly to perform their intended safety functions.
| |
| Therefore, the plant and the public safety was not adversely affected and the safety of the plant personnel was not compromised.
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| The mode switch was placed in"Shutdown" on May 28, 1993, at 0140 hours and the condition of cold shutdown was achieved.V.CORRECTIVE ACTIONS t v t'TVA personnel and representatives from the recirculation pump manufacturer disassembled the pump seal and inspected the mechanical seal assembly to determine cause of the leakage.B.tv At t TVA revised Operation Instruction 2-0I-68,"Reactor Recirculation System" to require seal purge flow to be established, prior to restarting the recircul'ation pump, to supply water to the seal cavity before opening the recirculation pump isolation valves following maintenance activities.
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| Specifically, this revision requires that CRD purge flow be turned on before the suction or discharge valves are opened after any maintenance that requires draining the pump cavity.Maintenance Instruction MCI-068-PMP001,"Maintenance of Reactor Recirculation Pumps," was revised to require seal flow to be on following seal maintenance activities before the suction or discharge valves are opened.These procedure requirements will prevent the loose particles from collecting in the pump seal spring assembly.NRC Form 366(6-89) 0 NRC Form 366A (6-09)U..NUCLEAR REGULATORY COHHISSION LICENSEE EVENT REPORT (LER)TEXT CONTINUATION Approved OHB No.3150-0104 Expires 4/30/92 FACILITY NAHE (1)Browns Ferry Uni t 2 iDOCKET NUHBER (2)I I, I I SEQUENTIAL I REVIS ION I I I I I I Y I I I I TEXT (If more space is required, use additional NRC Form 366A's)(17)VI.ADDITIONAL INFORMATION 2A seal spring holder assembly.B.v None.VII.COMMIXNEHTS None.Energy Industry Identification System (EIIS)system and component codes are identified in the text with brackets (e.g.,[XX]).NRC Form 366(6-09) r 4}}
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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML18039A9041999-10-15015 October 1999 LER 99-010-00:on 990917,automatic Reactor Scram on Turbine Stop Valve Closure Occurred.Caused by High Water Level in Main Steam Moisture Separator 2C2.Unit 2C2 Reservoir Level Transmitter & Relays Were Replaced & Tested Satisfactorily ML18039A8981999-10-14014 October 1999 LER 99-009-00:on 990915,manual Reactor Scram Was Noted Due to EHC Leak.Caused by Failure of Stainles Steel Tubing Connection.Removed Damaged Tubing & Connection Plug ML18039A8951999-10-0808 October 1999 LER 99-008-00:on 990905,HPCI Was Inoperable Due to Failed Flow Controller.Caused by Premature Failure of Capacitor 2C3.Replaced Controller & HPCI Sys Was Run IAW Sys Operating Instructions ML18039A8751999-09-30030 September 1999 LER 99-005-00:on 990901,SR for Standby Liquid Control Sampling Was Not Met.Caused by Deficient Procedure for Chemical Addition to Standby Liquid Control.Revised Procedure.With 990930 Ltr ML18039A8201999-07-26026 July 1999 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 ML18039A8171999-07-20020 July 1999 LER 99-007-00:on 990623,discovered That SR for Monitoring of Primary Containment Oxygen Concentration Had Not Been Met. Caused by Failure of Operators to Adequately Communicate. Required Surveillances Were Performed.With 990720 Ltr ML18039A8161999-07-19019 July 1999 LER 99-006-00:on 990618,noted That Main Steam SRV Exceeded TS Setpoint Tolerance.Caused by Pilot Vlve disc-seat Bonding.Util Replaced All 13 SRV Pilot Cartridges with Cartridges Certified to Be Witin +/-1%.With 990719 Ltr ML18039A8121999-07-12012 July 1999 LER 99-005-00:on 990617,ESF Actuation & HPCI Declared Inoperable.Caused by Personnel Error.Reset HPCI & Returned Sys to Operable Status with 25 Minutes.With 990712 Ltr ML18039A8101999-06-28028 June 1999 LER 99-004-00:on 990530,safety Features Sys Actuations Occurred Due to RPS Trip.Caused by Failure of MG Set AC Drive Motor Starter Contractor Coil.Licensee Placed 2B RPS Bus on Alternate Feed & Half Scram Was Reset ML18039A8011999-06-14014 June 1999 LER 99-001-00:on 990515,automatic Reactor Scram Occurred Due to Tt.Caused by Failure of Mechanical Trip Cylinder to Latch When Hydraulically Reset.Operations Crew Stabilized Reactor Following Scram.With 990614 Ltr ML18039A8021999-06-14014 June 1999 LER 99-002-00:on 990501,SRs for Single CR Withdrawal During Cold SD Were Not Adequately Implemented.Caused by Procedural Inadequacy.Revised Applicable Plant Surveillances.With 990614 Ltr ML18039A8071999-06-14014 June 1999 LER 99-003-00:on 990515,automatic Reactor Scram Due to Turbine Trip Was Noted.Caused by Failure of Mechanical Trip Cylinder to Latch When Hydraulically Reset.Operations Crew Stabilized Reactor Following Scram ML18039A7791999-05-0606 May 1999 LER 99-003-00:on 990408,declared Plant HPCI Sys Inoperable Due to Loose Wire.Caused by Failure to Properly Tighten Screw at Some Time in Past.Loose Wire Was Tightened ML18039A7461999-04-0707 April 1999 LER 99-001-00:on 990308,determined That Two Trains of Standby Gas Treatment (SGT) Were Inoperable.Caused by Trip C SGT Blower Motor Breaker.Initiated Shutdown of Plant,Reset C SGT Blower Motor Breaker & Declared Train Operable ML18039A6951999-02-19019 February 1999 LER 99-002-00:on 990122,LCO Was Not Entered During Calibration Testing of 3D 480 Volt Rmov Board.Caused by Personnel Error.Tva Has Briefed Operations Personnel to Preclude Recurrence of Event.With 990219 Ltr ML18039A6871999-02-12012 February 1999 LER 99-001-00:on 990114,Unit 3 HPCI Was Noted Inoperable. Caused by Oil Leak on Stop Valve.Corrective Maint Was Performed to Repair Oil Leak.With 990212 Ltr ML18039A6671998-12-31031 December 1998 LER 98-004-00:on 981202,SR Intent Was Not Adequately Implemented.Caused by Procedural Inadequacy.Revised Procedures to Provide Proper SR Implementation.With 981231 Ltr ML18039A6471998-12-15015 December 1998 LER 98-007-00:on 981116,unplanned ESF Following Loss of 4kV Unit Board 3B Occurred.Caused by Temporary Energization of Lockout Relay on 4kV Unit Board 3B When Resistor on Relay Monitoring Lamp Circuit Shorted.Replaced Resistor ML18039A6371998-12-0707 December 1998 LER 98-006-00:on 981116,MSSR Valves Exceeded TS Setpoint Tolerance.Caused by Pilot Valve Disc/Seat Bonding. Installed SRV Pressure Switches During Unit 3,cycle 8 Outage.With 981207 Ltr ML18039A6071998-11-12012 November 1998 LER 98-005-00:on 981014,mode Changes Not Allowed by TS 3.0.4 Were Made During Reactor Startup.Caused by TS LCO 3.0.4 Not Being Properly Applied.Training Info Memo Re Proper Application for TS LCO 3.0.4 Was Prepared.With 981112 Ltr ML18039A6031998-11-0404 November 1998 LER 98-004-00:on 981007,primary Containment Allowable Leak Rate Was Exceeded.Caused by Failure of Check Valve to Fully Seat Following Shutdown of Rbbccw Sys for Llrt.Valve Was Retested During Next Refueling Outage.With 981104 Ltr ML18039A5971998-10-28028 October 1998 LER 98-003-00:on 981001,Unit 2 Received Full Automatic Scram from 100% Reactor Power.Caused by Failure of Normally Open Isolation Valve Which Blocked Flow of Stator Cooling Water Through Associated Heat Exchangers.Replaced Failed Valve ML18039A5171998-09-15015 September 1998 LER 98-002-00:on 980816,personnel Observed Both Channels of Rod Block Monitor Sys Bypassed for Cr.Caused by Failure of Gene to Properly Document & Specify Adjustments.Will Implement Necessary Procedure Controls ML18039A3311998-05-0404 May 1998 LER 98-003-00:on 980407,reactor Manually Scrammed to Prevent thermal-hydraulic Instability After Recirculation Pump Runback.Caused by Human Error.Strengthened Controls Associated W/Walkdowns in NEDP-11 ML18039A3141998-04-0909 April 1998 LER 98-002-00:on 980310,ESF Actuation Occurred Due to Failure of Alternate Feeder Breaker Position Switch.Will Continue Testing & Visual Insps on Addl Breaker Position Switches & Will Revise Applicable Maint Instructions ML18039A3101998-04-0707 April 1998 LER 98-001-00:on 980308,ESF Actuations Occurred When 2B RPS Bus Was Transferred to de-energized Source.Caused by Failure of Preparing Clearance to Exercise Proper Attention. 2B RPS Bus Restored to Transformer Source ML18039A3051998-04-0101 April 1998 LER 96-001-00:on 980121,determined That Temp Sensors for Certain HELB May Not Detect All Possible Break Locations. Caused by Differences in Computer Codes Rather than Actual Response.Computer Code Correctly Utilized ML18039A2041997-12-0303 December 1997 LER 97-008-00:on 971104,main Steam Safety/Relief Valves Exceeded TS Setpoint Limit.Caused by Pilot Valve Disc/Seat Bonding.Replaced All 13 Unit 2 Main Steam SRV Pilot Cartridges ML18038B9961997-11-25025 November 1997 LER 97-007-00:on 971028,Unit 2 Automatically Scrammed.Caused by Momentary Pressure Drop in electro-hydraulic Control Sys at Turbine Control Valves.Scram Contactor Replaced ML18038B9931997-11-18018 November 1997 LER 97-006-00:on 971019,declared Unit 2 Hpcis Inoperable. Caused by High Condensate Level in HPCI Turbine Inlet Steam Line Drain Pot.Work Request Initiated ML18038B9861997-11-10010 November 1997 LER 97-005-00:on 971012,ESF Components Were Actuated.Caused by Inadequate Procedure.Cs Pumps Were Secured & Injection Valves Were Closed & Refueling Floor Activities Were Stopped ML18038B9701997-10-0909 October 1997 LER 97-004-00:on 970909,TS Surveillances Were Not Performed During Refueling Outage Timeframe.Caused by Personnel Error. Incorporated Missed Snubber & Vacuum Breaker Surveillances Into Refueling Outage Schedule ML18038B9661997-10-0303 October 1997 LER 97-005-00:on 970824,LCO Was Not Entered When Valve Was Malfunctioning.Caused by Lack of Questioning Attitude by Operations Crew.Involved SROs Were Counseled & Problem Evaluation Rept Will Be Discussed ML18038B9321997-08-0707 August 1997 LER 97-003-00:on 970711,determined That HPCI Turbine Speed Lower than Indicated.Caused by Improper Evaluation of Valve Leak.Work Orders to Troubleshoot HPCI Initiated ML18038B9231997-07-25025 July 1997 LER 97-002-00:on 970626,discovered That Four Surveillance Instructions (Sis) Did Not Fully Test All Relay Logic Combinations.Caused by Personnel Error.Verified Relay Contacts Operable & Revised Applicable SIs.W/970725 Ltr ML18038B8811997-05-14014 May 1997 LER 97-004-00:on 970414,unplanned Manual Start of EDG During Scheduled Redundant Start Test Occurred.Caused by Personnel Error.Edg 3D Shutdown & Returned to pre-event Configuration. W/970514 Ltr ML18038B8801997-05-0808 May 1997 LER 97-002-00:on 970410,HPCI Declared Inoperable.Caused by Personnel Error.Operations Personnel Stopped Instrument Mechanics Testing & Returned HPCI to Standby Readiness. W/970508 Ltr ML18038B8701997-04-29029 April 1997 LER 96-004-02:on 960717,loss of ECCS Division I & Division II Instrumentation Renders ECCS Equipment Inoperable.Caused by Loss of Inverter Output.Failed Components Replaced in Atu Inverter Circuitry & Instrumentation Logic Restored ML18038B8521997-04-0909 April 1997 LER 97-003-00:on 970314,Unit 3 Main Steam SRVs Pilot Cartridges Failed Setpoint Tolerance Bench Tests.Caused by Corrosion Bonding of SRV Pilot Disc/Seat Interface Resulting in Drifting.Main Steam SRV Pilot replaced.W/970409 Ltr ML18038B8511997-04-0909 April 1997 LER 95-003-02:on 950301,Unit 2 Main Steam SRVs Failed Setpoint Acceptance Tests.Caused by Corrosion Bonding of SRV Pilot Disc/Seat Interface Resulting in Upward Setpoint Drift.Valves Currently Being Retested & Recertified ML18038B8481997-04-0909 April 1997 LER 96-004-01:on 960425,Unit 2 SRV Pilot Cartridges Failed Setpoint Acceptance Tests.Caused by SRV Pilot Disc/Seat Bonding Resulting in SRV Setpoints Deviating.Valves Currently Being Retested & Recertified ML18038B8451997-04-0909 April 1997 LER 96-008-01:on 961101,Unit 2 Main Steam SRV Pilot Cartridges Failed Setpoint Tolerence Bench Tests.Caused by SRV Pilot Disc/Seat Bonding Resulting in SRV Setpoints.Srv Pilot Cartridges replaced.W/970409 Ltr ML18038B8551997-04-0404 April 1997 LER 97-001-00:on 970305,loss of Offsite Power on Unit 3 During Refueling Outage Resulted from Shorted Component. Replaced Relays Involved in Event W/Less Sensitive Relays ML18038B8441997-03-26026 March 1997 LER 95-001-02:on 950123,DG Turbocharger Failure Resulted in Noncompliance W/Ts Lco.Instituted Vibration Monitoring Program for EDG Turbochargers ML18038B8071997-01-15015 January 1997 LER 96-008-00:on 961217,loss of ECCS Division II Instrumentation Caused ECCS Equipment to Be Inoperable. Replaced Cleared Fuse & Shorted SCR ML18038B8041997-01-13013 January 1997 LER 96-007-00 on 961213,engineered Safety Feature Actuations Resulting from Inadequate Planning of step-text Work Order Occurred.Tripped Breaker Reset & LCO Condition Exited ML18038B7931996-12-0404 December 1996 LER 96-006-00:on 961106,loss of ECCS Div 1 Instrumentation Rendered ECCS Equipment Inoperable.Caused by Cleared Fuse in ECCS Div.Fuse Replaced & Addl Testing to Challenge Replacement Fuse performed.W/961204 Ltr ML18038B7921996-11-27027 November 1996 LER 96-008-00:on 961101,MS SR Valves Exceeded TS Required Setpoint Limit as Result of Disc/Seat Bonding.Caused by Corrosion Bonding of SRV Pilot Interface.Replaced All Thirteen Ms SR Valve Pilot cartridges.W/961127 Ltr ML18038B7911996-11-27027 November 1996 LER 96-007-00:on 961029,Unit 2 Scram on Turbine Control Valve Fast Closure Occurred Due to Loss of Excitation to Main Generator.Exciter Brushes Inspected & Replaced & Procedures Revised ML18038B7741996-10-15015 October 1996 LER 96-005-03:on 960915,reactor Scrammed as Required by TSs Due to Trip of Reactor Recirculation Motor Generator Set 3A. Caused by Bus Bar in Generator Armature Circuit Failing. Collector Rings Were replaced.W/961015 Ltr 1999-09-30
[Table view] Category:RO)
MONTHYEARML18039A9041999-10-15015 October 1999 LER 99-010-00:on 990917,automatic Reactor Scram on Turbine Stop Valve Closure Occurred.Caused by High Water Level in Main Steam Moisture Separator 2C2.Unit 2C2 Reservoir Level Transmitter & Relays Were Replaced & Tested Satisfactorily ML18039A8981999-10-14014 October 1999 LER 99-009-00:on 990915,manual Reactor Scram Was Noted Due to EHC Leak.Caused by Failure of Stainles Steel Tubing Connection.Removed Damaged Tubing & Connection Plug ML18039A8951999-10-0808 October 1999 LER 99-008-00:on 990905,HPCI Was Inoperable Due to Failed Flow Controller.Caused by Premature Failure of Capacitor 2C3.Replaced Controller & HPCI Sys Was Run IAW Sys Operating Instructions ML18039A8751999-09-30030 September 1999 LER 99-005-00:on 990901,SR for Standby Liquid Control Sampling Was Not Met.Caused by Deficient Procedure for Chemical Addition to Standby Liquid Control.Revised Procedure.With 990930 Ltr ML18039A8201999-07-26026 July 1999 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 ML18039A8171999-07-20020 July 1999 LER 99-007-00:on 990623,discovered That SR for Monitoring of Primary Containment Oxygen Concentration Had Not Been Met. Caused by Failure of Operators to Adequately Communicate. Required Surveillances Were Performed.With 990720 Ltr ML18039A8161999-07-19019 July 1999 LER 99-006-00:on 990618,noted That Main Steam SRV Exceeded TS Setpoint Tolerance.Caused by Pilot Vlve disc-seat Bonding.Util Replaced All 13 SRV Pilot Cartridges with Cartridges Certified to Be Witin +/-1%.With 990719 Ltr ML18039A8121999-07-12012 July 1999 LER 99-005-00:on 990617,ESF Actuation & HPCI Declared Inoperable.Caused by Personnel Error.Reset HPCI & Returned Sys to Operable Status with 25 Minutes.With 990712 Ltr ML18039A8101999-06-28028 June 1999 LER 99-004-00:on 990530,safety Features Sys Actuations Occurred Due to RPS Trip.Caused by Failure of MG Set AC Drive Motor Starter Contractor Coil.Licensee Placed 2B RPS Bus on Alternate Feed & Half Scram Was Reset ML18039A8011999-06-14014 June 1999 LER 99-001-00:on 990515,automatic Reactor Scram Occurred Due to Tt.Caused by Failure of Mechanical Trip Cylinder to Latch When Hydraulically Reset.Operations Crew Stabilized Reactor Following Scram.With 990614 Ltr ML18039A8021999-06-14014 June 1999 LER 99-002-00:on 990501,SRs for Single CR Withdrawal During Cold SD Were Not Adequately Implemented.Caused by Procedural Inadequacy.Revised Applicable Plant Surveillances.With 990614 Ltr ML18039A8071999-06-14014 June 1999 LER 99-003-00:on 990515,automatic Reactor Scram Due to Turbine Trip Was Noted.Caused by Failure of Mechanical Trip Cylinder to Latch When Hydraulically Reset.Operations Crew Stabilized Reactor Following Scram ML18039A7791999-05-0606 May 1999 LER 99-003-00:on 990408,declared Plant HPCI Sys Inoperable Due to Loose Wire.Caused by Failure to Properly Tighten Screw at Some Time in Past.Loose Wire Was Tightened ML18039A7461999-04-0707 April 1999 LER 99-001-00:on 990308,determined That Two Trains of Standby Gas Treatment (SGT) Were Inoperable.Caused by Trip C SGT Blower Motor Breaker.Initiated Shutdown of Plant,Reset C SGT Blower Motor Breaker & Declared Train Operable ML18039A6951999-02-19019 February 1999 LER 99-002-00:on 990122,LCO Was Not Entered During Calibration Testing of 3D 480 Volt Rmov Board.Caused by Personnel Error.Tva Has Briefed Operations Personnel to Preclude Recurrence of Event.With 990219 Ltr ML18039A6871999-02-12012 February 1999 LER 99-001-00:on 990114,Unit 3 HPCI Was Noted Inoperable. Caused by Oil Leak on Stop Valve.Corrective Maint Was Performed to Repair Oil Leak.With 990212 Ltr ML18039A6671998-12-31031 December 1998 LER 98-004-00:on 981202,SR Intent Was Not Adequately Implemented.Caused by Procedural Inadequacy.Revised Procedures to Provide Proper SR Implementation.With 981231 Ltr ML18039A6471998-12-15015 December 1998 LER 98-007-00:on 981116,unplanned ESF Following Loss of 4kV Unit Board 3B Occurred.Caused by Temporary Energization of Lockout Relay on 4kV Unit Board 3B When Resistor on Relay Monitoring Lamp Circuit Shorted.Replaced Resistor ML18039A6371998-12-0707 December 1998 LER 98-006-00:on 981116,MSSR Valves Exceeded TS Setpoint Tolerance.Caused by Pilot Valve Disc/Seat Bonding. Installed SRV Pressure Switches During Unit 3,cycle 8 Outage.With 981207 Ltr ML18039A6071998-11-12012 November 1998 LER 98-005-00:on 981014,mode Changes Not Allowed by TS 3.0.4 Were Made During Reactor Startup.Caused by TS LCO 3.0.4 Not Being Properly Applied.Training Info Memo Re Proper Application for TS LCO 3.0.4 Was Prepared.With 981112 Ltr ML18039A6031998-11-0404 November 1998 LER 98-004-00:on 981007,primary Containment Allowable Leak Rate Was Exceeded.Caused by Failure of Check Valve to Fully Seat Following Shutdown of Rbbccw Sys for Llrt.Valve Was Retested During Next Refueling Outage.With 981104 Ltr ML18039A5971998-10-28028 October 1998 LER 98-003-00:on 981001,Unit 2 Received Full Automatic Scram from 100% Reactor Power.Caused by Failure of Normally Open Isolation Valve Which Blocked Flow of Stator Cooling Water Through Associated Heat Exchangers.Replaced Failed Valve ML18039A5171998-09-15015 September 1998 LER 98-002-00:on 980816,personnel Observed Both Channels of Rod Block Monitor Sys Bypassed for Cr.Caused by Failure of Gene to Properly Document & Specify Adjustments.Will Implement Necessary Procedure Controls ML18039A3311998-05-0404 May 1998 LER 98-003-00:on 980407,reactor Manually Scrammed to Prevent thermal-hydraulic Instability After Recirculation Pump Runback.Caused by Human Error.Strengthened Controls Associated W/Walkdowns in NEDP-11 ML18039A3141998-04-0909 April 1998 LER 98-002-00:on 980310,ESF Actuation Occurred Due to Failure of Alternate Feeder Breaker Position Switch.Will Continue Testing & Visual Insps on Addl Breaker Position Switches & Will Revise Applicable Maint Instructions ML18039A3101998-04-0707 April 1998 LER 98-001-00:on 980308,ESF Actuations Occurred When 2B RPS Bus Was Transferred to de-energized Source.Caused by Failure of Preparing Clearance to Exercise Proper Attention. 2B RPS Bus Restored to Transformer Source ML18039A3051998-04-0101 April 1998 LER 96-001-00:on 980121,determined That Temp Sensors for Certain HELB May Not Detect All Possible Break Locations. Caused by Differences in Computer Codes Rather than Actual Response.Computer Code Correctly Utilized ML18039A2041997-12-0303 December 1997 LER 97-008-00:on 971104,main Steam Safety/Relief Valves Exceeded TS Setpoint Limit.Caused by Pilot Valve Disc/Seat Bonding.Replaced All 13 Unit 2 Main Steam SRV Pilot Cartridges ML18038B9961997-11-25025 November 1997 LER 97-007-00:on 971028,Unit 2 Automatically Scrammed.Caused by Momentary Pressure Drop in electro-hydraulic Control Sys at Turbine Control Valves.Scram Contactor Replaced ML18038B9931997-11-18018 November 1997 LER 97-006-00:on 971019,declared Unit 2 Hpcis Inoperable. Caused by High Condensate Level in HPCI Turbine Inlet Steam Line Drain Pot.Work Request Initiated ML18038B9861997-11-10010 November 1997 LER 97-005-00:on 971012,ESF Components Were Actuated.Caused by Inadequate Procedure.Cs Pumps Were Secured & Injection Valves Were Closed & Refueling Floor Activities Were Stopped ML18038B9701997-10-0909 October 1997 LER 97-004-00:on 970909,TS Surveillances Were Not Performed During Refueling Outage Timeframe.Caused by Personnel Error. Incorporated Missed Snubber & Vacuum Breaker Surveillances Into Refueling Outage Schedule ML18038B9661997-10-0303 October 1997 LER 97-005-00:on 970824,LCO Was Not Entered When Valve Was Malfunctioning.Caused by Lack of Questioning Attitude by Operations Crew.Involved SROs Were Counseled & Problem Evaluation Rept Will Be Discussed ML18038B9321997-08-0707 August 1997 LER 97-003-00:on 970711,determined That HPCI Turbine Speed Lower than Indicated.Caused by Improper Evaluation of Valve Leak.Work Orders to Troubleshoot HPCI Initiated ML18038B9231997-07-25025 July 1997 LER 97-002-00:on 970626,discovered That Four Surveillance Instructions (Sis) Did Not Fully Test All Relay Logic Combinations.Caused by Personnel Error.Verified Relay Contacts Operable & Revised Applicable SIs.W/970725 Ltr ML18038B8811997-05-14014 May 1997 LER 97-004-00:on 970414,unplanned Manual Start of EDG During Scheduled Redundant Start Test Occurred.Caused by Personnel Error.Edg 3D Shutdown & Returned to pre-event Configuration. W/970514 Ltr ML18038B8801997-05-0808 May 1997 LER 97-002-00:on 970410,HPCI Declared Inoperable.Caused by Personnel Error.Operations Personnel Stopped Instrument Mechanics Testing & Returned HPCI to Standby Readiness. W/970508 Ltr ML18038B8701997-04-29029 April 1997 LER 96-004-02:on 960717,loss of ECCS Division I & Division II Instrumentation Renders ECCS Equipment Inoperable.Caused by Loss of Inverter Output.Failed Components Replaced in Atu Inverter Circuitry & Instrumentation Logic Restored ML18038B8521997-04-0909 April 1997 LER 97-003-00:on 970314,Unit 3 Main Steam SRVs Pilot Cartridges Failed Setpoint Tolerance Bench Tests.Caused by Corrosion Bonding of SRV Pilot Disc/Seat Interface Resulting in Drifting.Main Steam SRV Pilot replaced.W/970409 Ltr ML18038B8511997-04-0909 April 1997 LER 95-003-02:on 950301,Unit 2 Main Steam SRVs Failed Setpoint Acceptance Tests.Caused by Corrosion Bonding of SRV Pilot Disc/Seat Interface Resulting in Upward Setpoint Drift.Valves Currently Being Retested & Recertified ML18038B8481997-04-0909 April 1997 LER 96-004-01:on 960425,Unit 2 SRV Pilot Cartridges Failed Setpoint Acceptance Tests.Caused by SRV Pilot Disc/Seat Bonding Resulting in SRV Setpoints Deviating.Valves Currently Being Retested & Recertified ML18038B8451997-04-0909 April 1997 LER 96-008-01:on 961101,Unit 2 Main Steam SRV Pilot Cartridges Failed Setpoint Tolerence Bench Tests.Caused by SRV Pilot Disc/Seat Bonding Resulting in SRV Setpoints.Srv Pilot Cartridges replaced.W/970409 Ltr ML18038B8551997-04-0404 April 1997 LER 97-001-00:on 970305,loss of Offsite Power on Unit 3 During Refueling Outage Resulted from Shorted Component. Replaced Relays Involved in Event W/Less Sensitive Relays ML18038B8441997-03-26026 March 1997 LER 95-001-02:on 950123,DG Turbocharger Failure Resulted in Noncompliance W/Ts Lco.Instituted Vibration Monitoring Program for EDG Turbochargers ML18038B8071997-01-15015 January 1997 LER 96-008-00:on 961217,loss of ECCS Division II Instrumentation Caused ECCS Equipment to Be Inoperable. Replaced Cleared Fuse & Shorted SCR ML18038B8041997-01-13013 January 1997 LER 96-007-00 on 961213,engineered Safety Feature Actuations Resulting from Inadequate Planning of step-text Work Order Occurred.Tripped Breaker Reset & LCO Condition Exited ML18038B7931996-12-0404 December 1996 LER 96-006-00:on 961106,loss of ECCS Div 1 Instrumentation Rendered ECCS Equipment Inoperable.Caused by Cleared Fuse in ECCS Div.Fuse Replaced & Addl Testing to Challenge Replacement Fuse performed.W/961204 Ltr ML18038B7921996-11-27027 November 1996 LER 96-008-00:on 961101,MS SR Valves Exceeded TS Required Setpoint Limit as Result of Disc/Seat Bonding.Caused by Corrosion Bonding of SRV Pilot Interface.Replaced All Thirteen Ms SR Valve Pilot cartridges.W/961127 Ltr ML18038B7911996-11-27027 November 1996 LER 96-007-00:on 961029,Unit 2 Scram on Turbine Control Valve Fast Closure Occurred Due to Loss of Excitation to Main Generator.Exciter Brushes Inspected & Replaced & Procedures Revised ML18038B7741996-10-15015 October 1996 LER 96-005-03:on 960915,reactor Scrammed as Required by TSs Due to Trip of Reactor Recirculation Motor Generator Set 3A. Caused by Bus Bar in Generator Armature Circuit Failing. Collector Rings Were replaced.W/961015 Ltr 1999-09-30
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML18039A9041999-10-15015 October 1999 LER 99-010-00:on 990917,automatic Reactor Scram on Turbine Stop Valve Closure Occurred.Caused by High Water Level in Main Steam Moisture Separator 2C2.Unit 2C2 Reservoir Level Transmitter & Relays Were Replaced & Tested Satisfactorily ML18039A8981999-10-14014 October 1999 LER 99-009-00:on 990915,manual Reactor Scram Was Noted Due to EHC Leak.Caused by Failure of Stainles Steel Tubing Connection.Removed Damaged Tubing & Connection Plug ML18039A8951999-10-0808 October 1999 LER 99-008-00:on 990905,HPCI Was Inoperable Due to Failed Flow Controller.Caused by Premature Failure of Capacitor 2C3.Replaced Controller & HPCI Sys Was Run IAW Sys Operating Instructions ML18039A8751999-09-30030 September 1999 LER 99-005-00:on 990901,SR for Standby Liquid Control Sampling Was Not Met.Caused by Deficient Procedure for Chemical Addition to Standby Liquid Control.Revised Procedure.With 990930 Ltr ML20217F9671999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Browns Ferry Nuclear Plant,Units 1,2 & 3.With ML20212E6341999-09-23023 September 1999 Suppl to SE Resolving Error in Original 990802 Se,Clarifying Fact That Licensee Has Not Committed to Retain Those Specific Compensatory Measures That Were Applied to one-time Extension ML20212D3831999-09-20020 September 1999 Safety Evaluation Supporting Proposed Rev to Withdrawal Schedule for First & Third Surveillance Capsules for BFN-3 RPV ML20212B8561999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Browns Ferry Nuclear Plant.With ML18039A8821999-08-31031 August 1999 Increased MSIV Leakage Tech Spec Change Submittal - Seismic Evaluation Rept. ML18039A8391999-08-0606 August 1999 BFN Unit 2 Cycle 10 ASME Section XI NIS-1 & NIS-2 Data Repts. ML20210N1221999-08-0202 August 1999 Safety Evaluation Accepting Licensee Request for Relief from ASME B&PV Code,Section XI Requirements.Request 3-ISI-7, Pertains to Second 10-year Interval ISI for Plant,Unit 3 ML20210R0931999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Browns Ferry Nuclear Plant,Units 1,2 & 3.With ML18039A8201999-07-26026 July 1999 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 ML18039A8171999-07-20020 July 1999 LER 99-007-00:on 990623,discovered That SR for Monitoring of Primary Containment Oxygen Concentration Had Not Been Met. Caused by Failure of Operators to Adequately Communicate. Required Surveillances Were Performed.With 990720 Ltr ML18039A8161999-07-19019 July 1999 LER 99-006-00:on 990618,noted That Main Steam SRV Exceeded TS Setpoint Tolerance.Caused by Pilot Vlve disc-seat Bonding.Util Replaced All 13 SRV Pilot Cartridges with Cartridges Certified to Be Witin +/-1%.With 990719 Ltr ML20209J0771999-07-16016 July 1999 Safety Evaluation Concluding That Licensee Provided Adequate Information to Resolve ampacity-related Points of Concern Raised in GL 92-08 for BFN & That No Outstanding Issues Re GL 92-08 Ampacity Issues for Browns Ferry NPP Exist ML18039A8121999-07-12012 July 1999 LER 99-005-00:on 990617,ESF Actuation & HPCI Declared Inoperable.Caused by Personnel Error.Reset HPCI & Returned Sys to Operable Status with 25 Minutes.With 990712 Ltr ML20209H4381999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Browns Ferry Nuclear Plant,Units 1,2 & 3.With ML18039A8101999-06-28028 June 1999 LER 99-004-00:on 990530,safety Features Sys Actuations Occurred Due to RPS Trip.Caused by Failure of MG Set AC Drive Motor Starter Contractor Coil.Licensee Placed 2B RPS Bus on Alternate Feed & Half Scram Was Reset ML20196F8811999-06-23023 June 1999 Safety Evaluation Accepting GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power Operated Gate Valves ML18039A8071999-06-14014 June 1999 LER 99-003-00:on 990515,automatic Reactor Scram Due to Turbine Trip Was Noted.Caused by Failure of Mechanical Trip Cylinder to Latch When Hydraulically Reset.Operations Crew Stabilized Reactor Following Scram ML18039A8021999-06-14014 June 1999 LER 99-002-00:on 990501,SRs for Single CR Withdrawal During Cold SD Were Not Adequately Implemented.Caused by Procedural Inadequacy.Revised Applicable Plant Surveillances.With 990614 Ltr ML18039A8011999-06-14014 June 1999 LER 99-001-00:on 990515,automatic Reactor Scram Occurred Due to Tt.Caused by Failure of Mechanical Trip Cylinder to Latch When Hydraulically Reset.Operations Crew Stabilized Reactor Following Scram.With 990614 Ltr ML20196B8051999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Browns Ferry Nuclear Plant,Units 1,2 & 3.With ML18039A7791999-05-0606 May 1999 LER 99-003-00:on 990408,declared Plant HPCI Sys Inoperable Due to Loose Wire.Caused by Failure to Properly Tighten Screw at Some Time in Past.Loose Wire Was Tightened ML18039A7761999-04-30030 April 1999 Revised Surveillance Specimen Program Evaluation for TVA Browns Ferry Unit 3. ML20206R0731999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Bfnp.With ML18039A7561999-04-23023 April 1999 Bfnp Risk-Informed Inservice Insp (RI-ISI) Program Submittal. ML18039A7671999-04-0808 April 1999 Rev 0 to TVA-COLR-BF2C11, Browns Ferry Nuclear Plant Unit 2 Cycle 11 Colr. ML18039A7461999-04-0707 April 1999 LER 99-001-00:on 990308,determined That Two Trains of Standby Gas Treatment (SGT) Were Inoperable.Caused by Trip C SGT Blower Motor Breaker.Initiated Shutdown of Plant,Reset C SGT Blower Motor Breaker & Declared Train Operable ML20205N8341999-04-0101 April 1999 Part 21 Rept Re Automatic Switch Co Nuclear Grade Series X206380 & X206832 Solenoid Valves Ordered Without Lubricants That Were Shipped with Std Lubrication to PECO & Tva.Affected Plants Were Notified ML20205F9341999-04-0101 April 1999 Safety Evaluation Authorizing Licensee 990108 Relief Request PV-38,from Requirements of ASME BPV Code Section XI IST Testing,Valve Program for Plant,Units 1,2 & 3 ML20205T5441999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Bfnp.With ML20205S0601999-03-31031 March 1999 Rept on Status of Public Petitions Under 10CFR2.206 with Status Change from Previous Update,990331 ML20205S0661999-03-31031 March 1999 Rept on Status of Public Petitions Under 10CFR2.206 with No Status Change from Previous Update,990331, Atlas Corp ML18039A7361999-03-11011 March 1999 Rev 4 to TVA-COLR-BF2C10, Bfnp,Unit 2,Cycle 10 Colr. ML20204C7891999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Browns Ferry Nuclear Plant,Units 1,2 & 3.With ML18039A6951999-02-19019 February 1999 LER 99-002-00:on 990122,LCO Was Not Entered During Calibration Testing of 3D 480 Volt Rmov Board.Caused by Personnel Error.Tva Has Briefed Operations Personnel to Preclude Recurrence of Event.With 990219 Ltr ML18039A6871999-02-12012 February 1999 LER 99-001-00:on 990114,Unit 3 HPCI Was Noted Inoperable. Caused by Oil Leak on Stop Valve.Corrective Maint Was Performed to Repair Oil Leak.With 990212 Ltr ML18039A6931999-02-0303 February 1999 Rev 3 to TVA-COLR-BF2C10, Bfnp Unit 2 Cycle 10 Colr. ML18039A6941999-02-0303 February 1999 Rev 1 to TVA-COLR-BF3C9, Bfnp Unit 3 Cycle 9 Colr. ML18039A6671998-12-31031 December 1998 LER 98-004-00:on 981202,SR Intent Was Not Adequately Implemented.Caused by Procedural Inadequacy.Revised Procedures to Provide Proper SR Implementation.With 981231 Ltr ML18039A6661998-12-31031 December 1998 Ro:On 981215,HRPCRM 2-RM-90-273C Was Declared Inoperable. Caused by Downscale Indication.Containment RM Will Be Utilized as Planned Alternate Method of Monitoring Until Hrpcrm 2-RM-90-273C Can Be Returned to Operable Status ML20199K8951998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Browns Ferry Nuclear Plant.With ML20199F2721998-12-31031 December 1998 ISI Summary Rept (NIS-1), for BFN Unit 3,Cycle 8 Operation ML18039A6471998-12-15015 December 1998 LER 98-007-00:on 981116,unplanned ESF Following Loss of 4kV Unit Board 3B Occurred.Caused by Temporary Energization of Lockout Relay on 4kV Unit Board 3B When Resistor on Relay Monitoring Lamp Circuit Shorted.Replaced Resistor ML18039A6371998-12-0707 December 1998 LER 98-006-00:on 981116,MSSR Valves Exceeded TS Setpoint Tolerance.Caused by Pilot Valve Disc/Seat Bonding. Installed SRV Pressure Switches During Unit 3,cycle 8 Outage.With 981207 Ltr ML20199F2791998-12-0303 December 1998 Bfnp Unit 3 Cycle 8 ASME Section XI NIS-2 Data Rept ML20198D9621998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Bfn,Units 1,2 & 3. with ML18039A6071998-11-12012 November 1998 LER 98-005-00:on 981014,mode Changes Not Allowed by TS 3.0.4 Were Made During Reactor Startup.Caused by TS LCO 3.0.4 Not Being Properly Applied.Training Info Memo Re Proper Application for TS LCO 3.0.4 Was Prepared.With 981112 Ltr 1999-09-30
[Table view] |
Text
ACCEI.ERATED'OCUMENT DISTKKUTIONSYSTEM REGULA'ZOY INFORMATION DISTRIBUTIO!SYSTEM (RIDE)
ACCESSION NBR:9306300206 DOC.DATE: 93/06/23 NOTARIZED: NO DOCKET FACIL 50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH. NAME KNUETTEL,E.T.
'UTHOR AFFILIATION Tennessee Valley Authority ZERINGUE,O.J. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION'UBJECT:
LER 93-007-00:on 930527,mechanical seal for 2A reactor recirculation pump failed. Caused by inadequate procedures.
Site procedures revised to require seal purge flow to be established.W/930623 ltr.
DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:
TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.
NOTES:
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID- CODE/NAME LTTR ENCL PD2-4 1 1 PD2-4-PD 1 1 ROSS,T. 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DORS/OEAB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB .1 1 NRR/DRIL/RPEB 1 1 NRR/DRSS/PRPB 2 .
2 RR'/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 EG FILE 02 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL'G&G BRYCEF J ~ H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHYFG.A 1 1 NSIC POOREFW 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTEI CONTACI'HE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
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Tennessee Valley Autftority, Post Office Box 2000, Decatur, Alabama 35609.2000 O. J. "Ike" Zeringue Vice President. Browns Ferry Nuclear Plant June 23, 1993 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555
Dear Sir:
TVA BROWNS FERRY NUCLEAR PLANT (BFN) UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 260, AND 296 FACILITY OPERATING LICENSE DPR-33, 52, AND'8 LICENSEE EVENT REPORT 50-260/93007 The enclosed report provides details concerning a manual reactor shutdown due to a recirculation pump seal leak. This event occurred during startup from the Unit 2, Cycle 6 refueling outage.
This report is submitted in accordance with 10 CFR 50.'73(a)(2)(i)(A) due to the manual shutdown of the plant as required by technical specification.
requirements.
Sincerely,
- 0. J. Zeringue Enclosure cc: See page 2 rgu>
9306300206 930623 PDR ADOCK 05000260
-PDR
0 U.S. Nuclear Regulatory Commission June 23, 1993 cc (Enclosure):
INFO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 Paul Krippner American Nuclear Insurers Town Center, Suite .300S 29 South Main Street West Hartford, Connecticut 06107 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, P.O. Box 637 Athens, Alabama 35609-2000 Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 2900 Atlanta, Georgia 30323 Thierry, M. Ross U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852
NRC Form 366 NUCLEAR REGULATORY COttlISSION Approved OHB No. 3150-0104 (6-09) Expires 4/30/92 LICENSEE EVENT REPORT (LER)
FACILITY NAHE (1) IDOCKET NUMBER (
r wn rr N 1 r P TITLE (4) Reactor Shutdown Due To Recirculation Pump Seal Leakage.
V T D SEQUENTIAL I IREVISIONI I I I FACILITY NAHES IDOCKET NUHBER(S)
I I I I I N 0 I I I I I I I I I I I OPERATING I ITHIS REPORT IS SUBHITTED PURSUANT TO THE REQUIREHENTS OF 10 CFR 5:
NODE w I I N I20.402(b) IZ0.405(c) I50.73(a)(2)(iv) I73.71(b)
POWER I I20.405(a)( l)(i ) I ISO 36(c)(1) I50.73(a)(2)(v) I73.71(c)
LEVEL I20.405(a)( l)(ii) I50.36(c)(2) I50.73(a)(2)(vii) IOTHER (Specify in I
I20.405(a)( l)(iii ) I~I50.73(a)(2)(i) I50.73(a)(2)(viii)(A) I Abstract below and'n I20.405(a)( l)(iv) I50.73(a)(2)(ii) I50.73(a)(2)(viii)(B) I Text, NRC Form 366A)
.4 1 v 1 I AREA CODE T. n
'
m li n i n i r N F P NT IREPORTABLEI IREPORTABLEI I I Y T N N F I I I I 0 P I I PP N P I SUBHISSION I I I f m 1 D ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines) (16)
On May 27, 1993, at 2015 hours0.0233 days <br />0.56 hours <br />0.00333 weeks <br />7.667075e-4 months <br />, while operating at approximately eight percent power in the run mode following the BFN Unit 2 refueling outage, the Number 2 mechanical seal for the 2A Reactor Recirculation pump failed and the pump was removed from service. The Limiting Condition for Operation for Technical Specification 3.6.F.1 (TS) was entered which requires the plant be placed in a hot shutdown condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after taking one recirculation loop out of service. At 2225, an orderly plant shutdown was initiated in accordance with TS requirements. On May 28, at 0140, plant shutdown was completed in an orderly manner. This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(A) as a condition that resulted in manual shutdown of the plant required by the plant's TS.
The root cause of the recirculation pump seal failure was due to inadequate procedures. An investigation of this event determined that the pump seal failed due to a small amount of loose particles (e.g., welding related material) collecting in the seal spring packing assembly causing the spring to jam and the seal not to seat properly. To prevent this problem from recurring, TVA revised site procedures before to require seal purge flow to be established, to supply water to the seal cavity opening the recirculation pump isolation valves following maintenance activities.
NRC Form 366(6-89)
~I NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION Approved OHB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACIL'ITY NAME (1) IDOCKET NUMBER (2)
I I I I SEQUENTIAL I I REVI S ION I I I I I Browns Ferry Uni t 2 I 8 I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)
I. PLANT CONDITIONS Unit 2 was in the run mode at approximately eight percent power following the Cycle 6 refueling outage. Units 1 and 3 were shutdown and in a defueled condition.
II- DESCRIPTION OF EVENT A. ~~at:
On May 27', 1993, Operations personnel in the control room received indication of an abnormal seal pressure on the 2A recirculation [AD]
pump's number 2 seal. An inspection team entered the drywell at 1945 to check the recirculation pump seal alarm and to check for leakage. While the inspection team was in the drywell, the number 2 seal on the 2A recirculation pump started leaking excessively (approximately 5 gpm).
Control room personnel were notified at 2013 of the leaking seal. At 2015 the 2A Reactor Recirculation System pump was removed from service and Technical Specification (TS) Limiting Condition for Operation (LCO) 3.6.F.l was entered. This TS section requires the plant be placed in a hot shutdown condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after taking one recirculation loop out of service.
At 2225, an orderly plant shutdown was initiated in accordance with TS 3.6.F.l. Since replacement of the recirculation pump seal could not be performed within the TS LCO, Unit 2 was shutdown and an Unusual Event (UE) was declared. On May 28, at 0140, the UE was terminated after all control rods were inserted and the mode switch was placed in the shutdown position.
Subsequent investigation by TVA and representatives from the recirculation pump manufacturer determined that the cause of the seal leak was due to small particles in the recirculation system inhibiting the pump seal spring assembly.
This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(A) due to the completion of plant shutdown required by TS requirements.
NRC Form 366(6-'89)
I J
NRC Form 366A U. . NUCLEAR REGULATORY COHHISSION Approved OHB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAHE (1) IOOCKET. NUHBER (2)
I ISE()UENTIAL I IREYISIONI I I I I Browns Ferry Uni t 2 I I I I I F
TEXT (If more space is required, use additiona1 NRC Form 366A's) (17)
B. Ia t t t t t t t h None.
C.
May 27, 1993, at 2015 CDT 2A Reactor Recirculation System pump removed from service due to seal leakage and entered 24-hour LCO.
May 27, 1993, at 2225 CDT Initiated shutdown of Unit 2 reactor to cold shutdown, declared UE, and notified NRC within one hour of event in-accordance with 10 CFR 50.72(a)(3) and 50.72(b)(l)(i)(A).
May 28, 1993, at 0140 CDT UE terminated after all control rods were inserted and mode switch placed in shutdown'osition.
D. th None.
E 'h V e Abnormal Reactor Recirculation System. pump seal pressure indication in the control room alerted Operations personnel.
Operations personnel responded to the abnormal Reactor Recirculation System pump seal pressure indication by sending an inspection team into the drywell to check the pump seal alarm and for any seal leakage. Unit 2 was shutdown in an orderly fashion, due to the 2A Reactor Recirculation System pump's number 2 seal leaking excessively, as required by the plant's TS.
G.
None.
NRC Form 366(6-89)
0 C
NRC Form'366A U.. NUCLEAR REGULATORY COMMISSION Approved OMB No. 3150-0104 (6-89) Expires 4/30/92
'LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1) (OOCKET,NUMBER (2) PA I i SE()VENT IAL i i REVISION (
Browns Ferry Uni t 2 I I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)
III. CAUSE OF THE EVENT The immediate cause of the event was excessive leakage past the 2A Reactor Recirculation System pump mechanical seal.
B. @~tstgI~:
The root cause of the event was inadequate procedures. Specifically, plant procedures failed to require seal purge flow to be established, prior to restarting the recirculation pumps, to supply water to the seal cavity prior to opening the recirculation pump isolation valves following maintenance activities. Opening the recirculation pump valves prior to establishing seal purge flow allowed small particles to enter the seal spring assembly, which resulted in the pump seal leakage.
An investigation performed by TVA and vendor personnel subsequent to the event determined that the pump seal failed due to a small amount of loose particles collecting in the seal spring packing assembly causing the spring to jam. The function of the seal spring packing assembly is to hold, the rotating face and carbon stationary face of the seal together.
Very small amounts of debris in the spring assembly will cause the assembly to-malfunction. Jamming of the spring assembly caused the seal not to seat properly, which resulted in the excessive leakage.
The loose particles collected from the seal assembly were sent to Southwest .Research Laboratory for material characterization. The laboratory results indicated that the average size of the particles was
.008 square inches. The particle sizes ranged from .02 to .0016 square inches. The particles were determined to be weld related materials (i.e.,
iron particles and slag).
C.
The reactor vessel piping decontamination activities disturbed existing particles in the Reactor Recirculation System during the Unit 2, Cycle 6 refueling outage. The age and the origin of these particles are not known.
NRC Form 366(6-89)
~i NRC Form 366A U.. NUCLEAR REGULATORY COHHISSION Approved OHB No. 3150-0104 (6-09) Expires 4/30/92 LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME -(1) IDOCKET NUHBER (2)
I I I I SEqUENTIAL I I REVISIONI I I I I Browns Ferry Unit 2 I A I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)
C IV. ANALYSIS OF THE EVENT This event occurred with Unit 2 in the run mode at approximately eight percent power following the BFN Unit 2 refueling outage. Units 1 and 3 were shutdown and in a defueled condition.
Drywell leakage increased and the seal pressure equalized across the two stages, alerting the operators of a recirculation pump seal malfunction. The pump leakage was calculated to be approximately 5.66 gpm during the shutdown process.'he seal construction is such that even during catastrophic seal failure, the maximum leakage is limited to approximately 60 gpm by the breakdown bushing with minimal impact on the containment pressure. At no time during the event was any safety system challenged. No safety consequences resulted from the event, since the affected systems responded properly to perform their intended safety functions. Therefore, the plant and the public safety was not adversely affected and the safety of the plant personnel was not compromised. The mode switch was placed in "Shutdown" on May 28, 1993, at 0140 hours0.00162 days <br />0.0389 hours <br />2.314815e-4 weeks <br />5.327e-5 months <br /> and the condition of cold shutdown was achieved.
V. CORRECTIVE ACTIONS tv t
'TVA personnel and representatives from the recirculation pump manufacturer disassembled the pump seal and inspected the mechanical seal assembly to determine cause of the leakage.
B. tv At t TVA revised Operation Instruction 2-0I-68, "Reactor Recirculation System" to require seal purge flow to be established, prior to restarting the recircul'ation pump, to supply water to the seal cavity before opening the recirculation pump isolation valves following maintenance activities.
Specifically, this revision requires that CRD purge flow be turned on before the suction or discharge valves are opened after any maintenance that requires draining the pump cavity. Maintenance Instruction MCI-068-PMP001, "Maintenance of Reactor Recirculation Pumps," was revised to require seal flow to be on following seal maintenance activities before the suction or discharge valves are opened. These procedure requirements will prevent the loose particles from collecting in the pump seal spring assembly.
NRC Form 366(6-89)
0 NRC Form 366A U.. NUCLEAR REGULATORY COHHISSION Approved OHB No. 3150-0104 (6-09) Expires 4/30/92 LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAHE (1) iDOCKET NUHBER (2)
I I, I I SEQUENTIAL I REVIS ION I I I I I Browns Ferry Uni t 2 I Y I I I I TEXT (If more space is required, use additional NRC Form 366A's) (17)
VI. ADDITIONAL INFORMATION 2A seal spring holder assembly.
B. v None.
VII. COMMIXNEHTS None.
Energy Industry Identification System (EIIS) system and component codes are identified in the text with brackets (e.g., [XX]).
NRC Form 366(6-09)
r 4