LER 95-004-00:on 950330,reactor Scram Resulted from Personnel Error During Surveillance Testing Caused Actuation of ESF Sys.Operations Personnel Brought Plant to Shutdown ConditionML18038B259 |
Person / Time |
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Site: |
Browns Ferry |
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Issue date: |
04/28/1995 |
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From: |
Jay Wallace TENNESSEE VALLEY AUTHORITY |
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To: |
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Shared Package |
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ML18038B258 |
List: |
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References |
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LER-95-004, LER-95-4, NUDOCS 9505020309 |
Download: ML18038B259 (14) |
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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
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NRC FORN 366 (5-92)U.S.JRJCLEAR REGULATORY C(NNIISSION APPROVED BY IWB NO.3150-0104 EXP I RES 5/31/95 LZCENSEE EVENT REPORT (LER)(See reverse for required nunber of digits/characters for each block)ESTIHATED BURDEN PER RESPONSE TO COHPLY lJITH THIS INFORHATION COLLECTION REQUEST: 50.0 HRS.FORNARD COHHENTS REGARDING BURDEN ESTIHATE TO THE INFORHATION AND RECORDS HANAGEHENT BRANCH (HNBB 7714), U.S.NUCLEAR REGULATORY COHHISSION, llASHIHGTON, DC 20555-0001 AND TO THE PAPERIJORK REDUCTION PROJECT (3110-0104), OFFICE OF NANAGENENT AND BUDGET llASHINGTON DC 20503.FACILITY NAIL,(1)Browns Ferr Nuclear Plant BFN Unit 2 DOCKET NINBER (2)05000260 PAGE (3)1 OF 7 TITLE (4)Reactor scram resulting from personnel error during surveillance testing caused the actuation of the ESF system.NORTH DAY 03 30 YEAR 95 EVENT DATE 5 LER NNBER 6 SEQUENTIAL NUHBER 95 004 REVISIOH NUHBER 00 REPORT DATE 7 HONTH DAY YEAR 04 28 95 FACILITY NAHE NA DOCKET NUHBER FACILITY NAHE NA DOCKET NUHBER OTHER FACILITIES INVOLVED 8 OPERATING NX)E (9)N THIS REPORT IS SUBHITTED PURSUANT 20.402(b)TO TNE REQJIREHENTS OF 10 CFR: Check one or more 11 50.73(a)(2)(iv) 73.71(b)20.405(c)PQKR LEVEL (10)100 20.405(a)(1)(i) 20.405(a)(1)(ii) 20.405(a)(1)(iii) 20.405(a)(1)(iv) 20.405(a)(1)(v) 50.36(c)(1) 50.36(c)(2) 50.73(a)(2)(i)(B) 50.73(a)(2)(ii) 50.73(a)(2)(iii)
LICENSEE CONTACT FOR THIS LER 12 50.73(a)(2)(v) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50'3(a)(2)(x)
, 73.71(c)OTHER (Specify in Abstract below and in Text, NRC Form 366A NAHE James E.Wallace, Compliance Licensing Engineer TELEPHONE NUHBER (Include Area Code)(205)729-7874 GNPLETE ONE LINE'FOR EACH C(NPONENT FAILURE DESCRIBED IN THIS REP(NIT 13 CAUSE SYSTEH COHPONENT HANUFACTURER REPORTABLE TO NPRDS CAUSE SYSTEH COHPONENT HANUFACTURER REPORTABLE TO NPRDS SUPPLEHENTAL REPORT EXPECTED 14 YES (If yes, complete EXPECTED SUBHISSION DATE).EXPECTED SUBHI SS ION DATE (15)HONTH DAY YEAR ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)(16)On March 30, 1995, at 1800 hours0.0208 days <br />0.5 hours <br />0.00298 weeks <br />6.849e-4 months <br />, the Unit 2 reactor scrammed during the performance of the Core and Containment Systems Analog Trip Unit Functional Test.During this test, alternate rod insertion solenoid valves opened (i.e., energized) and vented control air from the scram pilot air header, causing a low scram pilot air header pressure condition (less than 53 psig.), which initiated a reactor scram.The scram then resulted in the automatic actuation of the engineered safety feature (ESF)system due to a sensed low reactor water level condition.
This event is, therefore, reportable in accordance with 10 CFR 50.73 (a)(2)(iv) as a condition which resulted in an automatic actuation of the ESF system.The root cause of the event was personnel error in that an Instrumentation and Controls technician prematurely repositioned the Anticipated Transient Without Scram mode switch from the'TEST'o the'NORMAL'osition with a test signal present.Corrective actions involve appropriate personnel corrective actions for the individual in this event.9505020309 950428 PDR ADOCK 050002b0 S PDR NRC FORH (-)
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NRC FORH 366A (5-92)LICENSEE EVENT REPORT TEXT CONTINUATION FACILITY HAHE (1)DOCKET HISSER (2)U.S.NJCLEAR REGULATORY COfBIISSIOH APPROVED BY (Ã8 HO.3150-0104 EXPIRES 5/31/95 ESTINATED BURDEN PER RESPONSE TO COHPLY WITH THIS INFORNATIOH COLLECTIOH REQUEST: 50.0 HRS.FORWARD COHHENTS REGARDING BURDEN EST IHATE TO THE'IHFORHAT ION AND RECORDS NANAGEHENT BRANCH (MNBB 7714), U.S.NUCLEAR'REGULATORY COHHISSIOH
~WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF HAHAGEHEHT AND BUDGET, WASHINGTON DC 20503 LER NWER (6)PAGE (3)TEAR SEQUENTIAL HUNGER REVI S I OH NUHBER Browns Ferry Unit 2 05000260 95'04 00 2 of 7 TEXT If more s ce is r fred use additional co les of NRC Form 366A (17)I~PLANT CONDITIONS II't the time this event occurred, Unit 2 was operating at approximately 100 percent power.Units 1 and 3 were shutdown and defueled.DESCRIPTION OF EVENT A.Event At 1800 hours0.0208 days <br />0.5 hours <br />0.00298 weeks <br />6.849e-4 months <br /> Central standard Time (CST)on March 30, 1995, Unit 2 experienced a reactor scram while the unit was at full power.Instrumentation and Controls (ZGC)technicians
[utility, non-licensed]
were performing Surveillance Instruction (SI)2-SZ-4.2.B-ATU(C),"Core and Containment Systems Analog Trip Unit Functional Test." This SI tests certain logic circuits that generate the Anticipated Transient Without Scram (ATWS)[JC]/Alternate Rod Insertion (ARI)[JD]signal for a reactor high pressure condition.
During performance of the SI, an IEC technician stationed at the analog trip unit (ATU)cabinet in Auxiliary Instrument Room,No.2 increased the stable current amplitude which locked in the relay in the ARI initiation circuitry (Figure 1).Zn step 7.11.22 of the SI, the ZRC technician was in the process of decreasing the stable current amplitude when a second IEC technician at the ATWS panel in Electric Board.Room 2A prematurely repositioned the ATWS mode switch[HS)from the'TEST'o the'NORMAL'osition.
The premature movement of the handswitch to'NORMAL'efore the ATWS/ARI logic was reset quickly vented the air from the scram pilot air header which caused a low scram pilot air header pressure condition (less than 53 psig.)and resulted in a reactor scram from Reactor Protection System (RPS)actuation.
When the scram pilot air header pressure decreased below 53 psig, the reactor scrammed as expected due to a sensed low reactor water level condition.
The reactor low level signal initiated the following primary containment isolation systems: group 2-shutdown cooling mode of the residual heat removal system[BO);group 3-reactor water cleanup system[CE];group 6-primary containment purge and vent[JM), Unit'2 reactor zone ventilation
[VB], refueling zone ventilation
[VA], standby gas,treatment system[BH), and control room emergency ventilation system[VI]initiationl and group 8-transverse in-core probes[ZG]withdrawal.
At 2316 hours0.0268 days <br />0.643 hours <br />0.00383 weeks <br />8.81238e-4 months <br />, the SI was re-performed in an attempt to duplicate the scram condition.
However, the scram condition could not be repeated in the field.On March 31, 1995 at 0220
NRC FORN 366A (5-92)U.S is)CLEAR REGULATORY C(NSIISSI(NI LICENSEE EVENT REPORT TEXT CONTINUATION APPROVED BY (H(B NO.3150-0104 EXPIRES'/31/95 ESTIHATED BURDEN PER RESPONSE TO CONPLY WITH THIS INFORHATIOH COLLECT ION REQUEST: 50.0 HRS.FORWARD CWENTS REGARDING BURDEN EST IHATE TO THE INFORNAT ION AND RECORDS NANAGENENT BRANCH (NNBB 7714), U.S.NUCLEAR REGULATORY CONNISSIOH, WASHINGTON, DC 20555-0001, AHD TO THE PAPERWORK REDUCTION PROJECT (3150.0104), OFFICE OF HAHAGENEHT AHD BUDGET, WASHIHGTON DC 20503 FACILITY NQK (1)Browne Ferry Unit 2 DOCKET NIN(BER (2)05000260 LER NWBER (6)YEAR SEQUENTIAL REVISION HUNGER NUNBER 00 95 004 PAGE (3)3 of 7 TEXT If more s ce is r ired use additional co ies of NRC Form 366A (17)Bo.hours, the SI was satisfactorily completed.
On April 2,'1995 at 1506 hours0.0174 days <br />0.418 hours <br />0.00249 weeks <br />5.73033e-4 months <br />, the, reactor was restarted and synchronized to the TVA system grid.This event is reportable in accordance with 10 CFR 50.73 (a)(2)(iv) as a condition that resulted in an automatic actuation of the ESF system.Ino erabla Structures Com onents or S stems that Contributed to the Events Co None.Dates and A roximate Times of Ma'or Occurrences:.
March 30, 1995 at 1630 CST 2-SI-4.2.B-ATU(C) commenced March 30,-1995 at 1800 CST Step 7.11.22 of the SI was in progress when the reactor scrammed March 30, 1995 at 2033 CST TVA provided a 10 CFR 50.72(b)(2)(ii) four-hour notification to NRC operations center that the reactor scrammed and the ESFs automatically actuated D.March 30, 1995 at 2316 CST The SI was re-performed in an attempt to duplicate the scram condition; the scram condition could not be repeated in the field March 31, 1995 at 0220 CST The SI was satisfactorily completed April 2, 1995 at 1506 CST Thereactor was restarted and synchronized to the TVA system grid Other S stems or Seconda Functions Affected: E~None.'Method of Discove This condition was di.scovered when the control room Operations personnel[licensed, utility)received alarms and indicators that the reactor tripped due to a sensed low reactor water level condition.
0 r NRC FORH 366A (5-92)U.S IRICLEAR REGULATORY C(MB(I SSION LICENSEE EVENT REPORT TEXT CONTINUATION APPROVED BY (MHI NO.3150-0104 EXPIRES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COHPLY'llITH THIS INFORHATION COLLECTION REQUEST: 50.0 HRS.FORNARD COHHENTS REGARD INC BURDEN EST IHATE TO THE INFORHAT ION AHD RECORDS HAHAGEHENT BRANCH (HNBB 7714), U.S.NUCLEAR REGULATORY COHHISSION, llASHIMGTON, DC 20555-0001, AMD TO THE PAPERHORK REDUCTION PROJECT (3150-0104), OFFICE OF HAMAGEHENT AND BUDGET@HASHINGTOM DC 20503 FACILITY NAIK (1)DOCKET NNBER (2)LER M(SIDER (6)YEAR SEQUENTIAL NUMBER REVI SION NUHBER PAGE (3)Browns Ferry Unit 2 05000260 95 004 00 4 of 7 TEXT lf more s ce is r ired use additional co ies of MRC Form 366A (17)F.0 erator Actionst Once the reactor scrammed, Operations personnel responded to the scram in accordance with appropriate procedures, and the reactor was stabilized and safely brought to a shutdown condition.
G.Safet S stem Res onsest ZIZ.All safety systems responded as designed fcir this type of event.CAUSE OF THE EVENT A.Immediate Cause: The immediate cause of the event was that the Unit 2 ATWS mode switch was prematurely repositioned to the'NORMAL'osition before the ATWS/ARI logic was reset.This switch movement quickly vented contiol air from the scram pilot air header causing a low scram pilot air header pressure condition (less than 53 psig.)and resulted in an RPS reactor scram.B.Root Causel The root cause of the event was personnel error.An IGC technician prematurely repositioned the ATWS mode switch from the'TEST'o the'NORMAL'osition.
The procedure requires that the switch remain in the'TEST'osition with the logic signal present to prevent energizing the solenoid valves which vent the scram pilot air header.ZVo ANALYSIS OF THE EVENT The ATWS/ARI system is designed as a redundant, independent and diverse reactor shutdown system.The ATWS/ARI system provides an alternate means of venting the scram pilot air header to generate a reactor scram in the event of an anticipated transient without the desired RPS response.As expected, the solenoid valves that vented the scram pilot air header remained energized until the initiation logic was reset.The ATWS instrumentation also affects parameters that initiate or.control primary containment isolation and initiation of plant ventilation systems.In this event, control air was vented from the scram pilot air header resulting in the initiation of the ATWS/ARI, which caused the control rods to insert to safely shut down the reactor.All plant equipment responded as designed.Therefore, this event did not affect the health and safety of plant personnel and the public.
t,)
NRC FORII 366A (5-92)U.S.IRICLEAR REGULATORY CQNIISSI ON LICENSEE EVENT REPORT TEXT'CONTINUATION APPROVED BY (NB NO.3150-0104 EXPIRES.5/31/95 ESTIHATED BURDEN PER RESPOHSE TO COHPLY llITH THIS IHFORHATIOH COLLECTION REQUEST: 50.0 HRS~FORNARD COHNENTS REGARD IHG BURDEN EST IHATE TO THE IHFORNATIOH AND RECORDS HANAGEHENT BRANCH (NHBB 7714), U.S.NUCLEAR REGULATORY COHNISSION, iJASHIHGTON, DC 20555-0001, AND TO THE PAPERHORK REDUCTION PROJECT (3150-0104), OFFICE OF'ANAGEHEHT AHD BUDGET,'MASHINGTON DC 20503 FACILITY NAIL (1)DOCKET NWSER (2)YEAR LER HISSER (6)SEQUENTIAL NUNBER REVISI OH HUHBER PAGE (3),Browns Ferry Unit 2 05000260 95 004 00 5 of 7 TEXT tf more s ce is r ired use additional co ies of NRC Form 366A'(17)V CORRECTIVE ACTIONS A.Immediate Corrective Actionsl Operations personnel responded to the reactor scram and safely.brought the plant to a shutdown condition.
The SI was stopped.The ATWS mode switch was investigated to ensure that the correct contacts were opened.The switch was replaced and was bench-tested/examined for any evidence of contact wiper failure/sticking.
However, the switch internals did not reveal any adverse indications (e.g., contacts burned, cam or switch mechanism problems).
The SI.was reviewed to determine if any errors existed and then re-preformed in an attempt to replicate the scram condition.
However, the scram condition could not be repeated.The SI was then satisfactorily completed.
An incident investigation was i'nitiated to determine the root cause of the event and appropriate corrective actions.B.Corrective Actions to Prevent Recurrencel Corrective actions involve appropriate personnel corrective actions for the individual in this event.VI~ADDITIONAL INFORMATION A.Failed Com onentsI B.None.Previous Licensee Event Re orts LERs on Similar Events: Although there have been previous LERs for personnel error where a control was inappropriately manipulated or operated out-of-sequence, none of the previous corrective actions would not have precluded this event.LER 260/93004 addressed a high reactor pressure condition that resulted in an ATWS signal and initiated an ARI signal.The cause of the LER (260/93004) was inattention to detail in that an operator[utility, licensed)did not adequately evaluate the overall effects of ongoing SIs.Thi.s oversight subsequently caused a reactor scram.However, the corrective actions for LER (260/93004) would not have precluded this event (LER 260/95004) because the root cause of the previous LER was schedular in nature in that the unit Operator presumed that IEC personnel would notify him prior to each instrument being removed from service.In this LER (260/95004)
Operations personnel were informed at appropriate times as required in the SI so that no schedular conflicts existed.
II r 1 II NRC FORII 366A (5-92)U.S IN)CLEAR REGUIATQtY CQBI I SSION LICENSEE EVENT REPORT TEXT CONTINUATION APPROVED BY QIB NO.3150-0104 EXP I RES 5/31/95 ESTIHATED BURDEN PER RESPQISE TO COHPLY IJITH THIS INFORHATION COLLECTION REOUEST: 50.0 HRS~FORMARD COHHENTS REGARDING , BURDEH'EST IHATE.TO THE INFORHAT I OH AND RECORDS HANAGEHENT BRANCH (HNBB 7714), U.ST NUCLEAR REGULATORY COHHISSIOH, NASHIHGTOH, DC 20555-0001, AND TO THE PAPERIQRK REDUCTION PROJECT (3150-0104), OFFICE OF HAHAGEHENT AND BUDGET, llASHINGTON DC 20503 FACILITY NAIL (1)DOCKET NINIBER" (2)LER.NWBER (6l YEAR SEQUENTIAL NUHBER REVI S I OH NUHBER PAGE (3l Browne Ferry Unit 2 05000260 95 004 00 6 of'7 TEXT If more s ce is r ired Use additionst co ies of NRC Form 366A (17)VIE Commitments None..Energy Industry Identification System (EIIS)system and component, codes are identified in the text with brackets (e.g.,[XX)).
P MRC FORM 366A (5-92)U.S NUCLEAR REGULATORY C(MBIISSIOH LICENSEE EVENT REPORT TEXT CONTZNUATZON
~APPROVED BY (BIB NO.3150-0104 EXPIRES 5/31/95 ESTIHATED BURDEH PER RESPONSE TO COHPLY llITH THIS INFORMATION COLLECT IOM REQUESTs 50+0 HRSo FORl!ARD COHHENTS REGARDING BURDEH ESTIHATE TO THE INFORHAT ION AND RECORDS MANAGEMENT BRANCH (HNBB 7714), U.S.NUCLEAR REGULATORY COHHI SS ION g MASHIMGTON, DC 20555-0001, AND TO THE PAPERMORK REDUCTION PROJECT (3150-0104)
~OFFICE OF MANAGEMENT AND BUDGET, IIASHINGTOM DC 20503 FACILITY NQK (1)DOCKET NMSER (2)LER MIMKR (6)YEAR SEQUENTIAL REVISION NUMBER NUMBER PAGE (3)Browne Ferry Unit 2 05000260 95 004 00 7 of 7 TEXT If more s ce is r ired use edditiossai co es of NRC orm 366A (17)ATVS HS.TEST ZBO V.D.C.QIODE RELAY ATVS HS.NORM SOLENOID ARI INITIATION SIGNAL 4l'l