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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20046B1481993-07-30030 July 1993 LER 93-012-00:on 930702,reactor Core Isolation Cooling Sys Declared Inoperable Due to Associated Bus Voltage Dropping Below TS Limits.Sent Operator to Cycle Timer Which Caused Affected Contact to reclose.W/930730 Ltr ML20045D9331993-07-0202 July 1993 LER 93-004-00:on 930604,unexpected CRD Low Charging Water Header Scram Received Followed by Charging Water Header A2/B2 Alarm.Caused by Crud or Foreign Matl Passing Through Suction Filter.Filters Cleaned & reused.W/930702 ML20045D7501993-06-23023 June 1993 LER 93-003-00:on 930524,Div 1 ECCS Initiation Signal Received & LPCS Pump,Lpci Pump 2A & EDG Unit 0 Automatically Started.Caused by Personnel Error.Pumps Secured & Event Documented in Personnel file.W/930623 Ltr ML20044E4161993-05-28028 May 1993 LER 92-009-01:on 920923,spurious Auto Start of CR Ventilation Emergency make-up Train Occurred Due to High Radiation Spike.Radiation Monitor Circuit modified.W/930528 Ltr ML20044E4191993-05-21021 May 1993 LER 93-011-00:on 930423,manual Scram Initiated.Caused by Disconnected Linkage on Valve Positioner on Heater Drain Valve Due to Loose Jam Nut.Tailgate Session Will Be Held W/ Instrument Maint Dept Re Jam nuts.W/930521 Ltr ML20044D5161993-05-15015 May 1993 LER 92-007-01:on 920613,high Radiation Spike Received from CR Ventilation Process Radiation Monitor,Initiating Emergency Makeup Train B.Caused by Normal Variations in Radiation Readings.Spike modified.W/930515 Ltr ML20044D5571993-05-14014 May 1993 LER 93-010-00:on 930414,DG Cooling Water Pump Automatically Tripped on Magnetic Overload.Caused by Inexperienced Trainee in Operation of Control Lever.Lesson Plans & Training Programs for Operators to Be reviewed.W/930514 Ltr ML20044C9801993-05-0707 May 1993 LER 91-010-01:on 910719 & 0805,CR a Ventilation Emergency Makeup Fan auto-started on Spurious Trip of CR Air Intake Process Radiation Monitor.Caused by Normal Variations in Background Radiation.Supply Board replaced.W/930507 Ltr ML20044B6161993-02-25025 February 1993 LER 93-002-00:on 930126,Unit 1 Manual Scram Due to a SRV Being Stuck Open Due to Duct Tape Being Over Actuators Air Valve Manifold Exhaust Port.Maint Procedures That Involve Cleanliness reviewed.W/930225 Ltr ML20024G9771991-05-10010 May 1991 LER 91-005-00:on 910410,determined That Tech Spec Required Surveillance of Suppression Chamber Oxygen Sampling Missed. Caused by Inadequate Review of Tech Spec Change.Drywell & Suppression Chamber Checked for oxygen.W/910510 Ltr ML20044A3851990-06-25025 June 1990 LER 90-008-00:on 900525,Tech Spec Hourly Fire Watch Missed Due to Miscommunications Between Security Personnel & Radiation Protection Personnel.Fire Watch re-established & Memo issued.W/900625 Ltr ML20043F1721990-06-0505 June 1990 LER 90-009-00:on 900510,RWCU Outboard Suction Isolation Valve 2G33-F004 Auto Closed Which Tripped RWCU Pump B. Caused by Procedure Deficiency.Procedure LTS-500-209 Will Be revised.W/900605 Ltr ML20043F1281990-06-0101 June 1990 LER 90-009-00:on 900511,apparent Ruptured Diaphragm Found on Pressure Differential Switch in RCIC Steam Line.Caused by Torn Diaphragm Inside Switch.Replacement Switch Installed, Calibr & Functionally Tested satisfactorily.W/900608 Ltr ML20043B5681990-05-23023 May 1990 LER 89-027-01:on 891113,primary Containment Isolation Sys Group 1 Isolation Occurred During Surveillance Testing. Caused by Burnt Out Window Light Bulbs on Alarm Window. Light Bulbs Replaced & Jumpers installed.W/900523 Ltr ML20043A7721990-05-18018 May 1990 LER 90-007-00:on 900421,reactor Protection Sys Bus a Transfer & Reactor Recirculation Hydraulic Power Unit a Inboard Isolation Valves Closed,Causing Partial Group II isolation.Out-of-svc Procedure revised.W/900518 Ltr ML20043D0591990-05-18018 May 1990 LER 90-008-00:on 900502,ESF Actuation of Control Room B Emergency Ctk Ventilation Makeup Fan Occurred.Caused by Procedure deficiency.LTS-800-205 & Similar Procedures Will Be revised.W/900601 Ltr ML20042H0211990-05-10010 May 1990 LER 90-006-00:on 900412,loop a Primary Containment Chilled Water Sys Inboard Isolation Valves & Reactor Bldg Closed Cooling Water Sys Inboard Isolation Valve Went Closed.Caused by Inadequate Procedure.Procedures revised.W/900510 Ltr ML20042F9001990-05-0404 May 1990 LER 90-005-00:on 900411,experienced Loss of Dc Power to Portion of Div I Primary Containment Isolation Sys Logic Which Resulted in Isolation Signal & Actuation.Caused by Failure to Update Drawings & procedures.W/900504 Ltr ML20042F1941990-04-30030 April 1990 LER 89-025-01:on 891101,sys Auxiliary Transformer Feed to Bus 142Y Tripped Open When Door Containing Undervoltage Relays Closed.Caused by Misalignment of Door.Door Repaired. W/900430 Ltr ML20012D5341990-03-16016 March 1990 LER 90-003-01:on 900201,RCIC Isolation Signal Occurred During Warmup.Caused by Spurious High Steam Flow Signal.Rcic Sys Piping Integrity Verified & Isolation Logic Reset.W/ 900316 Ltr ML20012D5371990-03-16016 March 1990 LER 90-002-01:on 900129,oil in Diesel Generator Governor 1A Found to Be Low & Could Not Be Seen in Sight Glass.Caused by Slow Leak from Compensation Needle Valve Plug.Proper Amount of Oil Added & Operability Test performed.W/900316 Ltr ML20012C4931990-03-15015 March 1990 LER 90-004-00:on 900213,control Room B HVAC Intake Radiation Monitor Lost Power Causing auto-start of Emergency make-up Train B.Caused by Blown Fuses.Fuses Replaced.Logic Revs for Radiation Monitors Will Be installed.W/900315 Ltr ML20012B6501990-03-0909 March 1990 LER 90-002-00:on 900209,Operating Surveillance LOS-TG-W1 Determined to Have Exceeded Required Testing Interval,Per Tech Spec 3/4.7.10.Caused by Personnel Error.Personnel Counseled & Ref Procedures Will Be revised.W/900309 Ltr ML20012B5521990-03-0808 March 1990 LER 90-001-00:on 900206,full Reactor Scram Occurred During Instrument Surveillance Testing.Caused by Actuation of APRM E Trip Circuitry.Shutdown Margin Revised & Caution Card Placed on Control Room Bench board.W/900308 Ltr ML20011F8251990-03-0202 March 1990 LER 90-003-00:on 900201,RCIC Received Div 2 Isolation on RCIC High Steam Line Flow.Caused by Spurious High Steam Flow Signal Generated When Steam/Water Mixture Admitted to RCIC Steam Line.Isolation Logic reset.W/900302 Ltr ML20011F5551990-02-28028 February 1990 LER 90-002-00:on 900129,after Filling Diesel Generator 1A Governor W/Oil,Generator Started & Declared Inoperable. Caused by Slow Leak Coming from Compensation Needle Valve Plug.Oil Added & Plug Washer replaced.W/900228 Ltr ML20006F5951990-02-21021 February 1990 LER 90-001-00:on 900122,RWCU Sys Received Div 1 Leakage Detection Ambient Temp High Isolation Signal,Causing Trips of RWCU Pumps a & C.Caused by Broken Thermocouple Input Lead.Lead Wire Reconnected & Isolation reset.W/900221 Ltr ML20011F4921990-02-16016 February 1990 LER 89-013-01:on 890907,Group I Isolation Received During Performance of Instrument Surveillance LIS-MS-401.Caused by Depressurization of Main Steam Line Low Pressure Switch. Surveillance Revised to Split Into Two parts.W/900216 Ltr ML20006E4501990-02-15015 February 1990 LER 89-010-01:on 890715 & 17,voltage Oscillations Noted on Div II Battery Charger,Resulting in Inoperability of HPCS Sys.Caused by Failure of Charger in High Voltage Shutdown Relay.Charger Energized & Relay replaced.W/900215 Ltr ML20006E4451990-02-14014 February 1990 LER 89-009-01:on 890619,diaphragm Leak Discovered in RCIC Steam Line High Flow Isolation Switch.Caused by 1 & 1/2-inch Tear in Diaphragm.Pressure Differential Switch Replaced & Calibr.Reported Per NRC Bulletin 86-002.W/900214 Ltr ML20006E3981990-02-14014 February 1990 LER 89-008-01:on 890228,reactor Vessel Low Water Level 2 Switch Found W/Setpoint in Excess of Reject Limit.Caused by Setpoint Drift.Channel Placed in Tripped Condition & All Static-O-Ring Pressure Switches to Be replaced.W/900214 Ltr ML20006E3951990-02-14014 February 1990 LER 89-010-01:on 890303,automatic Depressurization Sys Permissive Switch Found W/Setpoint in Excess of Reject Limit.Caused by Setpoint Drift.All Static-O-Ring Reactor Vessel Level Switches Will Be replaced.W/900214 Ltr ML19354D8361990-01-15015 January 1990 LER 89-018-00:on 891216,plant 250-volt Battery & RCIC Sys Declared Inoperable Due to Low Battery Electrolyte Temps. Caused by Failure of Div I Switchgear Heat Removal Sys Damper Actuators.Air Intake Dampers closed.W/900115 Ltr ML20042D3921990-01-0404 January 1990 LER 89-011-01:on 890826,spurious Reactor Protection Sys Actuation Occurred.Definite Cause of Trip Not Determined. Brief Disturbance in Reactor Protection Sys Allowed Some Contactors to Trip.Procedure revised.W/900104 Ltr ML20005E2741989-12-22022 December 1989 LER 89-028-00:on 891204,RHR Shutdown Cooling Suction Header Outboard Isolation Valve Automatically Isolated.Caused by Miscommunication Between Technician & Station Operator.Task Force Developed to Review event.W/891222 Ltr ML19351A6301989-12-15015 December 1989 LER 89-006-01:on 890214,reactor Vessel Low Water Level 3 Switch Setpoint Found Out of Tolerance.Caused by Setpoint Drift.Level Switch to Be Replaced by Analog Trip Sys During First Quarter 1990.W/891215 Ltr ML20011D1341989-12-14014 December 1989 LER 89-017-00:on 891117,flow Switch FS-2E22-N006 Found W/ Setpoint Out of Tolerance Above Reject Limit.Caused by Setpoint Drift.Work Request Written to Replace Flow Switch. W/891214 Ltr ML19351A6751989-12-12012 December 1989 LER 89-027-00:on 891113,primary Containment Isolation Sys Group I Isolation Occurred While Performing Instrument Surveillance.Caused by Loss of Power to Leak Detection Sys Logic.Isolation reset.W/891213 Ltr ML19332F0081989-12-0808 December 1989 LER 89-016-00:on 891109,RWCU Isolation Occurred While Instrument Surveillance on Ventilation Differential Temp Isolation Functional Test in Progress.Caused by Faulty Thermocouple.Thermocouple repaired.W/891208 Ltr ML20005D6621989-12-0606 December 1989 LER 89-026-00:on 891106,inadvertent Primary Containment Isolation Actuation Occurred While Clearing out-of-svc. Caused by Inadequate Logic Setup During Mod Installation. Trip Status & Output Switches repositioned.W/891206 Ltr ML19332F2431989-12-0101 December 1989 LER 89-025-00:on 891101,sys Auxiliary Transformer Feed to Bus 142Y Tripped Open When Equipment Operator Closed Door Containing Relays.Caused by Misalignment of Door.Isolations Reset,Bus Energized & Circuit Logic tested.W/891201 Ltr ML19332E6581989-11-29029 November 1989 LER 89-015-00:on 891030,shift Control Room Engineer Noted That Quarterly Standby Liquid Control Operating Surveillance LOS-SC-Q1 Was Past Critical Date.Caused by Clerical Data Entry Error.Missed Surveillance performed.W/891129 Ltr ML19332D5181989-11-22022 November 1989 LER 89-018-01:on 890515,RCIC Received Div I & Div II Isolation on RCIC High Steam Line Flow.Caused by Spurious High Steam Flow Signal When Steam Added to RCIC Steam Line. Special Test Initiated.Isolation Logic reset.W/891122 Ltr ML19327C2601989-11-17017 November 1989 LER 89-014-00:on 891020,primary Containment Isolation Sys Group 4 Isolation Occurred Causing Isolation Dampers to Close.Caused by Opening of Div 2 125-volt Dc Breaker.Power Supply replaced.W/891117 Ltr ML19325F3411989-11-13013 November 1989 LER 89-024-00:on 891013 & 30,unsealed Openings in Main Control Room Floor & Main Control Room West Wall Discovered. Caused by Wide Gap Between Structural Beam & Cable Tray. Openings Sealed & Fire Watch established.W/891113 Ltr ML19324C1751989-11-0808 November 1989 LER 89-012-01:on 890309,diaphragm Leak Found in Pressure Differential Switch 1E31-N013BB.Caused by Tear Found in Diaphragm.Replacement Switch Installed,Calibr & Functionally Tested satisfactorily.W/891108 Ltr ML20024E9121983-08-26026 August 1983 LER 83-093/03L-0:on 830801,discovered full-in Indication on Core Display for Control Rod 34-47 Inoperable.Caused by Failed Switching Transistor on Data Memory Board 19.Data Memory Board replaced.W/830826 Ltr ML20024B8381983-07-0505 July 1983 LER 83-060/03L-0:on 830606,following Turbine Trip & Scram Due to High Vibration on Main Turbine,Reactor Recirculation Breaker 4B Closed.Cause Undetermined.Auxiliary Contacts cleaned.W/830705 Ltr ML20024B0721983-06-16016 June 1983 Updated LER 83-012/03X-1:on 830210,w/reactor in Cold Shutdown,Setpoints for Switches 1E31-N612A/B Found Above Tech Spec Limits.Cause Unknown.Switches calibr.W/830616 Ltr ML20024A6961983-06-14014 June 1983 LER 83-051/03L-0:on 830516,reactor Protection Sys Trip Channel H2 Limit Switch Failed to Operate Properly.Cause Unknown.Limit Switch readjusted.W/830614 Ltr 1993-07-30
[Table view] Category:RO)
MONTHYEARML20046B1481993-07-30030 July 1993 LER 93-012-00:on 930702,reactor Core Isolation Cooling Sys Declared Inoperable Due to Associated Bus Voltage Dropping Below TS Limits.Sent Operator to Cycle Timer Which Caused Affected Contact to reclose.W/930730 Ltr ML20045D9331993-07-0202 July 1993 LER 93-004-00:on 930604,unexpected CRD Low Charging Water Header Scram Received Followed by Charging Water Header A2/B2 Alarm.Caused by Crud or Foreign Matl Passing Through Suction Filter.Filters Cleaned & reused.W/930702 ML20045D7501993-06-23023 June 1993 LER 93-003-00:on 930524,Div 1 ECCS Initiation Signal Received & LPCS Pump,Lpci Pump 2A & EDG Unit 0 Automatically Started.Caused by Personnel Error.Pumps Secured & Event Documented in Personnel file.W/930623 Ltr ML20044E4161993-05-28028 May 1993 LER 92-009-01:on 920923,spurious Auto Start of CR Ventilation Emergency make-up Train Occurred Due to High Radiation Spike.Radiation Monitor Circuit modified.W/930528 Ltr ML20044E4191993-05-21021 May 1993 LER 93-011-00:on 930423,manual Scram Initiated.Caused by Disconnected Linkage on Valve Positioner on Heater Drain Valve Due to Loose Jam Nut.Tailgate Session Will Be Held W/ Instrument Maint Dept Re Jam nuts.W/930521 Ltr ML20044D5161993-05-15015 May 1993 LER 92-007-01:on 920613,high Radiation Spike Received from CR Ventilation Process Radiation Monitor,Initiating Emergency Makeup Train B.Caused by Normal Variations in Radiation Readings.Spike modified.W/930515 Ltr ML20044D5571993-05-14014 May 1993 LER 93-010-00:on 930414,DG Cooling Water Pump Automatically Tripped on Magnetic Overload.Caused by Inexperienced Trainee in Operation of Control Lever.Lesson Plans & Training Programs for Operators to Be reviewed.W/930514 Ltr ML20044C9801993-05-0707 May 1993 LER 91-010-01:on 910719 & 0805,CR a Ventilation Emergency Makeup Fan auto-started on Spurious Trip of CR Air Intake Process Radiation Monitor.Caused by Normal Variations in Background Radiation.Supply Board replaced.W/930507 Ltr ML20044B6161993-02-25025 February 1993 LER 93-002-00:on 930126,Unit 1 Manual Scram Due to a SRV Being Stuck Open Due to Duct Tape Being Over Actuators Air Valve Manifold Exhaust Port.Maint Procedures That Involve Cleanliness reviewed.W/930225 Ltr ML20024G9771991-05-10010 May 1991 LER 91-005-00:on 910410,determined That Tech Spec Required Surveillance of Suppression Chamber Oxygen Sampling Missed. Caused by Inadequate Review of Tech Spec Change.Drywell & Suppression Chamber Checked for oxygen.W/910510 Ltr ML20044A3851990-06-25025 June 1990 LER 90-008-00:on 900525,Tech Spec Hourly Fire Watch Missed Due to Miscommunications Between Security Personnel & Radiation Protection Personnel.Fire Watch re-established & Memo issued.W/900625 Ltr ML20043F1721990-06-0505 June 1990 LER 90-009-00:on 900510,RWCU Outboard Suction Isolation Valve 2G33-F004 Auto Closed Which Tripped RWCU Pump B. Caused by Procedure Deficiency.Procedure LTS-500-209 Will Be revised.W/900605 Ltr ML20043F1281990-06-0101 June 1990 LER 90-009-00:on 900511,apparent Ruptured Diaphragm Found on Pressure Differential Switch in RCIC Steam Line.Caused by Torn Diaphragm Inside Switch.Replacement Switch Installed, Calibr & Functionally Tested satisfactorily.W/900608 Ltr ML20043B5681990-05-23023 May 1990 LER 89-027-01:on 891113,primary Containment Isolation Sys Group 1 Isolation Occurred During Surveillance Testing. Caused by Burnt Out Window Light Bulbs on Alarm Window. Light Bulbs Replaced & Jumpers installed.W/900523 Ltr ML20043A7721990-05-18018 May 1990 LER 90-007-00:on 900421,reactor Protection Sys Bus a Transfer & Reactor Recirculation Hydraulic Power Unit a Inboard Isolation Valves Closed,Causing Partial Group II isolation.Out-of-svc Procedure revised.W/900518 Ltr ML20043D0591990-05-18018 May 1990 LER 90-008-00:on 900502,ESF Actuation of Control Room B Emergency Ctk Ventilation Makeup Fan Occurred.Caused by Procedure deficiency.LTS-800-205 & Similar Procedures Will Be revised.W/900601 Ltr ML20042H0211990-05-10010 May 1990 LER 90-006-00:on 900412,loop a Primary Containment Chilled Water Sys Inboard Isolation Valves & Reactor Bldg Closed Cooling Water Sys Inboard Isolation Valve Went Closed.Caused by Inadequate Procedure.Procedures revised.W/900510 Ltr ML20042F9001990-05-0404 May 1990 LER 90-005-00:on 900411,experienced Loss of Dc Power to Portion of Div I Primary Containment Isolation Sys Logic Which Resulted in Isolation Signal & Actuation.Caused by Failure to Update Drawings & procedures.W/900504 Ltr ML20042F1941990-04-30030 April 1990 LER 89-025-01:on 891101,sys Auxiliary Transformer Feed to Bus 142Y Tripped Open When Door Containing Undervoltage Relays Closed.Caused by Misalignment of Door.Door Repaired. W/900430 Ltr ML20012D5341990-03-16016 March 1990 LER 90-003-01:on 900201,RCIC Isolation Signal Occurred During Warmup.Caused by Spurious High Steam Flow Signal.Rcic Sys Piping Integrity Verified & Isolation Logic Reset.W/ 900316 Ltr ML20012D5371990-03-16016 March 1990 LER 90-002-01:on 900129,oil in Diesel Generator Governor 1A Found to Be Low & Could Not Be Seen in Sight Glass.Caused by Slow Leak from Compensation Needle Valve Plug.Proper Amount of Oil Added & Operability Test performed.W/900316 Ltr ML20012C4931990-03-15015 March 1990 LER 90-004-00:on 900213,control Room B HVAC Intake Radiation Monitor Lost Power Causing auto-start of Emergency make-up Train B.Caused by Blown Fuses.Fuses Replaced.Logic Revs for Radiation Monitors Will Be installed.W/900315 Ltr ML20012B6501990-03-0909 March 1990 LER 90-002-00:on 900209,Operating Surveillance LOS-TG-W1 Determined to Have Exceeded Required Testing Interval,Per Tech Spec 3/4.7.10.Caused by Personnel Error.Personnel Counseled & Ref Procedures Will Be revised.W/900309 Ltr ML20012B5521990-03-0808 March 1990 LER 90-001-00:on 900206,full Reactor Scram Occurred During Instrument Surveillance Testing.Caused by Actuation of APRM E Trip Circuitry.Shutdown Margin Revised & Caution Card Placed on Control Room Bench board.W/900308 Ltr ML20011F8251990-03-0202 March 1990 LER 90-003-00:on 900201,RCIC Received Div 2 Isolation on RCIC High Steam Line Flow.Caused by Spurious High Steam Flow Signal Generated When Steam/Water Mixture Admitted to RCIC Steam Line.Isolation Logic reset.W/900302 Ltr ML20011F5551990-02-28028 February 1990 LER 90-002-00:on 900129,after Filling Diesel Generator 1A Governor W/Oil,Generator Started & Declared Inoperable. Caused by Slow Leak Coming from Compensation Needle Valve Plug.Oil Added & Plug Washer replaced.W/900228 Ltr ML20006F5951990-02-21021 February 1990 LER 90-001-00:on 900122,RWCU Sys Received Div 1 Leakage Detection Ambient Temp High Isolation Signal,Causing Trips of RWCU Pumps a & C.Caused by Broken Thermocouple Input Lead.Lead Wire Reconnected & Isolation reset.W/900221 Ltr ML20011F4921990-02-16016 February 1990 LER 89-013-01:on 890907,Group I Isolation Received During Performance of Instrument Surveillance LIS-MS-401.Caused by Depressurization of Main Steam Line Low Pressure Switch. Surveillance Revised to Split Into Two parts.W/900216 Ltr ML20006E4501990-02-15015 February 1990 LER 89-010-01:on 890715 & 17,voltage Oscillations Noted on Div II Battery Charger,Resulting in Inoperability of HPCS Sys.Caused by Failure of Charger in High Voltage Shutdown Relay.Charger Energized & Relay replaced.W/900215 Ltr ML20006E4451990-02-14014 February 1990 LER 89-009-01:on 890619,diaphragm Leak Discovered in RCIC Steam Line High Flow Isolation Switch.Caused by 1 & 1/2-inch Tear in Diaphragm.Pressure Differential Switch Replaced & Calibr.Reported Per NRC Bulletin 86-002.W/900214 Ltr ML20006E3981990-02-14014 February 1990 LER 89-008-01:on 890228,reactor Vessel Low Water Level 2 Switch Found W/Setpoint in Excess of Reject Limit.Caused by Setpoint Drift.Channel Placed in Tripped Condition & All Static-O-Ring Pressure Switches to Be replaced.W/900214 Ltr ML20006E3951990-02-14014 February 1990 LER 89-010-01:on 890303,automatic Depressurization Sys Permissive Switch Found W/Setpoint in Excess of Reject Limit.Caused by Setpoint Drift.All Static-O-Ring Reactor Vessel Level Switches Will Be replaced.W/900214 Ltr ML19354D8361990-01-15015 January 1990 LER 89-018-00:on 891216,plant 250-volt Battery & RCIC Sys Declared Inoperable Due to Low Battery Electrolyte Temps. Caused by Failure of Div I Switchgear Heat Removal Sys Damper Actuators.Air Intake Dampers closed.W/900115 Ltr ML20042D3921990-01-0404 January 1990 LER 89-011-01:on 890826,spurious Reactor Protection Sys Actuation Occurred.Definite Cause of Trip Not Determined. Brief Disturbance in Reactor Protection Sys Allowed Some Contactors to Trip.Procedure revised.W/900104 Ltr ML20005E2741989-12-22022 December 1989 LER 89-028-00:on 891204,RHR Shutdown Cooling Suction Header Outboard Isolation Valve Automatically Isolated.Caused by Miscommunication Between Technician & Station Operator.Task Force Developed to Review event.W/891222 Ltr ML19351A6301989-12-15015 December 1989 LER 89-006-01:on 890214,reactor Vessel Low Water Level 3 Switch Setpoint Found Out of Tolerance.Caused by Setpoint Drift.Level Switch to Be Replaced by Analog Trip Sys During First Quarter 1990.W/891215 Ltr ML20011D1341989-12-14014 December 1989 LER 89-017-00:on 891117,flow Switch FS-2E22-N006 Found W/ Setpoint Out of Tolerance Above Reject Limit.Caused by Setpoint Drift.Work Request Written to Replace Flow Switch. W/891214 Ltr ML19351A6751989-12-12012 December 1989 LER 89-027-00:on 891113,primary Containment Isolation Sys Group I Isolation Occurred While Performing Instrument Surveillance.Caused by Loss of Power to Leak Detection Sys Logic.Isolation reset.W/891213 Ltr ML19332F0081989-12-0808 December 1989 LER 89-016-00:on 891109,RWCU Isolation Occurred While Instrument Surveillance on Ventilation Differential Temp Isolation Functional Test in Progress.Caused by Faulty Thermocouple.Thermocouple repaired.W/891208 Ltr ML20005D6621989-12-0606 December 1989 LER 89-026-00:on 891106,inadvertent Primary Containment Isolation Actuation Occurred While Clearing out-of-svc. Caused by Inadequate Logic Setup During Mod Installation. Trip Status & Output Switches repositioned.W/891206 Ltr ML19332F2431989-12-0101 December 1989 LER 89-025-00:on 891101,sys Auxiliary Transformer Feed to Bus 142Y Tripped Open When Equipment Operator Closed Door Containing Relays.Caused by Misalignment of Door.Isolations Reset,Bus Energized & Circuit Logic tested.W/891201 Ltr ML19332E6581989-11-29029 November 1989 LER 89-015-00:on 891030,shift Control Room Engineer Noted That Quarterly Standby Liquid Control Operating Surveillance LOS-SC-Q1 Was Past Critical Date.Caused by Clerical Data Entry Error.Missed Surveillance performed.W/891129 Ltr ML19332D5181989-11-22022 November 1989 LER 89-018-01:on 890515,RCIC Received Div I & Div II Isolation on RCIC High Steam Line Flow.Caused by Spurious High Steam Flow Signal When Steam Added to RCIC Steam Line. Special Test Initiated.Isolation Logic reset.W/891122 Ltr ML19327C2601989-11-17017 November 1989 LER 89-014-00:on 891020,primary Containment Isolation Sys Group 4 Isolation Occurred Causing Isolation Dampers to Close.Caused by Opening of Div 2 125-volt Dc Breaker.Power Supply replaced.W/891117 Ltr ML19325F3411989-11-13013 November 1989 LER 89-024-00:on 891013 & 30,unsealed Openings in Main Control Room Floor & Main Control Room West Wall Discovered. Caused by Wide Gap Between Structural Beam & Cable Tray. Openings Sealed & Fire Watch established.W/891113 Ltr ML19324C1751989-11-0808 November 1989 LER 89-012-01:on 890309,diaphragm Leak Found in Pressure Differential Switch 1E31-N013BB.Caused by Tear Found in Diaphragm.Replacement Switch Installed,Calibr & Functionally Tested satisfactorily.W/891108 Ltr ML20024E9121983-08-26026 August 1983 LER 83-093/03L-0:on 830801,discovered full-in Indication on Core Display for Control Rod 34-47 Inoperable.Caused by Failed Switching Transistor on Data Memory Board 19.Data Memory Board replaced.W/830826 Ltr ML20024B8381983-07-0505 July 1983 LER 83-060/03L-0:on 830606,following Turbine Trip & Scram Due to High Vibration on Main Turbine,Reactor Recirculation Breaker 4B Closed.Cause Undetermined.Auxiliary Contacts cleaned.W/830705 Ltr ML20024B0721983-06-16016 June 1983 Updated LER 83-012/03X-1:on 830210,w/reactor in Cold Shutdown,Setpoints for Switches 1E31-N612A/B Found Above Tech Spec Limits.Cause Unknown.Switches calibr.W/830616 Ltr ML20024A6961983-06-14014 June 1983 LER 83-051/03L-0:on 830516,reactor Protection Sys Trip Channel H2 Limit Switch Failed to Operate Properly.Cause Unknown.Limit Switch readjusted.W/830614 Ltr 1993-07-30
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217C9121999-10-12012 October 1999 SER Input Authorizing Licensee Proposed Request to Modify Definition of Core Alteration in Section 1.0 of TS & Update Sections 3/4.1,3.4.3 & 3/4.9 to Reflect Proposed Definition Change ML20217F9091999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for LaSalle County Stations,Units 1 & 2.With ML20217A1691999-09-22022 September 1999 Part 21 Rept Re Engine Sys,Inc Controllers,Manufactured Between Dec 1997 & May 1999,that May Have Questionable Soldering Workmanship.Caused by Inadequate Personnel Training.Sent Rept to All Nuclear Customers ML20212C4501999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for LaSalle County Station,Units 1 & 2.With ML20210R0671999-07-31031 July 1999 Monthly Operating Repts for July 1999 for LaSalle County Station,Units 1 & 2.With ML20210C1681999-07-0909 July 1999 Seventh Refueling Outage ASME Section XI Summary Rept ML20209H1501999-06-30030 June 1999 Monthly Operating Repts for June 1999 for LaSalle County Station,Units 1 & 2.With ML20195J7871999-05-31031 May 1999 Monthly Operating Repts for May 1999 for LaSalle County Station,Units 1 & 2.With ML20209E1431999-05-31031 May 1999 Cycle 8 COLR, for May 1999 ML20195B2591999-05-19019 May 1999 Rev 66a to CE-1-A,consisting of Proposed Changes to QAP for Dnps,Qcs,Znps,Lcs,Byron & Braidwood Stations ML20206N2071999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for LaSalle County Station,Units 1 & 2.With ML20205L8421999-03-31031 March 1999 Rev 2 to EMF-96-125, LaSalle Unit 2 Cycle 8 Reload Analysis ML20205L8301999-03-31031 March 1999 Administrative Technical Requirements App B (Amend 26) LaSalle Unit 2 Cycle 8 COLR & Reload Transient Analysis Results, for Mar 1999 ML20205R2721999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for LaSalle County Station,Units 1 & 2.With ML20205L8391999-03-22022 March 1999 Rev 2 to 960103, Neutronics Licensing Rept for LaSalle Unit 2,Cycle 8 ML20204C8141999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for LaSalle County Station,Units 1 & 2.With ML20199E4601998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for LaSalle County Station,Units 1 & 2.With ML20207C7371998-12-31031 December 1998 Annual Rept for LaSalle County Station for Jan 1998 Through Dec 1998 ML20205M7061998-12-31031 December 1998 Unicom Corp 1998 Summary Annual Rept. with ML20198B3801998-12-14014 December 1998 SER Accepting one-time Request for Relief from Certain Provisions of Section XI of ASME Boiler & Pressure Vessel Code,Per 10CFR50.55a for Certain Plant Safety/Relief Valves ML20206N2261998-12-0909 December 1998 LER 98-S03-00:on 981116,protected Area Was Entered Without Current Authorization for Unescorted Access Due to Programmatic Deficiency Error.Changed Badge Control Process ML20197K0981998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for LaSalle County Station,Unts 1 & 2.With ML20196B1441998-11-23023 November 1998 Safety Evaluation Accepting Licensee Response to GL 95-07, Pressure Locking & Thermal Bindings of Safety-Related Power-Operated Gate Valves ML20196A4191998-11-19019 November 1998 Safety Evaluation Accepting QA TR CE-1-A,Rev 66 Re Changes in Independent & Onsite Review Organization by Creating NSRB ML20195D3191998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for LaSalle County Station.With ML20154H6781998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for LaSalle County Nuclear Power Station,Units 1 & 2 ML20153D0191998-09-18018 September 1998 Part 21 Rept Re Defect in Gap Conductance Analyses for co- Resident BWR Fuel.Initially Reported on 980917.Corrective Analyses Performed Demonstrating That Current Operating Limits Bounding from BOC to Cycle Exposure of 8 Gwd/Mtu ML20153C7621998-09-18018 September 1998 Safety Evaluation Acceping NRC Bulletin 95-002, Unexpected Clogging of RHR Pump Strainer While Operating in Suppression Pool Cooling Mode ML20153C6771998-09-17017 September 1998 Part 21 Rept Re Defect Relative to MCPR Operating Limits as Impacted by Gap Conductance of co-resident BWR Fuel at Facilities.Operating Limit for LaSalle Unit 2 & Quad Cities Unit 2 Will Be Revised as Listed ML20151W0241998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for LaSalle County Station.With ML20237E2921998-08-21021 August 1998 Special Rept:On 980811,channel 5 of Lpms Became Inoperable. Caused by Channel Failed pre-amplifier Located Inside Primary Containment at Inboard Side of Electrical Penetration E-19.Initiated Repairs of Channel ML20237E2331998-08-21021 August 1998 Revised Pages of Section 20 of Rev 66 to CE-1-A, QA Topical Rept ML20237B4861998-07-31031 July 1998 Monthly Operating Repts for July 1998 for LaSalle County Nuclear Power Station Units 1 & 2 ML20236V7701998-07-31031 July 1998 Revised LaSalle Unit 1 Cycle 8 COLR & Reload Transient Analysis Results ML20236P8231998-07-14014 July 1998 Special Rept:From 980614-17,various Fire Rated Assemblies Were Inoperable for Period Greater than Seven Days.Caused by Test Equipment Being Routed Through Fire Doors.Established Fire Watches & on 980619 Assemblies Were Declared Operable ML20236N6751998-07-0909 July 1998 Part 21 & Deficiency Rept Re Notification of Potential Safety Hazard from Breakage of Cast Iron Suction Heads in Apkd Type Pumps.Caused by Migration of Suction Head Journal Sleeve Along Lower End of Pump Shaft.Will Inspect Pumps ML20236L8041998-07-0606 July 1998 Safety Evaluation Granting Licensee 980304 Request for Second 10-yr Interval Pump & Valve IST Program Plan,Rev 2, Including Changes to 2 ASME Boiler & Pressure Vessel Code Relief Requests Previously Submitted in Rev 1 ML20236P3611998-06-30030 June 1998 Monthly Operating Repts for June 1998 for LaSalle County Nuclear Power Station,Units 1 & 2 ML20249C4891998-06-22022 June 1998 Special Rept:On 980522,Fire Detection Zone 1-31 Was Noted out-of-service for More than 14 Days.Detection Sys Was Taken out-of-service on 980508 to Prevent False Alarms During Hot Work Activities.Sys Was Returned to Operable Status 980528 ML20248M3101998-05-31031 May 1998 Monthly Operating Repts for May 1998 for LaSalle County Nuclear Power Station,Units 1 & 2 ML20236V7771998-05-31031 May 1998 Rev 1 to 24A5180, Supplemental Reload Licensing Rept for LaSalle County Station Unit 1 Reload 7 Cycle 8 ML20217Q7041998-05-0404 May 1998 Safety Evaluation Accepting Util Request to Leave Leak Chase Channels Plugged During Performance of Containment ILRT ML20247M4491998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for LaSalle County Station ML20216F4941998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for LaSalle County Station,Units 1 & 2 ML20217N6581998-03-30030 March 1998 Special Rept on Fire Detection,Deluge Sys & Fire Rated Assemblies During Period of 980303-25.Established Fire Watches Until Affected Equipment Is Returned to Operable Status ML20216D9511998-02-28028 February 1998 Monthly Operating Repts for Feb 1998 for LaSalle County Station,Units 1 & 2 ML20247M4631998-02-28028 February 1998 Rev Monthly Operating Rept for Feb 1998 for LaSalle County Station ML20203D7241998-02-20020 February 1998 Special Rept:On 980118,Fire Detection Zones 1-18 & 2-18 Taken out-of-svc to Prevent False Alarms During Hot Work Activities on Auxiliary Electric Equipment Room Ventilation Sys.Fire Watches Will Remain in Place ML20202G9851998-01-31031 January 1998 Monthly Operating Repts for Jan 1998 for LaSalle County Station,Units 1 & 2 ML20199K1651998-01-23023 January 1998 Rev 65h to Topical Rept CE-1-A, Comm Ed QA Tr 1999-09-30
[Table view] |
Text
,
t- V e Commonwealth Edison
' i~' g . LaSalle County Nucl!ar Station -
Rural Route #1, Box 220 Marseilles, Illinois 61341.
Telephone 815/357-6761 March 2, 1990 I I
Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail station Pl-137.
Washington, D.C. 20555
Dear Sir:
l- Licensee Event Report E9-003-UO, Docket #050-373 is being l submitted to your office in accordance with l
10CFR50.73(a)(2)(iv).
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'O. J. Diederich S ation Manager l- LaSalle County station l- GJD/IGET/kg L . Enclosure-xc: Nuclear 1.icensing Administrator l NRC Resident Inspector
? NRC Region III Administrator INPO - Records Center r
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9003080087 900302 k.
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PDR ADOCK 05000373 .
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LICENSEE EVENT REPORT (LER) fim Rev 2.0 Facility Name (1) lDociet Nunt>er (2) Page (3)
LaSalle County Station Unit 1 01 51 01 01 01 31 71 3 1lof!0l5 Title (4) Reactor Core Isolation Cooling Isolation Signal During Wannup Due to Spurious High Stem f)pw Signal causen by Stem / water Mixture Trapped Between Isolation valves Event _Date (5) LER Neber (6D Report Date (7) Other Facilities involved (B)
Month Day Year Year Sequential ///j Revision Month Day Year Facility Names _
Docket Nunt>er(s)
//g/
f
// Nunt>cr ff
/// Nunt>er 01 51 01 01 Ol l 1 Ol 51 01 01 Ol l l
~ ~~
01 2 01 1 91 0 91 0 01013 01 0 0l3 01 2 9LO THIS REPORI 15 SUBM111ED PURSUANT TO THE RE%1REMEN15 0' 10CFR g) (Cnect one or more of the followine) (11) 1 20.402(b) _
20.A05(c) ,. X_ 50.73(a)(2)(iv) _
73.11(b)
POWER _ 20.405(4)(1)(1) __
50.36(c)(1) __
50.73(a)(2)(v) _
13.7)(c)
IIVEL 20.405(a)(1)(ll) 50.36(c)(2) 50.73(a)(2)(vii) Other (Specify 0l9!9 ,_ _ _ _
_(10) _ 20.405(a)(1)(iii) _
50.73(a)(2)(i) _
50.73(a)(2)(vill)(A) in Abstract
/ //,/f/,/,/,/,/,/,/,/,////j/,/,/,///,/,/, _
20.405(a)(1)(iv) _
50.73(a)(2)(li) _
50.73(a)(2)(viii)(B) below and in
///j//jfffffjfffffff//' 'f// 'f/}//
fj f /'ffj ,_
f// 20.405(a)(1)(v) ___
50.73(a)(2)(iii) _
50.73(a)(2)(x) Text) llCENSEE CONTACI FOR THIS f.ER (12) lame TEl[ PHONE NUpBER __
AREA CODE Mike fennyson. Technical Staff Engineer. extension 2704 _ _ _ _ _ _
8 l 1 15 315171-l6171611 COMPIE1E ONE llNE FOR EACH COMP 0NEW IAILURE EYSCRlBF,0_IN_THIS REPORT (13)
CAUSE SYSTEM COMP 0N MI MANUfAC- REPORIABlE CAUSE SYSIEM CDPPONENI MANUFAC- REPORTABLE TURER TO WPRDS_ TURER TO NPRDS B Bl N l l l l l l N I I l l l l l 1 1 I I I I I I 1 I I I I I SUPPLEMENTAL REPOR1 EXPECTED (14) Expected Month l Day l Year Submission Date (15) l I
-lyes (if ves, conqplete EXPECTID SUBMI5510N DATE) X l NO l l l 1 l ABSTRACT (Limit to 1400 spaces, i.e approxinutely fifteen single-space typewritten linas) (16)
On February 1,1990, at 1822 hours0.0211 days <br />0.506 hours <br />0.00301 weeks <br />6.93271e-4 months <br /> with Unit 1 in Operational Condition 1 (Run) at 99% power, the Reactor Core Isolation Cooling system (RCIC) received a Division 2 (inboard) isolation on RCIC high stem line flow.
Upon conpletion of preventative naintenance on the RCIC system, the system was being returned to Standby per LaSalle Operating Procedure, LOP -R14)4, "Turbina Trip Recovery arid Turbine Reset," when the inboard isolation valves (1E51-F063 and IE51-F076) isolated due to a spurious high steam flow signal.
1he RCIC stem line isolation was not a valid high stem flow signal. A steam / water mixture trapped between the inboard valves and the outboard valve was raileased into the piping downstre m of the outboard valve when it was opened. The surge from this release was sufficient to exceed the trip setpoint of the high flow isolation switches.
When the isolation signal was received, the inboard isolation valves and the outboard isolation valve were already closed. RCIC system piping integrity was verified and the isolation logic was reset. Wanning up of the RCIC system proceeded with no further incidents.
The RCIC system high stem flow isolation switches will be bypassed during the system return to service.
Before the outboard isolation valve (IE51-F008) is opened, the equalizing valves for instruments lE31-N013AA and IE31-N013BA will be opened. After the outboard isolation valve is opened, the equalizing valve will be closed, and warming of the stem lines will continue. This procedure will continue until a penrunent resolution is nade. A modification request which addresses a perwunent resolution to the problem of returning the RCIC system to service without isolations has been submitted for review.
This event is reportable to the Nuclear Regulatory Coninission as a Licensee Event Report in accordance with 10CFR50.73(a)(2)(iv) due to an Engineered Safety Feature actuation.
a
. Lirmrr EVENT REPORT (LER) TEX 1 CONilNUATION Fom Rev 2.0 4- _ FACILITV N4pui (1)- DOCKET NUpWER (2) LER 1RD9ER (6) Paae (3)
Year /// Sequential / Revision
- aber 7'/'/ Number //
w ile - etv Station unit 1 0 1 5 I o'I o 1 0 1 31 71 3 910 - 01013 -
01 0 01 2 0F 01 5 1 EXT Energy industry identification System (Ells) codes are identified in the text as [XX]
a PLANT AND SYSTEM IDEN11 FICA 110N General Electric - Bolling Idater Reactor-Energy Industry identification System (Ells) codes are identified in the text as [XX].
A. CONDITION PRICR 10 EVENT Unit (s): 1 Event Date: 2/1/90 Event Time: _ 1822 Hours Reactor Mode (s): 1 Mode (s) Nme: Run Power Level (s): 995
- 8. DESCRIP110N OF EVENT on February 1,1990, at 1822 hours0.0211 days <br />0.506 hours <br />0.00301 weeks <br />6.93271e-4 months <br /> the Reactor Core Isolation Cooling system (RCIC) [8N] received a Division 2 (inboard) isolation signal due to RCIC high steam line flow instrumentation. This isolation was not a valid high stem flow signal. This event occurred while Unit I was in Operational Condition 1~
(Run) at 995 power.
At the time of the event, RCIC stem line was being womed up following the completion of preventative maintenance to the RCIC system. The outboard RCic steam isolation valve (IE51-F008) and the inboard stem isolation valves (1E514063 and IE514076) were closed. Upon completion of the maintenance, RCIC was being returned to standby per LaSalle Operating Procedure, LOP-Al-04. . The Control Room Operator attsupted to slowly crack open the outboard isolation valve (IE51-F008), with the inboard valves closed.
Shortly after the outboard valve apparently lifted off of its seat, the Operator aoticed a step increase in RCIC stem line pressure downstrem of the outboard isolation valve and lamediately closed the ;
outboard valve. Within 4 seconds of the pressure increase the Olvision 2 inboard RCIC stem isolation -
valves (IE514063 and IE51-F076) received an isolation signal due to a high stem flow signal from the pressure differential switch PDS IE31-N0138A.
1he inboard stem isolation valves (IE51-F063 and IE514076) were closed at the time of the isolation signal, and the outboard isolation valve had already closed due to the operator's. response. After the isolation, the outboard valve was re-opened and the RCIC steam line was wamed in accordance with the sme procedure, LOP-RI-04, this time without incident.
The water which accumulated in the RCIC steam line piping between the inboard and outboard isolation
- valves during the perfonnance of the maintenance appears to affect the differential pressure instruments
-when it is pushed past one tap of the flow elbow by the trapped steam. The flow elbow cannot accurately measure flow in these circianstances due to the difference in fluid density between the taps.
This event is reportable to the Nuclear Regulatory Comnission as a Licensee Event Report in accordance with 10CFR50.73(a)(2)(lv) due to an Engineered Safety Feature actuation.
. - - .s g
LICEN3LE EVENT REPORT (LER) TEXT CONTINUATION Fonn Rev 2 0 ]
FAClEITY NAME (1) DOCKET NumER (2) lER NUSER (6) Pace (3) l Year /// Sequential fjf /jjj
// Revision ;
/// Nueer /// Nu6er LA$alle County Station Unit 1 0 1 5 1 0 1 0 1 0 l 31 71 3 910 -
010l3 - 01 0 01 3 0F 01 5 :
TEXT Energy Industry Identification System (Ells) codes are identified in the text as [XX]
C. APPARENT CAUSE OF EVENT The cause of the RCIC steam Ilne isolation was a spurious high stem flow signal generated when a steam / water mixture was admitted to the RCIC stem Inne downstrem of the outboard isolation valves IE514008.
Apparently the ste.im/ water mixture becme trapped downstrem of the inboard isolation valves (IE514076 and IE514063) and upstrem of the outboard isolation valve (IE514008) during the isolation of the system for preventative maintenance.
Upon reopening of the outboard isolation valve, the trapped stem expanded into the downstrem piping causing a surge of the steam / water mixture which actuated RCIC system high flow Isolation logic. The isolation logic for high RCIC steam line flow has a four second time delay built in to prevent spurious
[
isolation when RCIC fast starts. This four second change was approved as part of the corrective actions
! from previous isolations. The basis for the flow measurements used in the isolation logic is that the elbows would simse steam, not a steam / water mixture. The isolation was res2t satisfactorily after it l
occurred.
The cause of this isolation was that the spurious signal lasted greater than 4 seconds.
l D. SAFETY ANALYSIS OF EVENT Upon receiving the high stem line flow isolation signal, the RCIC stem line inboard isolation valves -
Isolated satisfactorily. This action was conservative from the standpoint of Primary Containment (PC)
[NH] Integrity.
1 All the valves were already closed. (IE514008 was closed due to Operator action prior to tne automatic closure signal.) Therefore the isolation function of these valves had ben met.
Since the valves were already closed, the isolation signal did not cause any challenges to the valves.
RCIC was already inoperable due to preventative maintenance. Satisfactory operatien of the high flow differential pressure switches was observed during subsequent testing.
Consequences of this event were minimal since the High Pressure Core Spray (HPCS) [BG] and other Emergency Core Cooling systems were fully operable.
E. CORRECTIVE ACTIONS RCIC system piping integrity was verifled and the isolation logic was reset. Wanning up of the RCIC system proceeded with no further incidents, and RCIC was returned to standby per LOP-RI-04 at 1907 hours0.0221 days <br />0.53 hours <br />0.00315 weeks <br />7.256135e-4 months <br /> on February 1, 1990.
LICENSEE EVENT REPORT (tER) TEXT CONTINUATION Fom Rev 2.0 FACILITY NAME (1) DOCKET NU SER (2) LER WUSER (6) _ , Pace (3)
Year- /// Sequential t,/,/ Revision fff
/// Wusber W/ thsiber 1
LaSalle County Station Unit 1 0 l 5 1 0 1 0 1 0 l 31 71 3 9l0 -
010l3 - 01 0 01 4 0F 01 5 F TEXT Energy Industry identification System (Ells) codes are identified in the text as [XX) i E. CORRECTIVE ACTIONS (Continued)
Similar events occurred on May 15,1999, at 2156 hours0.025 days <br />0.599 hours <br />0.00356 weeks <br />8.20358e-4 months <br /> and on August 10, 1989, following coupletion of Unit 1 Stem Line Flow RCIC isolation Functional Test. Action item Record (AIR) 373-200-8944801 was initiated to track completion of the corrective actions for the events. A sunnary of the corrective actions taken after the RCIC isolations follow:
LaSalle Special Test, LST 89-019, Pressure / Differential Pressure Observation of RCIC Stem Line i' H141ow Isolation Switch, was perforined to observe the pressure and differential pressure transients, and also ta detemine whether another isolation would occur on returning RCIC to '
Standby per LaSalle Operating Procedure, LOP-RI-04. There was no RCIC isolation when the system was returned to Standby.
l A second special test was perfonned during return to Standby following isolation for maintenance of the RCIC high stem flow instruments. The pressure differential switches, PDS I IE31-N013AA/A8/8A/98, the time delay relays associated with these switches, and the RCIC stem I header pressure indicator IL51-N007 downstrem of outboard isolation valve IE51-F008 were monitored during system isolation, and on return to standby.
l l During the RCIC system return to Standby there was no RCIC isolation. The test equipment remained
- ' connected and was nonitored for three weeks to detemine the possible drift that would occur to the pressure differential switches while RCIC was in service. It was detemined that the drift in the switches was not sufficient to contribute to a RCIC system isolation during return to a Standby condition.
The pressure differential switches PDS lE31-N007A8/BB and PDS IE31-W013nB/BB have been placed out of service until they are pennanenth, removed by modification M01-1-88-052. These sw!tches are piped "In reverse" and cannot sense a legitimate high stem flow condition.
l l LaSalle Special test, LST 89-062 was perfonned again on .luly II,1989 in conjunction with a RCIC instrument surveillance. Upon RCIC return to service there was no RCIC' isolation.
After evaluation of the tests, LaSalle Operating Procedure, LOP-RI-03 was revised. The revision instructed the Control Room Operators to reduce the stem line pressure downstream of inboard-isolation valve IL51-F063 to 400 psig before closing outboard isolation valve IE51-F008. The pressure reduction in the steam line would be accomplished by waiting a period of 45 to 50 minutes after closure of the inboard isolation valve.
All LaSalle Instrument surveillances and procedures that required the isolation of the RCIC system have been revised to reflect that all system isolations would be perfonned in accordance with the l, specific Operating procedure that is discussed in the above paragraph.
The setpoint for the time delay relays have been increased to 4 seconds. A Drawing Change Request
- was submitted for the schematic drawings as they currently indicate the time delay relays actuate at 3 seconds. The Technical Specification limit is 5 seconds. The completion of this corrective
, action will be tracked in AIR 373-200-89-07202.
L L
'F
=' . ;*
. LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Form Rev 2.0 FACILITY NAME (1) DOCKE1 NUSER (2) LER NU SER (6) Pace (3)
Year /// Sequential /j//j Revision fff f
/// Nueer /// Nueer LaSalle County Station Unit 1 0 l 5 1 0 1 0 1 0 l 31 71 3 910 - 010l3 -
0l0 015 0F 01 5 1EX1 Energy Industry Identification System (Ells) codes are identified in the text as (XX]
E. CORHEC'lVE AC110NS (Continued) 10 prevent spurlous isolations, LOP-R144 and LOP-RI-05, " Preparation for Standby Operation of the RCIC System," will be revised to bypass the RCIC system high stem flow isolation switches will be bypassed during the system return to service. Before the outboard isolation valve (IE51-F008) is opened, the equalizing valves for instruments IE31-N013AA and IE31-N0138A will be opened. After the outboard isolation valve is opened, the equalizing valve will be closed, and warming of the steam lines will continue. This procedure will continue until a pennanent resolution is made. A modification request which addresses a pennanent resolution to the problem of returning the RCIC system to service without isolations has been submitted for review. Action item Record (AIR) 373-200-90 01501 will track conpletion of this review.
F. PREVIOUS EVENTS LER Number iltle 373/85-022-00 RCic Steam Line High Flow Isolation During Warmup 373/84-060-00 RCIC Stem Line Differential Pressure High Isolation 373/83-122/03L RCIC Steam Line Isolation During Wannup 373/89-018-00 RCIC isolation During Wanaup Due to Spurious High Steam Flow Signal 373-89-022-00 RCIC isolation During Wannup G. COMPONENT FAILURE DATA None.
. _ . _ - _ - _ .