|
---|
Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20029D0261994-04-22022 April 1994 LER 94-002-00:on 940329,inadvertent Automatic Closure of Primary Containment Isolation Valves & ESF Actuations Occurred Due to Malfunctioning Handswitch.Caused by Weak Electrical Contact Spring.Handswitch replaced.W/940422 Ltr ML20046B4961993-07-30030 July 1993 LER 93-008-00:on 930627,MCR Annunciator Alarmed Indicating That Outside Atmosphere Reactor Encl (Re) Negative Differential Pressure Decayed Due to Failure of Normal Re Ventilation Fan Motor.Subj Fan replaced.W/930730 Ltr ML20046C3961993-07-30030 July 1993 LER 92-011-01:on 920605,discovered Potential Physical Electrical Separation Deficiency in Panel 10C790.Plant Electrical Maint I&C Technicians Received Training on Electrical Separation Requirements ML20046B5051993-07-30030 July 1993 LER 91-015-01:on 910912,HPCI Sys Discovered to Be in Degraded Condition When HPCI Turbine Steam Supply Valve Failed to Fully Open.Recommendations of EPRI Improved MOV Lubricant Program implemented.W/930730 Ltr ML20046B5001993-07-30030 July 1993 LER 93-008-00:on 930630,determined That TS SR on Fire Rated Assemblies Not Satisfied Due to Personnel Error During Procedure Preparation.Surveillance Test Procedure ST-7-022-922-0 Will Be revised.W/930730 Ltr ML20046A4431993-07-19019 July 1993 LER 93-007-00:on 930617,alarm Indicated TIP Sys Shear Valve Was Inoperable.Cause Interminate.Isolated Occurrence. W/930719 Ltr ML20045D3931993-06-21021 June 1993 LER 93-007-00:on 930521,primary Containment Isolation Valve Inoperable & TS Action Statement & SR Not Implemented in Required Time.Caused by Personnel Error.Ltr Issued to Personnel Emphasizing Requirement ML20044E7431993-05-20020 May 1993 LER 93-002-01:on 930124,discovered That EDG Inoperable Since 930119 Due to Improperly Connected Wires in Circuit Breaker. Wires Restored to Proper Position & Tested Satisfactorily. Procedural & Training Changes Also Implemented ML20044D1761993-05-0707 May 1993 LER 87-028-01:on 870610,hourly Fire Watch Required by TS 3.7.7 Not Performed Due to Personnel Error.Plant Security Organization Accepted Responsibility for Hourly Firewatch Patrol Required by Ts,Effective 930104 ML20044C9231993-05-0505 May 1993 LER 93-004-00:on 930405,primary Containment & Reactor Vessel Isolation Control Sys Actuation Occurred During Test of NSSSS-refueling Area Ventilation Exhaust Duct.Caused by Personnel Error.Technician counseled.W/930505 Ltr ML20024H0901991-05-10010 May 1991 LER 91-007-00:on 910410,handling of Control Rod Prohibited by Tech Spec Surveillance Requirements 4.9.6.3b.Caused by Inadequate Procedure.Maint Procedure Changed Deleting Provisions to Reposition Mechanical stop.W/910510 Ltr ML20024G6981991-04-22022 April 1991 LER 91-003-00:on 910324,inadvertent Actuation of Reactor Protection Sys Occurred.Caused by Personnel Error.Procedural Guidance Developed,Shift Training Bulletin Issued & Operator Requalification Training Module revised.W/910422 Ltr ML20029A8251991-02-27027 February 1991 LER 91-005-00:on 910130,pressure Differential Switch Restored Incorrectly,Causing Spurious Drywell Pressure Signal & ESF Actuation.Caused by Personnel Error.Personnel Counseled & Warning Labels added.W/910227 Ltr ML20029A7101991-02-22022 February 1991 LER 91-004-00:on 910123,determined That TS Section 3.3.7.5 Surveillance Requirements Not Satisfied for Fuel Zone Level & Neutron Flux Instrumentation.Caused by Misinterpretation of Ts.Calibr Procedures revised.W/910222 Ltr ML20028H7121991-01-22022 January 1991 LER 90-035-00:on 901224,14 Valves Associated W/Various Sys & Required to Perform Function of Isolating Primary Containment Determined Inoperable.Caused by Installation Error During Initial const.W/910122 Ltr ML20028H6791991-01-18018 January 1991 LER 91-002-00:on 910109,replacement Cassette Drive Unit to Replace Inoperable Seismic Monitoring Sys Not Received by 910109,rendering Sys Inoperable for More than 30 Days.Caused by Grit on Gear.Sys repaired.W/910118 Ltr ML20024F7361990-12-0707 December 1990 LER 90-025-00:on 901110,spurious LOCA Signal Resulted in ESF actuations.W/901207 Ltr ML20028G9221990-09-26026 September 1990 LER 90-017-00:on 900828,ESF Actuation of Primary Containment & Reactor Vessel Isolation Control Sys Occurred.Caused by Technician Inadvertently Shorting Power Supply During Installation of Test Jack.Blown Fuse replaced.W/900926 Ltr ML20044A9761990-07-12012 July 1990 LER 90-013-00:on 900611,dc Distribution Sys Identified to Have Inadequate Isolation Capability Between Class IE & non-Class IE Components.Cause of Event Under Investigation. Hourly Fire Watches Established Until 900626.W/900712 Ltr ML20043C5231990-06-0101 June 1990 LER 90-003-01:on 900208,HPCI Sys Isolation Valve Inadvertently Isolated During Surveillance Test.Caused by Both Channels of Isolation Logic Being in Tripped Condition at Same Time.Isolation of HPCI Sys reset.W/900601 Ltr ML20043C3211990-05-30030 May 1990 LER 90-012-00:on 900426,inoperability of RHR Sys Modes Occurred Due to Physical Separation Deficiencies.Caused by Drawing Deficiency Resulting in Installation Error During Original Const.Nonclass 1E Cable sleeved.W/900530 Ltr ML20043B1331990-05-21021 May 1990 LER 90-011-00:on 900420,discovered That Emergency Svc Water Pump B Discharge Check Valve Not Preventing Reverse Flow. Caused by Personnel Error in That Actuating Arm Incorrectly Assembled.Actuating Arm repositioned.W/900521 Ltr ML20043B1311990-05-18018 May 1990 LER 90-006-01:on 900223,determined That Capability to Activate Emergency Public Notification Sys Sirens from Counties Lost from 900112-0205.Caused by Disconnection of Phone Lines.Lines Reconnected for All counties.W/900518 Ltr ML20043A7651990-05-17017 May 1990 LER 90-008-00:on 900417,HPCI Sys Isolation & Inoperability Occurred Due to Failure of Differential Pressure Transmitter.Cause of Transmittal Failure Under Investigation.Transmitter Returned to mfg.W/900517 Ltr ML20043A6321990-05-15015 May 1990 LER 89-060-01:on 891212,standby Gas Treatment Sys Charcoal Filter Discovered in Degraded Condition W/Possible Bypass Leakage Paths.Similar Condition Discovered on 891218.Caused by Holes in Charcoal Filter assemblies.W/900515 Ltr ML20043A4261990-05-15015 May 1990 LER 90-010-00:on 900415,ESF Actuation Occurred Closing Three Containment Isolation Valves for Analyzers.Cause Unknown. Isolation Reset,Analyzers Returned to Svc & Voltmeter Not Being Used Pending Determination of cause.W/900515 Ltr ML20042G0521990-05-0404 May 1990 LER 90-009-00:on 900405,control Room Chlorine Isolation of Habitability Control Room Isolation Sys & ESF Initiated. Caused by Failure of B Toxic Gas Detector & False Signal from Untested Analyzer.Detector replaced.W/900504 Ltr ML20012C9361990-03-12012 March 1990 LER 90-005-00:on 900211,no Fire Watch Insps for Rooms 103, 114 & 117 on Elevation 177 Ft in Reactor Encl Performed by Personnel.Caused by Personnel Error.Person Involved Disciplined.Training Program improved.W/900312 Ltr ML20012C5541990-03-12012 March 1990 LER 90-004-00:on 900209,station Personnel Discovered That on 890708,22-s Reactor Power Transient Occurred in Which Reactor Thermal Power Changed by More than 15% of Rated Thermal Power in 1 H.Procedure revised.W/900312 Ltr ML20012C7071990-03-12012 March 1990 LER 90-003-00:on 900208,HPCI Sys Inboard Isolation Valve Inadvertently Isolated & Closed When One Channel of Isolation Logic Tripped.Caused by Degradation of Darlington Output Transistor.Isolation reset.W/900312 Ltr ML20011F7911990-02-26026 February 1990 LER 90-002-00:on 900125,identified That Main Control Room Ventilation Sys Outside Design Basis.Caused by Misapplication of Design Basis Assumptions.No Immediate Actions Taken as Existing Procedures adequate.W/900226 Ltr ML20006E4271990-02-0909 February 1990 LER 90-001-00:on 900122,discovered That Monthly Instrument Channel Functional Test for RCIC Steam Supply Pressure Low Missed.Caused by Deficiency in Computer Program Used to Schedule Tests.Computer Program revised.W/900209 Ltr ML20006E3451990-02-0808 February 1990 LER 90-003-00:on 900112,primary Containment & Reactor Vessel Isolation Control Sys Isolation Signals Initiated, Closing Inboard & Outboard Isolation Valves for Rwcu.Caused by Lifting Relief Valve.Opening Time reset.W/900208 Ltr ML20006E2851990-02-0707 February 1990 LER 90-002-00:on 900105,containment H2/O2 Analyzer Declared Inoperable During Containment Inerting.Caused by Reversed Tubing Connections in Installation of Analyzer Due to Mislabeling.Analyzer restored.W/900207 Ltr ML20006D5171990-02-0707 February 1990 LER 90-001-00:on 900108,Tech Spec Violation & Reactor Encl Ventilation Isolation Occurred.Caused by Personnel Error. Chief Operator Counseled on Importance of Communicating All Pertinent info.W/900207 Ltr ML20006A8801990-01-19019 January 1990 LER 89-015-00:on 891223 & 24,problem W/Reactor Protection Sys (Rps)/Uninterruptable Power Supply Static Inverter Caused Loss of Power to RPS Panel.Caused by Failure of Gate Drive Boost Card.Isolations reset.W/900119 Ltr ML20005F9441990-01-10010 January 1990 LER 89-060-00:on 891212,standby Gas Treatment Sys Charcoal Filter a Discovered to Be Degraded W/Possible Bypass Leakage Paths.On 891218,filter B Found W/Similar Condition.Caused by Failure of Spot Welds.Filters repaired.W/900110 Ltr ML20005E6841990-01-0303 January 1990 LER 89-059-00:on 891206,instrumentation & Controls Technician Inadvertently Grounded Test Jack,Resulting in Blown Fuse.Caused by Personnel Error.Fuse Replaced. Technicians counseled.W/900103 Ltr ML20042D1961989-12-29029 December 1989 LER 89-009-02:on 890820 & 0925,RCIC Sys Injections Into RCS Occurred During Startup Test.From 891023-26,three HPCI Sys Injections Into RCS Occurred During Test.Injections Anticipated.Startup Tests performed.W/891229 Ltr ML20005E3301989-12-29029 December 1989 LER 89-014-00:on 891202,unexpected Actuation of Primary Containment & Reactor Vessel Isolation Control Sys Occurred. Caused by Insufficient Guidance in General Plant Procedure. Appropriate Procedures Reviewed & revised.W/891229 Ltr ML20005E0961989-12-26026 December 1989 LER 89-058-00:on 891123,actuation of Group III Primary Containment & Reactor Vessel Isolation Control Sys Resulted in Automatic Isolation of Rwcu.Caused by Failure of Flow Summer Card.Card replaced.W/891226 Ltr ML20011D2291989-12-19019 December 1989 LER 89-057-00:on 891120,refuel Floor Secondary Containment Isolated on Low Flow Differential Pressure,Causing Initiation of Standby Gas Treatment Sys.Caused by Severe Storm.Normal Ventilation Restored to floor.W/891219 Ltr ML19332F8631989-12-13013 December 1989 LER 89-056-00:on 891119,unexpected Nuclear Steam Supply Shutoff Sys Group Iii,Div 4 Isolation Initiated ESF Actuation.Caused by Defective read-set Selector Switch. Switch repositioned.W/891213 Ltr ML19332F7761989-12-11011 December 1989 LER 89-013-00:on 891110,reactor Scram Occurred Following Main Turbine Trip,Causing Initiation Signals on HPCI & RCIC Sys Due to Spiking of Level Transformers.Caused by Design Error.Hpci Turbine secured.W/891211 Ltr ML19332F7751989-12-11011 December 1989 LER 89-012-00:on 891110,RWCU Sys Differential Flow Oscillations Observed While Placing RWCU 2A Filter/ Demineralizer Into Svc.Caused by Leakage in Reactor HX Tube Side Safety Relief Valve.Valve removed.W/891211 Ltr ML19332F2961989-11-29029 November 1989 LER 89-009-01:on 890820,eight RCIC Sys Injections Into RCS Occurred Under Purview of Facility start-up Test Program. Caused by Abnormal Plant Conditions Requiring Safety Sys Actuations.Rcic & HPCI Sys Tests completed.W/891129 Ltr ML19332D6331989-11-27027 November 1989 LER 89-011-00:on 891027,outboard Nuclear Steam Supply Shutoff Sys Isolation Valves Isolated.Caused by Personnel Error Due to Lack of Attention to Detail by Technicians. Event Discussed at All Hands meeting.W/891127 Ltr ML19332D6251989-11-27027 November 1989 LER 89-055-00:on 891025,reactor Protection Sys 1A Shunt Trip Breaker Tripped on Undervoltage,Causing Loss of Power to Distribution Panel 1AY160 & ESF Isolation.Caused by Relief Valve Failures.Isolations reset.W/891127 Ltr ML19332C1781989-11-17017 November 1989 LER 89-053-00:on 891022,control Room Personnel Manually Initiated Ventilation Sys Chlorine Isolation,Esf.Caused by High Vinyl Chloride Concentration in Outside Air Intake Plenum.Special Event Procedure implemented.W/891117 Ltr ML19332B9841989-11-15015 November 1989 LER 89-054-01:on 891025,discovered That Daily Channel Check Surveillance Requirement for Channel D High Level Trip Not Met.Caused by Procedural Deficiency Since Initial Plant Operation.Associated Log Procedures revised.W/891115 Ltr 1994-04-22
[Table view] Category:RO)
MONTHYEARML20029D0261994-04-22022 April 1994 LER 94-002-00:on 940329,inadvertent Automatic Closure of Primary Containment Isolation Valves & ESF Actuations Occurred Due to Malfunctioning Handswitch.Caused by Weak Electrical Contact Spring.Handswitch replaced.W/940422 Ltr ML20046B4961993-07-30030 July 1993 LER 93-008-00:on 930627,MCR Annunciator Alarmed Indicating That Outside Atmosphere Reactor Encl (Re) Negative Differential Pressure Decayed Due to Failure of Normal Re Ventilation Fan Motor.Subj Fan replaced.W/930730 Ltr ML20046C3961993-07-30030 July 1993 LER 92-011-01:on 920605,discovered Potential Physical Electrical Separation Deficiency in Panel 10C790.Plant Electrical Maint I&C Technicians Received Training on Electrical Separation Requirements ML20046B5051993-07-30030 July 1993 LER 91-015-01:on 910912,HPCI Sys Discovered to Be in Degraded Condition When HPCI Turbine Steam Supply Valve Failed to Fully Open.Recommendations of EPRI Improved MOV Lubricant Program implemented.W/930730 Ltr ML20046B5001993-07-30030 July 1993 LER 93-008-00:on 930630,determined That TS SR on Fire Rated Assemblies Not Satisfied Due to Personnel Error During Procedure Preparation.Surveillance Test Procedure ST-7-022-922-0 Will Be revised.W/930730 Ltr ML20046A4431993-07-19019 July 1993 LER 93-007-00:on 930617,alarm Indicated TIP Sys Shear Valve Was Inoperable.Cause Interminate.Isolated Occurrence. W/930719 Ltr ML20045D3931993-06-21021 June 1993 LER 93-007-00:on 930521,primary Containment Isolation Valve Inoperable & TS Action Statement & SR Not Implemented in Required Time.Caused by Personnel Error.Ltr Issued to Personnel Emphasizing Requirement ML20044E7431993-05-20020 May 1993 LER 93-002-01:on 930124,discovered That EDG Inoperable Since 930119 Due to Improperly Connected Wires in Circuit Breaker. Wires Restored to Proper Position & Tested Satisfactorily. Procedural & Training Changes Also Implemented ML20044D1761993-05-0707 May 1993 LER 87-028-01:on 870610,hourly Fire Watch Required by TS 3.7.7 Not Performed Due to Personnel Error.Plant Security Organization Accepted Responsibility for Hourly Firewatch Patrol Required by Ts,Effective 930104 ML20044C9231993-05-0505 May 1993 LER 93-004-00:on 930405,primary Containment & Reactor Vessel Isolation Control Sys Actuation Occurred During Test of NSSSS-refueling Area Ventilation Exhaust Duct.Caused by Personnel Error.Technician counseled.W/930505 Ltr ML20024H0901991-05-10010 May 1991 LER 91-007-00:on 910410,handling of Control Rod Prohibited by Tech Spec Surveillance Requirements 4.9.6.3b.Caused by Inadequate Procedure.Maint Procedure Changed Deleting Provisions to Reposition Mechanical stop.W/910510 Ltr ML20024G6981991-04-22022 April 1991 LER 91-003-00:on 910324,inadvertent Actuation of Reactor Protection Sys Occurred.Caused by Personnel Error.Procedural Guidance Developed,Shift Training Bulletin Issued & Operator Requalification Training Module revised.W/910422 Ltr ML20029A8251991-02-27027 February 1991 LER 91-005-00:on 910130,pressure Differential Switch Restored Incorrectly,Causing Spurious Drywell Pressure Signal & ESF Actuation.Caused by Personnel Error.Personnel Counseled & Warning Labels added.W/910227 Ltr ML20029A7101991-02-22022 February 1991 LER 91-004-00:on 910123,determined That TS Section 3.3.7.5 Surveillance Requirements Not Satisfied for Fuel Zone Level & Neutron Flux Instrumentation.Caused by Misinterpretation of Ts.Calibr Procedures revised.W/910222 Ltr ML20028H7121991-01-22022 January 1991 LER 90-035-00:on 901224,14 Valves Associated W/Various Sys & Required to Perform Function of Isolating Primary Containment Determined Inoperable.Caused by Installation Error During Initial const.W/910122 Ltr ML20028H6791991-01-18018 January 1991 LER 91-002-00:on 910109,replacement Cassette Drive Unit to Replace Inoperable Seismic Monitoring Sys Not Received by 910109,rendering Sys Inoperable for More than 30 Days.Caused by Grit on Gear.Sys repaired.W/910118 Ltr ML20024F7361990-12-0707 December 1990 LER 90-025-00:on 901110,spurious LOCA Signal Resulted in ESF actuations.W/901207 Ltr ML20028G9221990-09-26026 September 1990 LER 90-017-00:on 900828,ESF Actuation of Primary Containment & Reactor Vessel Isolation Control Sys Occurred.Caused by Technician Inadvertently Shorting Power Supply During Installation of Test Jack.Blown Fuse replaced.W/900926 Ltr ML20044A9761990-07-12012 July 1990 LER 90-013-00:on 900611,dc Distribution Sys Identified to Have Inadequate Isolation Capability Between Class IE & non-Class IE Components.Cause of Event Under Investigation. Hourly Fire Watches Established Until 900626.W/900712 Ltr ML20043C5231990-06-0101 June 1990 LER 90-003-01:on 900208,HPCI Sys Isolation Valve Inadvertently Isolated During Surveillance Test.Caused by Both Channels of Isolation Logic Being in Tripped Condition at Same Time.Isolation of HPCI Sys reset.W/900601 Ltr ML20043C3211990-05-30030 May 1990 LER 90-012-00:on 900426,inoperability of RHR Sys Modes Occurred Due to Physical Separation Deficiencies.Caused by Drawing Deficiency Resulting in Installation Error During Original Const.Nonclass 1E Cable sleeved.W/900530 Ltr ML20043B1331990-05-21021 May 1990 LER 90-011-00:on 900420,discovered That Emergency Svc Water Pump B Discharge Check Valve Not Preventing Reverse Flow. Caused by Personnel Error in That Actuating Arm Incorrectly Assembled.Actuating Arm repositioned.W/900521 Ltr ML20043B1311990-05-18018 May 1990 LER 90-006-01:on 900223,determined That Capability to Activate Emergency Public Notification Sys Sirens from Counties Lost from 900112-0205.Caused by Disconnection of Phone Lines.Lines Reconnected for All counties.W/900518 Ltr ML20043A7651990-05-17017 May 1990 LER 90-008-00:on 900417,HPCI Sys Isolation & Inoperability Occurred Due to Failure of Differential Pressure Transmitter.Cause of Transmittal Failure Under Investigation.Transmitter Returned to mfg.W/900517 Ltr ML20043A6321990-05-15015 May 1990 LER 89-060-01:on 891212,standby Gas Treatment Sys Charcoal Filter Discovered in Degraded Condition W/Possible Bypass Leakage Paths.Similar Condition Discovered on 891218.Caused by Holes in Charcoal Filter assemblies.W/900515 Ltr ML20043A4261990-05-15015 May 1990 LER 90-010-00:on 900415,ESF Actuation Occurred Closing Three Containment Isolation Valves for Analyzers.Cause Unknown. Isolation Reset,Analyzers Returned to Svc & Voltmeter Not Being Used Pending Determination of cause.W/900515 Ltr ML20042G0521990-05-0404 May 1990 LER 90-009-00:on 900405,control Room Chlorine Isolation of Habitability Control Room Isolation Sys & ESF Initiated. Caused by Failure of B Toxic Gas Detector & False Signal from Untested Analyzer.Detector replaced.W/900504 Ltr ML20012C9361990-03-12012 March 1990 LER 90-005-00:on 900211,no Fire Watch Insps for Rooms 103, 114 & 117 on Elevation 177 Ft in Reactor Encl Performed by Personnel.Caused by Personnel Error.Person Involved Disciplined.Training Program improved.W/900312 Ltr ML20012C5541990-03-12012 March 1990 LER 90-004-00:on 900209,station Personnel Discovered That on 890708,22-s Reactor Power Transient Occurred in Which Reactor Thermal Power Changed by More than 15% of Rated Thermal Power in 1 H.Procedure revised.W/900312 Ltr ML20012C7071990-03-12012 March 1990 LER 90-003-00:on 900208,HPCI Sys Inboard Isolation Valve Inadvertently Isolated & Closed When One Channel of Isolation Logic Tripped.Caused by Degradation of Darlington Output Transistor.Isolation reset.W/900312 Ltr ML20011F7911990-02-26026 February 1990 LER 90-002-00:on 900125,identified That Main Control Room Ventilation Sys Outside Design Basis.Caused by Misapplication of Design Basis Assumptions.No Immediate Actions Taken as Existing Procedures adequate.W/900226 Ltr ML20006E4271990-02-0909 February 1990 LER 90-001-00:on 900122,discovered That Monthly Instrument Channel Functional Test for RCIC Steam Supply Pressure Low Missed.Caused by Deficiency in Computer Program Used to Schedule Tests.Computer Program revised.W/900209 Ltr ML20006E3451990-02-0808 February 1990 LER 90-003-00:on 900112,primary Containment & Reactor Vessel Isolation Control Sys Isolation Signals Initiated, Closing Inboard & Outboard Isolation Valves for Rwcu.Caused by Lifting Relief Valve.Opening Time reset.W/900208 Ltr ML20006E2851990-02-0707 February 1990 LER 90-002-00:on 900105,containment H2/O2 Analyzer Declared Inoperable During Containment Inerting.Caused by Reversed Tubing Connections in Installation of Analyzer Due to Mislabeling.Analyzer restored.W/900207 Ltr ML20006D5171990-02-0707 February 1990 LER 90-001-00:on 900108,Tech Spec Violation & Reactor Encl Ventilation Isolation Occurred.Caused by Personnel Error. Chief Operator Counseled on Importance of Communicating All Pertinent info.W/900207 Ltr ML20006A8801990-01-19019 January 1990 LER 89-015-00:on 891223 & 24,problem W/Reactor Protection Sys (Rps)/Uninterruptable Power Supply Static Inverter Caused Loss of Power to RPS Panel.Caused by Failure of Gate Drive Boost Card.Isolations reset.W/900119 Ltr ML20005F9441990-01-10010 January 1990 LER 89-060-00:on 891212,standby Gas Treatment Sys Charcoal Filter a Discovered to Be Degraded W/Possible Bypass Leakage Paths.On 891218,filter B Found W/Similar Condition.Caused by Failure of Spot Welds.Filters repaired.W/900110 Ltr ML20005E6841990-01-0303 January 1990 LER 89-059-00:on 891206,instrumentation & Controls Technician Inadvertently Grounded Test Jack,Resulting in Blown Fuse.Caused by Personnel Error.Fuse Replaced. Technicians counseled.W/900103 Ltr ML20042D1961989-12-29029 December 1989 LER 89-009-02:on 890820 & 0925,RCIC Sys Injections Into RCS Occurred During Startup Test.From 891023-26,three HPCI Sys Injections Into RCS Occurred During Test.Injections Anticipated.Startup Tests performed.W/891229 Ltr ML20005E3301989-12-29029 December 1989 LER 89-014-00:on 891202,unexpected Actuation of Primary Containment & Reactor Vessel Isolation Control Sys Occurred. Caused by Insufficient Guidance in General Plant Procedure. Appropriate Procedures Reviewed & revised.W/891229 Ltr ML20005E0961989-12-26026 December 1989 LER 89-058-00:on 891123,actuation of Group III Primary Containment & Reactor Vessel Isolation Control Sys Resulted in Automatic Isolation of Rwcu.Caused by Failure of Flow Summer Card.Card replaced.W/891226 Ltr ML20011D2291989-12-19019 December 1989 LER 89-057-00:on 891120,refuel Floor Secondary Containment Isolated on Low Flow Differential Pressure,Causing Initiation of Standby Gas Treatment Sys.Caused by Severe Storm.Normal Ventilation Restored to floor.W/891219 Ltr ML19332F8631989-12-13013 December 1989 LER 89-056-00:on 891119,unexpected Nuclear Steam Supply Shutoff Sys Group Iii,Div 4 Isolation Initiated ESF Actuation.Caused by Defective read-set Selector Switch. Switch repositioned.W/891213 Ltr ML19332F7761989-12-11011 December 1989 LER 89-013-00:on 891110,reactor Scram Occurred Following Main Turbine Trip,Causing Initiation Signals on HPCI & RCIC Sys Due to Spiking of Level Transformers.Caused by Design Error.Hpci Turbine secured.W/891211 Ltr ML19332F7751989-12-11011 December 1989 LER 89-012-00:on 891110,RWCU Sys Differential Flow Oscillations Observed While Placing RWCU 2A Filter/ Demineralizer Into Svc.Caused by Leakage in Reactor HX Tube Side Safety Relief Valve.Valve removed.W/891211 Ltr ML19332F2961989-11-29029 November 1989 LER 89-009-01:on 890820,eight RCIC Sys Injections Into RCS Occurred Under Purview of Facility start-up Test Program. Caused by Abnormal Plant Conditions Requiring Safety Sys Actuations.Rcic & HPCI Sys Tests completed.W/891129 Ltr ML19332D6331989-11-27027 November 1989 LER 89-011-00:on 891027,outboard Nuclear Steam Supply Shutoff Sys Isolation Valves Isolated.Caused by Personnel Error Due to Lack of Attention to Detail by Technicians. Event Discussed at All Hands meeting.W/891127 Ltr ML19332D6251989-11-27027 November 1989 LER 89-055-00:on 891025,reactor Protection Sys 1A Shunt Trip Breaker Tripped on Undervoltage,Causing Loss of Power to Distribution Panel 1AY160 & ESF Isolation.Caused by Relief Valve Failures.Isolations reset.W/891127 Ltr ML19332C1781989-11-17017 November 1989 LER 89-053-00:on 891022,control Room Personnel Manually Initiated Ventilation Sys Chlorine Isolation,Esf.Caused by High Vinyl Chloride Concentration in Outside Air Intake Plenum.Special Event Procedure implemented.W/891117 Ltr ML19332B9841989-11-15015 November 1989 LER 89-054-01:on 891025,discovered That Daily Channel Check Surveillance Requirement for Channel D High Level Trip Not Met.Caused by Procedural Deficiency Since Initial Plant Operation.Associated Log Procedures revised.W/891115 Ltr 1994-04-22
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217D1211999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Lgs,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 ML20212A8861999-09-13013 September 1999 Safety Evaluation Authorizing First & Second 10 Yr Interval Inservice Insp Plan Requestss for Relief RR-01 ML20212A4481999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Limerick Generating Station,Units 1 & 2.With ML20211E9891999-08-20020 August 1999 LGS Unit 2 Summary Rept for 970228 to 990525 Periodic ISI Rept Number 5 ML20210L7051999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Limerick Generating Station,Units 1 & 2.With ML20209G0211999-06-30030 June 1999 GE-NE-B13-02010-33NP, Evaluation of Limerick Unit 2 Shroud Cracking for at Least One Fuel Cycle of Operation ML20209D7741999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Limerick Generating Station,Units 1 & 2 ML20207H8331999-05-31031 May 1999 Non-proprietary Rev 0 to 1H61R, LGS - Unit 2 Core Shroud Ultrasonic Exam ML20195G4651999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Lgs,Units 1 & 2 ML20209D7791999-05-31031 May 1999 Revised Monthly Operating Repts for May 1999 for Limerick Generating Station,Units 1 & 2 ML20195B3021999-05-0606 May 1999 Rev 0 to PECO-COLR-L2R5, COLR for Lgs,Unit 2 Reload 5 Cycle 6 ML20206N2901999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Limerick Generating Station,Units 1 & 2.With ML20195G4761999-04-30030 April 1999 Revised Monthly Operating Repts for Apr 1999 for Lgs,Units 1 & 2 ML20206D8971999-04-22022 April 1999 Rev 2 to PECO-COLR-L1R7, COLR for Lgs,Unit 2 Reload 7, Cycle 8 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 ML20205N9311999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Limerick Generating Station,Units 1 & 2.With ML20204G9851999-03-11011 March 1999 Safety Evaluation Re Revised Emergency Action Levels for Limerick Generating Station,Units 1 & 2 ML20207J7461999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Limerick,Units 1 & 2.With ML20199G2371999-01-31031 January 1999 Rev 0 to NEDO-32645, Limerick Generating Station,Units 1 & 2 SRV Setpoint Tolerance Relaxation Licensing Rept ML20199L5301999-01-19019 January 1999 Special Rept:On 981214,seismic Monitor Was Declared Inoperable.Caused by Spectral Analyzer Not Running.Attempted to Reboot Sys & Then Sent Spectral Analyzer to Vendor for Analysis & Rework.Upgraded Sys Will Be Operable by 990331 B110078, Rev 1 to GE-NE-B1100786-01, Surveillance Specimen Program Evaluation for Limerick Generating Station,Unit 11998-12-31031 December 1998 Rev 1 to GE-NE-B1100786-01, Surveillance Specimen Program Evaluation for Limerick Generating Station,Unit 1 ML20205K0381998-12-31031 December 1998 PECO Energy 1998 Annual Rept. with ML20199F9611998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Limerick Generating Station.With ML20198C7151998-12-10010 December 1998 Rev 1 to COLR for LGS Unit 1,Reload 7,Cycle 8 ML20198A3871998-12-10010 December 1998 Safety Evaluation Supporting Licensee Response to GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power- Operated Gate Valves ML20206N4061998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Limerick Generating Station,Units 1 & 2.With ML20199E3281998-11-23023 November 1998 Rev 2 to PECO-COLR-L2R4, COLR for Lgs,Unit 2,Reload 4,Cycle 5 ML20195C9771998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Limerick Generating Station,Units 1 & 2.With ML20154H5691998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for Limerick Generating Station,Units 1 & 2.With ML20151X3511998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Limerick Generating Station Units 1 & 2.With ML20237F0291998-08-27027 August 1998 Special Suppl Rept:On 960425,one Loose Part Detection Sys (Lpds) Was Identified to Be Inoperable.Initially Reported on 960531.Caused by Loose Parts Detector Module.Repairs Performed & Intermittent Ground No Longer Present ML20237D1041998-08-17017 August 1998 Books 1 & 2 of LGS Unit 1 Summary Rept for 960301-980521 Periodic ISI Rept 7 ML20237A7761998-08-10010 August 1998 SER Accepting Licensee Response to NRC Bulleting 95-002, Unexpected Clogging of RHR Pump Strainer While Operating in Suppression Pool Cooling Mode ML20236X7641998-07-31031 July 1998 Rev 0 to SIR-98-079, Response to NRC RAI Re RPV Structural Integrity at Lgs,Units 1 & 2 ML20237B4711998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Limerick Generating Station,Units 1 & 2 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 ML20151Z4881998-06-30030 June 1998 GE-NE-B1100786-02, Surveillance Specimen Program Evaluation for Limerick Generating Station,Unit 2 ML20236P9781998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Limerick Generating Station,Units 1 & 2 ML20196K1801998-06-30030 June 1998 Annual 10CFR50.59 & Commitment Rev Rept for 970701-980630 for Lgs,Units 1 & 2. with ML20249B3501998-06-11011 June 1998 Rev 1 to PECO-COLR-L2R4, COLR for LGS Unit 2 Reload 4,Cycle 5 ML20249A5331998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Limerick Units 1 & 2 ML20247M7071998-05-14014 May 1998 Safety Evaluation Supporting Amend 128 to License NPF-39 ML20217Q5101998-05-0404 May 1998 Safety Evaluation Supporting Amend 127 to License NPF-39 ML20247H5071998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Limerick Generating Station ML20216F3601998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for Limerick Generating Station,Units 1 & 2 ML20217M0791998-03-31031 March 1998 Safety Evaluation Supporting Amends 125 & 89 to Licenses NPF-39 & NPF-85,respectively ML20217D5701998-03-20020 March 1998 Part 21 Rept 40 Re Governor Valve Stems Made of Inconel 718 Matl Which Caused Loss of Governor Control.Control Problems Have Been Traced to Valve Stems Mfg by Bw/Ip.Id of Carbon Spacer Should Be Increased to at Least .5005/.5010 ML20216F9471998-02-28028 February 1998 Monthly Operating Repts for Feb 1998 for Limerick Generating Station,Units 1 & 2 ML20216F3471998-02-28028 February 1998 Revised Monthly Operating Rept for Feb 1998 for Limerick Genrating Station,Unit 1 1999-09-30
[Table view] |
Text
_ _ _ _ _ _ _ _ _ _ _ _
10 CFR 50.73 l
PHILADELPHIA ELECTRIC COMPANY UMERICK GENERATING STATTON P. O. BOX 2300 SANATOGA, PA 19464-2300 ;
(215) 327-1200 EXT. 2000 J. DOERING. JR. May 5,1993
$7ja%8,,yg ym Docket No. 50-352 i License No. NPF-39 l
i U.S. Nuclear Regulatory Commission Attn: Document Control Desk ;
Washington, DC 20555 *
SUBJECT:
Licensee Event Report Limerick Generatina Station - Unit 1 ,
1 This LER reports an inadvertent Primary Containment and Reactor Vessel isolation Control System actuation, an Engineered Safety Feature, as a result of personnel error during performance of a Surveillance Test procedure.
Reference:
Docket No. 50-352 Report Number: 1-93-004 l Revision Number: 00 Evert Date: April 5, 1993 Report Date: May 5,1993 Facility: Limerick Generating Station P.O. Box 2300, Sanatoga, PA 19464-2300 This LER is being submitted pursuant to the requirements of 10 CFR 50.73(a)(2)(iv).
l Very truly yours, !
DCS:cah cc: T. T. Martin, Administrator, Region I, USNRC N. S. Perry, USNRC Senior Resident Inspector, LGS l
l 12H0Ei l
9305140076 930505 '
[ PDR ADOCK 05000352 S PDR 3 I
1
. . .- s. ~ . - - .-.. ._. ~ . - - ._ ._ . - _ _ . . ----
)- ,
NHCForm 3be U.S. NUCLEAR REGULATORY COMMisssON
' APPROVIO OMB NO.3160-01Da .
5 ""55: 8""
,' LICENSEE EVENT REPORT (LER) f 4
OOCKET NUMBER Cl P AG& 13e <
e F ACIUTV NAME 11D
~
Limerick Generating Station, Unit 1 ol51010lo1 3 l512 1 lorl 014 i
" " Primary Containment and Reactor Vessel Isolation Control System Actuation Resulting From Personnel Error during performance of a Surveillance Test Procedure, REPORT OATE n> cTnER e ACiufiEs wvotvto isi :
f EVENT OATE isi LER NUMsE R is, 4 MONT. CA. ,,AR .E.R -- =. e,w T. CA. .E.R . .C,mT . -... . -T UM. E R,,,
j 2
01 5l01010 I f I a
0l 0 0l5 0l5 9l3
~
0l4 0l5 93 9l3 0 l 0 l4 ois s ol0;0; ; ;
l TMt$ REPORT #1 $UsutTTED PUREUANT TO THE REQUIREMENTS OF 10 CFa g: #Cneca one er more e, no ,onomey# tits j OPE R AT WG
- MODE m } 70 402ib) 20 40stel X 50.73teK2 Heel 73.711bl a
$0.73tel(2Het 73.71(c) l E st 20 405laH1Ha SS.36( H1) f101 1 g 0;O 20 esi.inHa _
so m H2 so.73,,iaH*
_ gag 7,yg j 20 406teH1Het $0.73is)GHil ,
50.731eH2HeWHA) J66Al i
' 50.733elt2HvGHal l 20 40$ielt1H6el . - 60.73EoH2HND
.i s
20,4354eH1Het 50.736elGHeib 50.73(alGHal LICENEEE CONTA. T FOR THIS LE R 6121 SAMg TELEPHONE NUMBER
" ARE A CODE
,y f I I I i i i I I I
' l COMPLETE ONE LINE FOR E ACM COMPONENT F AILURE OE'SCRISED SN THt$ REPORT (138 CAUEE $v5 TEM COMPObE NT "h C.
O PR CAU$E $v$7E M COMPONENT M - R ATa pp { h[
~' '
- I I I I I I I i I t I I i l
. 1 1 1 I I I I I '
MONTH . Oav VEAR
$UPPLEMENTAL REPORT EXPECTED (14)
s!Is"MisIiON j ] vEs m m . <mer,0 su, mss,0N OAm T] NO l l l ,
Assu AC2 ,t.m.,,,,u0 .
....,,..,,,,,,.,,,.,-..,,,n.i j
On April 5, 1993, at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, while performing Unit 1 Surveillance Test (ST) 1 procedure ST-2-026-624-1, "NSSSS-Refueling Area Ventilation Exhaust Duct Radiation-High; Division II A, Channel C Functional lest (RISH-26-1K610C) " a
, station Instrumentation and Controls (l&C) technicians inadvertently caused a Unit 1 'A' channel Refuel Floor high radiation isolation signal. The isolation ,
signal resulted in automatic actuation of portions of the Primary Containment I
~ and Reactor Vessel Isolation Control System (PCRVICS), an Engineered Safety Feature (ESF). The isolation signal resulted in the automatic closure of
- Primary Containment H2/02 Combustible Gas Analyzer' Sample Line Isolation Valves l SV-57-133, 183, and 191. Main Control Room (MCR) personnel verified all j appropriate isolations. The actual and potential consequences of this event were minimal and there was no release of radioactive material to the environment as a result of this event. The cause of this event was personnel error in that l an I&C technician manipulated incorrect equipment during performance of the ST procedure. The contributing components of this personnel error included less than adequate self-checking and failure to utilize repeat back during procedure performance. The involved technician was counseled on the importance of self-checking and proper communications. All I&C technitlans are currently being given a newly implemented On the Job Training module on self-check and self- ;
verification. I&C supervision hcve increased field observations of technicians '
i to ensure that the principles of self-checking are being implemented.
a#RC fore 366
, 19 833
=- - ._ _. . ._
)
=
a wxe e . seer u.s. auctran stacutATsar commission !
LICENSEE EVENT REPORT (LERI TEXT CONTINUATION Aernovto ous wo. 2 iso-oio.
'.**** smats ames
,ac.urv ===< m oocm numsta m can muussa m eroa m -
vraa - R' W. ' Z'1",0 ;
Limerick Generating Station, Unit 1 o l5 jo [o l0 l3 l5l2 9l3 -
0 l0 l 4 -
0l0 0 l2 OF 0 l4 ,
,w,.=.--~-
Unit Conditions Prior to the Event:
Unit I was in-0pe' rational Condition 1 (Power Operation) at 100% power at the '
time of this event.
- i There were no structures, systems, or components out of service that contributed i to this event. .
Description of the Event:
On April 5, 1993, at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, while performing Unit 1 Surveillance Test (ST) procedure ST-2-026-624-2, "NSSSS-Refueling Area Ventilation Exhaust Duct Radiation-High; Division II A, Channel C Functional Test (RISH-26-1K610C)," a ;
station Instrumentation and Controls (I&C) technician inadvertently caused a Unit 1 'A' channel Refuel Floor high radiation isolation signal. The isolation '
signal resulted in an automatic actuation of portions of the Primary Containment ,
and Reactor Vessel Isolation Control System (PCRVICS), an Engineered Safety i Feature (ESF).
"e. isolation signal resulted in the automatic closure of Primary Containment i H2/02 Combustible Gas Analyzer (CGA) (EIIS:BB) Sample Line Isolation Valves SV- '57-133, 183, and 191. This caused the CGA, which monitors the primary containment atmosphere, to isolate and recirculate its gas flows. '
i Main Control Room (MCR) personnel verified all appropriate isolations in ,
accordance with General Plant (GP) procedure GP-8, " Primary And Secondary Containment Isolation Verification and Reset." The 1&C technician involved +
notified the MCR personnel of the nature of the inadvertent isolations. After {
verifying that no high radiation condition existed, MCR personnel reset the isolation signal in accordance with procedure GP-8 at 0916 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.48538e-4 months <br />. ,
A four hour notification to the NRC was made in accordance with the requirements of 10CFR50.72(a)(2)(ii) at 1132 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.30726e-4 months <br /> on April 5, 1993, since this event ;
resulted in the automatic actuation of an ESF. This written report is being- l submitted in accordance with 10CFR50.73(a)(2)(iv).
)
Analysis of the Event:
The actual and potential consequences of this event were minimal and there was no release of radioactive material to the environment as a result of this event.
All systems responded as designed in response to the inadvertent high radiation isolation signal. The redundant CGA was operable and available to sample from either the drywell or the suppression pool air space during this event. There were no immediate operator actions required during this event to ensure continued safe operation of the plant and plant equipment.
Immediate and follow-up actions for this type of event, inadvertent Refuel floor !
high radiation isolation, are provided in procedure GP-8. Licensed MCR goo. a .
I
- ___ _ - ~ .
_--___m _ _- --__..._-m._ m . _.m.. . .-
t hnC .sesm*J66. U.S. NUCLEAR REGULATORY CDMMISEloN F P LICENSEE EVENT REPORT (LER) TEXT CONTINUATION .eenovac ous =o. siso-oio.-
tar,ats soies
[
l
. .C,u r . .. m - - . . = u.... .... m :
ma "t .Wt' ' CJ,T: j Limerick Generating Station, Unit 1 olslojojol3l5l2 9l3 -
0l0l4 -
0 l0 0 l3 or 0 l4 r_n..,_,... n e a.- - ,n m operators receive requalification training to review and practice responses to {
simulated plant transients of this type. This training reinforces immediate i operator actions,~ minimizing the time that systems are isolated, and reducing j the impact on the plant. Therefore, as a result of this adequate procedural ;
guidance, training, prompt operator actions, and operable redundant equipment, t the actual and potential consequences of this type of event were minimal. .
Cause of the Event:
The cause of this event was personnel error in that an I&C technician !
manipulated incorrect equipment during performance of the ST procedure. The !
involved technicians were planning to perform tests cn both Division I and Division II equipment on April 5, 1993. Normal practice is to perform Division {
I testing first. In this instance, however, while the I&C technician in the Auxiliary Equipment Room (AER) was preparing to perform Division I testing, the '
I&C technician in the MCR directed him to perform Division 11 testing first due ,
to the availability of operations support personnel needed to support the ;
Division 11 task. The technician in the AER acknowledged and understood the !
direction'but proceeded to implement the test on Division I equipment. This !
caused the Division I isolation signal and resultant ESF actuations. The !
contributing components of this personnel error included less than adequate i self-checking and failure to utilize repeat back during procedure performance. l An interview was conducted on April 28, 1993, with 1&C personnel involved in j recent personnel error events, to determine if any additional causal factors !
could be identified. From the interview we determined that in general the !
mechanics of self-checking were not clearly defined for the technicians. During !
the interview, the technician involved recalled having several personal events l which may have contributed to his decreased attentiveness. Interaction between i the technician and supervision did not serve to identify the potential impact of l these events. Additionally the interview revealed that On-the-Job Training '
(0JT) during procedure performance may have resulted in unnecessary distractions <
for the technicians performing the work.
Corrective Actions: i The involved technician was counseled on the importance of self-checking and proper communication. All l&C technicians are currently being given a newly implemented OJT module on self-checking and self-verification. This module reinforces the importance and mechanics of self-checking to reduce the likelihood of these types of events occurring. All 1&C technicians are expected to complete the OJT module by June 30, 1993. Additionally, I&C Supervision will reevaluate the OJT process to ensure minimal impact on the work being performed and observed.
A memorandum will be issued by May 31, 1993, to all first line supervisors at Limerick emphasizing the lessons learned from this event and the need for increased sensitivity to the potential performance impact of external personal i l
l i
se romas mess
i I
. 1 are se..Tasa u s. m ucitaa statutaroar commission
"" Aremovto ous no. sin-oio. ' ;
- LICENSEE EVENT REPORT (LER) TEXT CONTINUATION
<xeines armes l , ]
e m ury .me m oocan avuesa m tem numera e eace ai i
'5'a -
"Rit!'.'. ' - TJ.*J l Limerick Generating Station, Unit 1 o l5 }o l0 l0 l3 l5l2 9l3 -
o jo l .4 _
o (o 0 l4 or o l4 rext in - . . .u - - unc r ans.wnn ;
i distractions. Additionally, I&C Supervision have increased field observations of technicians to ensure that the principles of self-checking are being :
implemented. -
Previous Similar Occurrences:
i Unit 1 LERs 1-92-017,1-91-020, and 1-89-048 reported ESF actuations'due to -
personnel error involving failure to perform self-check. Corrective actions for :
these events included individual counseling, all hands meetings and enhanced i training. The enhanced training was in the process of being implemented at the ,
time of this event and therefore was not able to prevent this occurrence.
1 e
t i
l o
,oau n
. .-. . - .-