Pages that link to "05000251/LER-2008-001, Manual Reactor Trip Due to High Level in the 4A Steam Generator"

The following pages link to 05000251/LER-2008-001, Manual Reactor Trip Due to High Level in the 4A Steam Generator:

Displayed 9 items.

• 05000251/LER-2008-001 (redirect page) ‎ (← links)
  • 05000251/LER-2015-001, Automatic Auxiliary Feedwater System Actuation during a Planned Reactor Trip ‎ (← links)
  • 05000361/LER-2008-003 ‎ (← links)
  • 05000270/LER-2008-002 ‎ (← links)
  • 05000251/LER-2001-002 ‎ (← links)
  • 05000251/LER-2001-001 ‎ (← links)
  • 05000251/LER-1982-008, Forwards LER 82-008/03L-0 ‎ (← links)
  • 05000251/LER-1982-007, Forwards LER 82-007/01T-0 ‎ (← links)
  • 05000251/LER-1982-002, Forwards LER 82-002/01T-0 ‎ (← links)
  • 05000251/LER-1982-006, Forwards LER 82-006/01T-0 ‎ (← links)
  • 05000251/LER-1982-013, Forwards LER 82-013/03L-0 ‎ (← links)
  • 05000251/LER-1982-011, Forwards LER 82-011/03L-0 ‎ (← links)
  • 05000251/LER-1981-014, Forwards LER 81-014/02T-0 ‎ (← links)
  • 05000251/LER-1982-010, Forwards LER 82-010/03L-0 ‎ (← links)
  • 05000251/LER-1982-014, Forwards LER 82-014/03L-0 ‎ (← links)
  • 05000251/LER-1983-003, Forwards LER 83-003/01T-0 ‎ (← links)
  • 05000251/LER-1983-001, Forwards LER 83-001/01T-0 ‎ (← links)
  • 05000251/LER-1982-009, Forwards LER 82-009/03L-0 ‎ (← links)
  • 05000251/LER-1989-002, :on 890412,Train a Safeguards Actuation Occurred After Operator Installed Fuses.Caused by Inadequate Administrative Controls.Instruction to Use Procedure Added to Std Clearances ‎ (← links)
  • 05000251/LER-2020-001, Automatic Reactor Trip Caused by Main Generator Lockout Due to Exciter Fault ‎ (← links)
  • 05000251/LER-1987-022-01, :on 870914,all Three Boric Acid Storage Tanks Declared Out of Svc.Caused by Misinterpretation of Tech Spec 3.6.Adequate Tank Level & Proper Pump Lineup Verified & Clarification Ltr Issued ‎ (← links)
  • 05000251/LER-1986-020, :on 860926,blowdown Isolation Valves Failed Closed & Not Isolated within 4 H.Caused by Personnel Error & Water Leaking from Feedwater Valve.Personnel Counseled. Failed Valves Repaired or Replaced.Leaking Valve Repaired ‎ (← links)
  • 05000251/LER-1986-018-01, :860824,auxiliary Feedwater Flow Control Valve Failed to Open Fully.Caused by Pressure Conversion Module Terminal W/Corrosion That Resulted in High Electrical Resistance.Terminal Cleaned ‎ (← links)
  • 05000251/LER-1986-014, :on 860805,while Tests 4-OSP-089 & TOP-233 Being Performed,Subcritical Reactor Trip Occurred.Caused by Personnel Oversight in Preparing TOP-233 to Ensure at Power Trip Signals Clear.Procedure Reviewed ‎ (← links)
  • 05000251/LER-1986-023-01, :on 861025,operators Noted Loss of Ready to Start Light & Simultaneous Annunciation of Emergency Diesel Generator B Trouble Alarm.Caused by Low Lube Oil Temp Causing Shorting of Above Wire to Ground ‎ (← links)
  • 05000251/LER-1986-024-01, :on 861027,post-maint Testing of Valves Missed. Caused by Personnel Error.Valves Satisfactorily Tested on 861027,Training Brief 185 Issued,Procedures Revised & Personnel Counseled ‎ (← links)
  • 05000251/LER-1986-012-01, :on 860711,during Cold Shutdown,Process Radiation Monitor R-11 Failed High,Resulting in Control Room/Containment Ventilation Isolation Logic.Caused by Zener Diode Failure.Diode Replaced ‎ (← links)
  • 05000251/LER-1987-004-01, :on 870205,intake Cooling Water Pumps 4C & 4B Declared Out of Svc.Caused by Repairs to Discharge Check Valve Air Cylinder & Failure of Pump Shaft Coupling.Repairs Completed & Couplings Replaced ‎ (← links)
  • 05000251/LER-1987-003-01, :on 870127,process Radiation Monitor (PRM) R-12 Spiked High.Caused by Inability of Drawers to Filter Out Electrical Transients.Prm R-11 & R-12 Reset.Cause of Transients Evaluated ‎ (← links)
  • 05000251/LER-1986-026-01, :on 861114,control Room Ventilation & Containment Vent Isolations Occurred Due to Failed Process Radiation Monitor R-11.Caused by Failed Resistor & Defective Meter in Monitor.Resistor & Meter Replaced ‎ (← links)
  • 05000251/LER-1986-025-01, :on 861110,reactor Trip Occurred When Reactor Protection Logic of lo-lo Steam Generator Level on Two Out of Three Channels on Steam Generator 4C Was Completed.Caused by Failed Solenoid Coil ‎ (← links)
  • 05000251/LER-1986-021-02, :on 860926 & 1006,blowdown Isolation Valves Failed Closed.Caused by Personnel Error.Personnel Counseled to Exercise Greater Caution in Ensuring Compliance W/Tech Specs & Valves Repaired or Replaced ‎ (← links)
  • 05000251/LER-1986-021-01, :on 860916,unit Shut Down Due to Malfunction in Rod Position Indication (RPI) Sys.Caused by Failed Line Voltage Regulator in RPI Power Sys.Regulator Replaced & RPI Inverter Output Checked ‎ (← links)
  • 05000251/LER-1986-017-01, :on 860809,auxiliary Feedwater Flow Initiated Following Testing of Automatic Feedwater Sys.Caused by Personnel Error.Operator Counseled & Procedure AP-103.16 Re Technical Advisor Duties Revised ‎ (← links)
  • 05000251/LER-1986-019-01, :on 860906,reactor Tripped.Caused by Short in Light Socket for Feedwater Isolation Circuit 4C in Safeguards Rack 44 During Maint.Light Socket Replaced & Satisfactorily Tested to Preclude Recurrence ‎ (← links)
  • 05000251/LER-1987-002-01, :on 870112,component Cooling Water Pump 4B (Ccwp) Header Low Pressure Alarmed & Auto Started.Cause Unknown.Header Low Pressure Sensing Switch Checked Out & Found to Be Operating Properly ‎ (← links)
  • 05000251/LER-1980-007-01, /01T-2:on 800507,disc Stud Nut Discovered Missing from Main Steam Check Valve 4A.Caused by Failure of Associated Locking Device.Disc Studs Replaced & Improved Locking Device Installed ‎ (← links)
  • 05000251/LER-1986-015-01, :on 860820 & 21,Tech Spec 3.0.1 Entered Due to Valve MOV-4-1404 Failing to Close & Auxiliary Feedwater Declared Out of Svc,Respectively.Valve Failed Due to Open Contact.Wire Bundle Moved ‎ (← links)
  • 05000251/LER-1986-016-01, :on 860823,manual Reactor Trip Initiated Following Drop of Group 2 Rods in Control Banks B & D & Shutdown Bank B Group 2 Rods.Caused by PS-1 Vdc Supply Failure W/Redundant Supply Out of Svc ‎ (← links)
  • 05000251/LER-1987-001-01, :on 870106,reactor Tripped During Operating Surveillance Procedure 4-OSP-059.4.Caused by Spiking on Channel III Over Temp Delta Temp Due to Failure of Isolation Amplifier.Isolation Amplifier Replaced ‎ (← links)
  • 05000251/LER-1987-004, :on 870205,intake Cooling Water Pumps 4B & 4C Declared Out of Svc.Caused by Failed Pump Shaft Coupling on Pump 4B & Lengthy Maint Time on Pump 4C Discharge Check Valve Air Cylinder ‎ (← links)
  • 05000251/LER-1987-005-01, :on 870212,process Radiation Monitor Tripped Causing Containment & Control Room Ventilation Isolation. Caused by Failed Transistor & Resistor.Transistor & Resistor Replaced ‎ (← links)
  • 05000251/LER-1986-030-01, :on 861219,process Radiation Monitor R-12 Spiked,Causing Control Room Ventilation & Containment Vent Isolation.Caused by Electrical Transient While Meggering R-15 Cable.Monitor R-12 Reset ‎ (← links)
  • 05000251/LER-1986-028-01, :on 861210,auxiliary Feedwater Sys (AFW) Pump a Started Inadvertently During Maint on AFW Pump B.Caused by Personnel Error.Personnel Counseled ‎ (← links)
  • 05000251/LER-1986-029-01, :on 861212,radioactive Particulate Containment Radiation Monitor Spiked High,Actuating Containment & Control Room Ventilation Isolation Logic.Caused by Two Broken Solder Joints & Failed Resistor ‎ (← links)
  • 05000251/LER-1986-027-01, :on 861205,process Radiation Monitor Failed High,Actuating Containment & Control Room Ventilation Isolation Logic.Caused by Broken Solder Joint,Defective Detector & Failed Monitor.Parts Replaced ‎ (← links)
  • 05000251/LER-1986-020-01, Forwards LER 86-020-01.Rept Submitted as LER 86-21 on 861027 W/Ltr L-86-442.Event Should Have Been Reported as LER 86-20. Rev Corrects Numbering Discrepancy & Coding Errors ‎ (← links)
  • 05000251/LER-1986-013-01, :on 860722 & 24,while Performing Maint on Safeguard Relays,Phase a Containment Isolation Actuated. Caused by Inadvertent Relay Actuation.Actuation Signal Reset & Valves Reopened ‎ (← links)
  • 05000251/LER-1987-006-01, :on 870224,standby Primary Water Makeup Pump Running Alarm Actuated Indicating That Discharge Pressure Decreased.Caused by Suction Check Valve Malfunction.Visual Insp of Floating Rubber Diaphragm Performed ‎ (← links)
  • 05000251/LER-1986-022-01, :on 860908,Phase a Containment Isolation of Train B Actuated.Caused by Personnel Error & Wire/Bundle Relay Interference During Insp.Technicians Counseled & Request for Technical Assistance Written ‎ (← links)
  • 05000251/LER-1986-008-01, :on 860329,intake Cooling Water Pump 4A Started.Caused by Const Activity in Area.Const Workers Instructed to Use Caution ‎ (← links)
  • 05000251/LER-1986-007-01, :on 860326,automatic Start of Emergency Diesel Generator B Occurred.Caused by Inadvertent Jarring of Overcurrent Relay Due to Const Activity Nearby.Event Discussed W/Const Crew ‎ (← links)
  • 05000251/LER-1986-011-01, :on 860613,process Radiation Monitor R-11 Spiked High,Actuating Containment & Control Room Ventilation Isolation Logic.Caused by Keying of Fm Radio.Monitor Will Be Repaired During Present Refueling Outage ‎ (← links)
  • 05000251/LER-1986-018, :on 860824,auxiliary Feedwater Flow Control Valve CV-4-2831 Failed to Open Fully.Caused by Corroded Terminal Due to Water in Pressure Conversion Module.Terminal Cleaned ‎ (← links)
  • 05000251/LER-1986-010-01, :on 860425,during Performance of Periodic Test Load on 4A 4-kV Bus,Breaker 4AA20 Failed to Close.Caused by Breaker Position Switch 52HH Not Being Actuated.Position Switch Replaced W/Redesigned Actuator & Guide ‎ (← links)
  • 05000251/LER-1986-005-01, :on 860206,Phase a Containment Isolation Activated.Caused by Inadvertent Physical Disturbance of Safeguards Relay by Const Personnel.Containment Isolation Reset ‎ (← links)
  • 05000251/LER-1986-002, :on 860104,while Operating at 100% Power, Turbine Runback Occurred & Control Bank C Rod Cluster M-6 Dropped Into Core.Caused by Faulty Stationary Gripper Coil. Coil Replaced ‎ (← links)
  • 05000251/LER-1986-001, :on 860101,auxiliary Feedwater Pumps a & C Started Due to Valve 4-10-320 Not Being Seated Properly. Caused by Broken Guide Stud on Valve.Valve Repaired in Accordance W/Nrc Disposition & Tested ‎ (← links)
  • 05000251/LER-1986-004-01, :on 860126,Phase a Containment Isolation Actuated.Caused by Const Activity in Area Resulting in Inadvertent Jarring of Safeguards Relay.Phase a Containment Isolation Signal Reset ‎ (← links)
  • 05000251/LER-1986-006-02, :on 860315,containment & Control Room Ventilation Sys Isolated Due to Opening of Breaker 4P08-20 Causing Loss of Process Radiation Monitor Rack.No Cause Identified.Procedure Will Be Revised ‎ (← links)
  • 05000251/LER-1986-003-02, :on 860120,boron Concentration Below Tech Spec Limits.Caused by Misinterpretation of Tech Spec Requirements During 10-day Shutdown Following 860117 Distension of Reactor Vessel Head Bolts.Procedures Revised ‎ (← links)
  • 05000251/LER-1985-026-01, :on 851224,480-volt Power Supply Breaker to Backup Group 4A Pressurizer Heaters Discovered to Have No Light Indication.Caused by Backing Off Action by Arcing Contacts.Breaker Manually Tripped ‎ (← links)
  • 05000251/LER-1985-025-01, :on 851123,reactor Trip Occurred at Hot Standby Conditions.Caused by Intermediate Range Detectors Overcompensated Due to Voltage Setpoint Drift.Compensation Voltage Adjusted ‎ (← links)
  • 05000251/LER-1985-024-01, :on 851102,automatic Initiation of Standby Component Cooling Water Pump 4A Occurred.Caused by Maint & post-maint Testing Performed on auto-start Circuitry PC-611. Auto-start Circuitry Returned to Svc ‎ (← links)
  • 05000251/LER-1985-023-01, :on 850824,discovered That Containment Isolation Valve CV-4-956A Not Tested on Quarterly Cycle,Per Tech Spec 3.3.3.Caused by Failure to Note Previous Testing Problems on Valve Clearance.Valve Tested ‎ (← links)
  • 05000251/LER-1985-022-01, :on 851016,4A 4160-volt Breaker 4AA8 Tripped, Deenergizing Load Ctr.Cause of Trip Unknown.Breaker Replaced ‎ (← links)
  • 05000251/LER-1985-021-01, :on 850820,turbine Runback & Reactor Trip Occurred Due to Reactor Protection Sys Actuation.Caused by Rod Drops Resulting from Electrical Malfunctions.Gripper Coil on CRD Mechanism Replaced ‎ (← links)
  • 05000251/LER-1985-020-01, :on 850626,agastat in Closing Circuitry for Bypass Valve Failed Causing Closure Due to Interlock Between Valves CV-4-6275C & CV-4-6275C-1.On 850808,steam Generator 4C Blowdown Isolation Valve Inoperable ‎ (← links)
  • 05000251/LER-1985-016-01, :on 850618,motor Control Ctr 4A Taken Out of Svc,Requiring Cooldown of Unit.Caused by out-of-adjustment Breaker Trip Latch on Vital to Nonvital Tie Breaker 40535 Associated w/4A 480-volt Ac Motor Control Ctr ‎ (← links)
  • 05000251/LER-1985-018, :on 850623,critical Heat Tracing Circuits 8A & 8B Declared Out of Svc.Caused by Heat Tracing Circuit 9 Inadvertently Coming in Contact W/Heat Tracing Circuit 8. Circuits 8A & 8B Repaired & Returned to Svc ‎ (← links)
  • 05000251/LER-1985-013-01, :on 850606,reactor Tripped as Result of Turbine Trip.Caused by Inverter Trip Originating in Input Filters on Supply Side of Power Fuses.Fuse on Inverter & Input Filters Replaced.Inverters Replaced W/New Model ‎ (← links)
  • 05000251/LER-1985-014-01, :on 850608,containment & Control Room Ventilation Isolation Occurred When Pressurizer Relief Tank Drained.Caused by Leakage from Pressure Control Valve.Block Valve Closed.Faulty Valve Repaired ‎ (← links)
  • 05000251/LER-1985-009-01, :on 850425,emergency Diesel Generator a Taken Out of Svc Coincident W/High Head Safety Injection Pump. Caused by Personnel Error.Generator a Returned to Svc, Personnel Counseled & Procedures Revised ‎ (← links)
  • 05000251/LER-1985-012-01, :on 850530,reactor Trip Occurred Due to Loss of Power from as Inverter to 120-volt Ac Vital Instrument Bus for Panel 4P07.Caused by Blown Fuse on Spare as Inverter. Power Restored & Inverter Successfully Tested ‎ (← links)
  • 05000251/LER-1985-015, :on 850610,while Emergency Diesel Generator B Out of Svc,Generator a Declared Out of Svc.Caused by Personnel Allowing Water Into Motor Control Ctr Where Bus Shorted Out.Generator Cleaned & Reenergized ‎ (← links)
  • 05000251/LER-1985-008-01, :on 850411,small Leak Discovered at Fitting on Test Connection Between Containment & Containment Isolation Valve.Caused by Test Connection Leakage & Malfunction of Valve CV-4-951 ‎ (← links)
  • 05000251/LER-1985-011-01, :on 850517,reactor Trip Occurred When off-site Power Lost Due to Multiple Faults on High Voltage Power Sys. Caused by Multiple Intense Brush Fires.Natural Circulation Cooling Established ‎ (← links)
  • 05000251/LER-1985-010-01, :on 850515,turbine & Reactor Trip Occurred. Caused by Actuation of ESF Relay Inadvertently Bumped by Const Worker While Performing App R Mods.Const Halted. Post-trip Review Found No Abnormal Conditions ‎ (← links)
  • 05000251/LER-1985-005, :on 850207,spurious Safety Injection Signal Generated in ESF Sys W/No Resultant Safety Injection Flow. Caused by Blown Fuse on Flow Comparator of Steam Generator B Coincident W/Electrical Spike.Fuse Replaced ‎ (← links)
  • 05000251/LER-1985-006-01, :on 850207,auxiliary Feedwater Sys Actuated Automatically.Caused by Incorrect Setting of Relay on 4,160- Volt Bus C.Auxiliary Feedwater Pumps Reset & Affected Relay Rewired ‎ (← links)
  • 05000251/LER-1985-004-01, :on 850207,high Voltage Flashover Occurred on Insulating Support of 240-kV Circuit Switcher.Caused by Gradual Buildup of Dirt & Salt Deposits on Insulating Supports.Electrical Insulators Cleaned ‎ (← links)
  • 05000251/LER-1984-027-01, :on 841130,RHR Sys Flow Interrupted for 4 Minutes.Caused by Closure of Isolation Valve MOV-4-751 in RHR Pump Suction Line Due to Malfunction in Pressure Controller PC-405B.RHR Pump B Restarted ‎ (← links)
  • 05000251/LER-1985-003-01, :on 850206,reactor Tripped Due to Reactor Protection Logic of Steam Flow Greater than Feed Flow.Caused by Steam Flow/Feed Mismatch Alarm & Decrease in Steam Generator Level ‎ (← links)
  • 05000251/LER-1984-026-01, :on 841124,automatic Initiation of Auxiliary Feedwater Sys Occurred.Caused by Personnel Oversight by Not Maintaining Adequate Level in Steam Generator B.Auxiliary Feedwater Pumps Stopped & Secured ‎ (← links)
  • 05000251/LER-1984-025-01, :on 841124,reactor Trip Occurred.Caused by Ground in One Stab Connector of Reactor Coolant Pump 4a Breaker.Unit Brought to Refueling Shutdown Condition to Deenergized 4a 4-kV Bus for Insp & Repair ‎ (← links)
  • 05000251/LER-1984-024-01, :on 840907,temp Average & Delta Temp Summator Module NM412D Found Defective.Mgt Determined Problem Reportable as Generic Defect on 841015.Module Replaced & Engineering Staff Evaluating Module Upgrade ‎ (← links)
  • 05000251/LER-1984-020-01, :on 840914,redundant Containment Isolation Valve V-4-204 on Svc Air Header Found Open.Cause Unstated. Valve Closed & Lock for Valve Relocated to Valve Handle ‎ (← links)
  • 05000251/LER-1985-001, :on 850102,containment Isolation Valve SV-2819 Failed to Close at 100% Power Upon Receiving Containment Ventilation Isolation Signal.Caused by Dirt Buildup on Contacts in Lockout Relay.Contacts Cycled ‎ (← links)
  • 05000251/LER-1985-021, :on 840920,turbine Runback & Reactor Trip Occurred Upon Nis Rod Drop Signal.Caused by Failure of Inverter 4A to Provide Power to Vital 120-volt Instrument Bus,Panel 4P07,due to Blown Fuse ‎ (← links)
  • 05000251/LER-1985-007, :on 850218,containment Spray Pump Power 4A Supply Breaker Inoperable.Caused by Closing Spring Charging Motor Being Off During Test,Resulting in Closing Springs Discharging.Charging Power Restored ‎ (← links)
  • 05000251/LER-1984-023-01, :on 841016,reactor Trip Occurred.Caused by Detector on Nis N-32 Channel Failing & Generating High Level Signal.Nis Channel N-32 Taken Out of Svc & Detector Replaced ‎ (← links)
  • 05000251/LER-1984-022-01, :on 841009,during Heat Up from Cold to Hot Shutdown,Reactor Trip Occurred.Caused by Blown Fuse Supplying Instrument Power to Panel 4P07,which Caused Instrumentation Bistables to Deenergize ‎ (← links)
  • 05000251/LER-1985-002, :on 850129,emergency Diesel Generator a Out of Svc,Leaving Vital Buses 3A & 4A W/O Access to on-site Emergency Power.Caused by Short in Diesel Local Panel Light Socket ‎ (← links)
  • 05000251/LER-1984-017-01, :on 840807,Unit 4 Experienced Reactor Trip Coincident W/Loss of Unit 3 Startup Transformer.Caused by Incorrect Switching Order ‎ (← links)
  • 05000251/LER-1984-016-01, :on 840624,auxiliary Feedwater Sys Manually Actuated.Caused by Incorrect Hotwell Reject Regulator LCV-1500 Setup.Regulator Setup Corrected ‎ (← links)
  • 05000251/LER-1984-015-01, :on 840716,at Cold Shutdown,High Head Safety Injection Pump 4A Experienced Unexpected Start.Caused by Const Personnel Inadvertently Striking Local Control Switch on Breaker Cubicle 4A ‎ (← links)
  • 05000251/LER-1984-014-01, :on 840626,reactor Tripped from Hot Shutdown Conditions While Unit Subcritical for Practice Startups. Caused by Failure of Source Range Detector N-32.Detector Replaced ‎ (← links)
  • 05000251/LER-1984-013-01, :on 840624,automatic Initiation of Auxiliary Feedwater Occurred.Caused by Steam Generator Feedwater Pump 4B Trip Due to Inadequate Suction Pressure.Unit Stabilized & Auxiliary Feedwater Secured & Reset ‎ (← links)
  • 05000251/LER-1984-019-01, :on 840901,daily Calibr of Nuclear Power Range Not Performed.Caused by Operator Oversight.Listed Corrective Actions Taken ‎ (← links)
  • 05000251/LER-1984-018-01, :on 840829,limiting Condition for Operation for Intake Cooling Water Head 4B Exceeded.Caused by Personnel Error.Strainer Pressurized & Checked for Leakage,Clearance Order Released & Discussions Held W/Personnel ‎ (← links)
  • 05000251/LER-1984-009-01, :on 840527,28 & 30,low Discharge Flow Observed from Reactor Coolant Drain Tank Pumps.Caused by Damaged O-rings in Stem Guide to Valve Actuator.Damaged Diaphragms Replaced & Valve Stroke Adjusted ‎ (← links)
  • 05000251/LER-1984-008-01, :on 840601,reactor Trip Occurred.Caused by Personnel Error Resulting in Reactor Power Reaching 10% W/ Turbine in Tripped Condition.Equipment Functioned as Designed on Initiation of ESF Actuation Signal ‎ (← links)
  • 05000251/LER-1984-007-01, :on 840509,during Scheduled Refueling Outage, Three 480-volt Load Ctr Feeder Breakers Tripped.Caused by Procedural Deficiency.Power Restored to Three 480-volt Load Ctrs & Procedure Revised ‎ (← links)
  • 05000251/LER-1984-006-01, :on 840505,during Scheduled Refueling Outage, Actuation of Bus Stripping Relays Occurred on 4 Kv Bus. Caused by Personnel Accidentally Jarring or Shorting Electrical Auxiliary Contact Pair ‎ (← links)
  • 05000251/LER-1976-001-03, /03L:on 760130,channel 2 Overtemp delta-T Reactor Trip Setpoint Exceeded Tech Spec Limit by One Degree.Caused by Failure of Two Filter Capacitors in Signal Summator. Capacitors Replaced ‎ (← links)
  • 05000251/LER-1976-002-01, /01T:on 760214,water Level in Refueling Water Storage Tank 1% Lower than Tech Spec Requirement.Caused by Poor Calibr Ability of Wide Range Indicator Gage.Narrow Range Gage Will Be Installed as Backup ‎ (← links)
  • 05000251/LER-1976-007-01, /01T:on 761002,diesel Generator a Engine Cooling Water Tank Level Found Low.Caused by Sample Valve Not Being Fully Closed After 761001 Water Sample.Valve Closed & Water Added ‎ (← links)
  • 05000251/LER-1976-003-01, /01T:on 760517,tube Support Plate Section of Steam Generator 4C Discovered to Be Cracked.Cause Under Investigation.Manufacturer Evaluating Occurence ‎ (← links)
  • 05000251/LER-1976-004-01, /01T:on 760611,boron Concentration of Injection Tank & Two of Three Storage Tanks Below 20,000 Ppm Limit. Caused by in-leakage from Reactor Water Storage.Shutdown Initiated ‎ (← links)
  • 05000251/LER-1976-005-01, /01T:on 760612,boron Concentration of Boron Injection Tank & B Boric Acid Storage Tank Below 20,000 Ppm.Caused by in-leakage from Refueling Water Storage Tank. Shutdown Initiated ‎ (← links)
  • 05000251/LER-1976-006-03, /03L:on 760726,generator 4 Tripped by Lockout Action.Caused by Switch Not Making Proper Contact Preventing Breaker from Closing.Breaker Lowered & Raised to Establish Contact ‎ (← links)
  • 05000251/LER-1984-012-01, :on 840611,moderator Temp Coefficient Tech Spec Exceeded.Caused by Failure to Consider Changes in Parameters Affecting Fulfillment of Tech Spec Requirements.Reactor Power Reduced ‎ (← links)
  • 05000251/LER-1984-011-01, :on 840610,turbine Runback to 510 MW Occurred. Caused by Electrical Transient in Static Inverter 4A,causing Loss of Power to Vital Panel & Instrument Channel.Unit Stabilized & Standby Inverter Activated ‎ (← links)
  • 05000251/LER-1984-010-01, :on 840604,steam Generator Feedwater Pump 4A Tripped Due to Low Suction Pressure.Caused by Opening of Reactor Trip Breaker A.Reactor Trip Breaker a Replaced ‎ (← links)
  • 05000251/LER-1984-004-02, :on 840307,while Purging,Spurious Signal to Process Radiation Monitor R-11 Actuated Containment & Control Room Ventilation Sys Logic,Closing Purge Valve & Placing Ventilation Sys in Recirculation Mode ‎ (← links)
  • 05000251/LER-1984-002-02, :on 840212,reactor Trip Occurred Due to Steam Flow Greater than Feed Flow Coincident.Caused by High Steam Flow Reading on Steam Generator 4A.Calibr Check Performed ‎ (← links)
  • 05000251/LER-1984-001-02, :on 840212,reactor Tripped.Caused by Electrical synchronism-check Relay Malfunction.Design Reviewed & Automatic Turbine Governor Runback Logic Circuitry Tested Satisfactorily ‎ (← links)
  • 05000251/LER-1983-015-03, /03L-0:on 830913,local Leak Rate Test on Containment Personnel Hatch Airlock Revealed Leakage in Excess of Tech Specs.Caused by Equalizing Vent Valve on Inner Door Not Fully Closed.Valve Tightened ‎ (← links)
  • 05000251/LER-1984-005, :on 840412,liquid Penetrant Analysis Revealed 270 Degree Circumferential Crack on Steam Generator Feedwater Nozzles 4A & 4C.Cause Not Stated.Reducers Replaced & Internal Thickness Transitions Eliminated ‎ (← links)
  • 05000251/LER-1983-002-01, Hoisting Cable on Fuel Handling Crane of Spent Fuel Assembly X-13 Parted & Assembly X-13 Dropped Back Into Rack.Caused by Malfunction of Two Limit Switches.Switches Repaired ‎ (← links)
  • 05000251/LER-1983-021-03, /03L-0:on 831207,while Adding Nitrogen to Accumulators,Accumulator 4B Relief Valve Lifted Prematurely at Setpoint Below Tech Spec Limit.Caused by Premature Lifting of Relief Valve 858B ‎ (← links)
  • 05000251/LER-1983-020-03, /03L-0:on 831123,during Return to Operation After Addition of full-flow Recirculation Piping,Reactor Taken Critical Before Piping Hydrotested at Pump Discharge Pressure.Caused by Previous Outmoded Hydrotest ‎ (← links)
  • 05000251/LER-1983-019-03, /03L-0:on 831112,reactor Coolant Sample Taken for Isotopic Analysis of Iodine Did Not Meet Tech Spec Surveillance Frequency.Caused by Lab Technician Failure to Specify Time Frame.Personnel Instructed ‎ (← links)
  • 05000251/LER-1983-018-03, /03L-0:on 831011,while Performing Routine Surveillance Test of RHR Pump 4B,416-volt Leads to Motor Failed.Caused by Water in Motor Lead Connection Box.Source of Water Eliminated ‎ (← links)
  • 05000251/LER-1983-016-01, /01T-0:on 831004,manual Discharge Valves on Containment Spray Pumps 4A & 4B Discovered Locked in Closed Position.Caused by Personnel Error.Valve for Pump 4B Opened ‎ (← links)
  • 05000251/LER-1983-013-03, /03L-0:on 830825,while Performing Safeguards Test, Emergency Load Sequencer 4A Failed.Caused by Normal End of Life for open-circuited Timer 4A.Agastat Relay Replaced & Sequencer Tested & Returned to Svc ‎ (← links)
  • 05000251/LER-1983-010-03, W/Unit in Shutdown,Steam Generator 4A Steam Supply Valve MOV-4-1403 to Auxiliary Feedwater Pump B Failed to Open in Response to Auto Start Signal.Caused by Carbon Buildup ‎ (← links)
  • 05000251/LER-1983-006-03, /03L-0:on 830705,following Low Pressure Alarm, Accumulator 4B Pressure Found Below Tech Spec Limit.Caused by Partially Opened Valve HCV-4-936 & Leaking Ball Valve 937.Valve 937 Replaced ‎ (← links)
  • 05000251/LER-1983-022-03, /03L-0:on 831219,routine Sample of Boric Acid Storage Tank Boron Concentration Revealed Three Tanks Exceeding Tech Spec Limits.Caused by Lack of Communication Between Chemistry & Operations Personnel ‎ (← links)
  • 05000251/LER-1983-008-03, /03L-0:on 830806,automatic Turbine Runback to 70% Power Occurred When Rod Cluster N-9 in Shutdown Bank a Dropped.Caused by RCS Leakage from Upper Control Rod N9 Drive Mechanism Housing Vent Valve ‎ (← links)
  • 05000251/LER-1983-009-03, /03L-0:on 830803,steam Generator 4A Blowdown Isolation Valve CV-4-6275A Failed to Close Upon Blowdown Isolation Signal.Caused by Instrument Air Isolation to Valve Actuator.Instrument Air Supply Restored ‎ (← links)
  • 05000251/LER-1983-007-03, /03L-0:on 830803,during Routine Temp Reduction on Pressurizer Relief Tank Prior to Pumping,High Level Alarm Received Followed by Rupturing of Rupture Discs.Caused by Overpressurization.Ruptured Disc Replaced ‎ (← links)
  • 05000251/LER-1983-011-03, /03L-0:on 830809,both PORVs Out of Svc & Closed for Longer than 24 H W/Rcs Temp Less than 275 F.Caused by Lack of Coordination Between Maint & Operations Depts. RCS Drain Down Initiated ‎ (← links)
  • 05000251/LER-1983-001-01, /01T-0:on 830331,during Refueling Shutdown,Field Discrepancies Identified in Platform Steel Inside Containment.Caused by Improper Installation of Bolts on Platform Framing Steel.Repairs Being Developed ‎ (← links)
  • 05000251/LER-1983-005-01, /01T-0:on 830601,mechanical Maint Supervisor Determined That safety-related Snubber Inoperable Due to Incomplete Mod to Attachment.Caused by Personnel Error & Procedure Deficiencies.Mod Completed ‎ (← links)
  • 05000251/LER-1982-009-03, /03L-0:on 820623,biweekly Testing for Tave & Delta T Protection Channel Was Completed 2 Days After Latest Date Allowable.Caused by Computation Using Completion Date for Previous Test.Channel Test Completed 820625 ‎ (← links)
  • 05000251/LER-1982-014-03, /03L-0:on 821003,boron Injection Tank Circuit Found Below Tech Spec Limit of 145 F.Plant supervisor- Nuclear Not Promptly Notified.Caused by Inadequate Training & Info Dissemination to Personnel ‎ (← links)
  • 05000251/LER-1982-013-03, /03L-0:on 820906,RCS Experienced Rapid Decrease in Pressure.Caused by Failed Open Pressurizer Spray Valve. Reactor Manually Tripped & Automatic Safety Injection Actuated.Pressure Control Regained Using Charging Pumps ‎ (← links)
  • 05000251/LER-1982-011-03, /03L:on 820805,low Pressure Alarm (Set at 625 Psig) Received on 4B Accumulator.When Supply & Fill Valves Opened,Accumulator Pressure Dropped to 460 Psig. Caused by Loose Setting on Control Potentiometer ‎ (← links)
  • 05000251/LER-1981-014-02, /02T-0:on 811123,defective Area of Large Aggregate W/Inadequate Fines Found in Containment Liner Plate Concrete Cover.Caused by Inadequate Cementation of Original Pour as Result of Defective Concrete Batch ‎ (← links)
  • 05000251/LER-1982-010-03, /03L-0:on 820713,camera Insp of Steam Generators Revealed Foreign Objects & Minor Tube Damage.Leak & Minor Tube Damage Caused by Foreign Objects Near Tube Sheet Elevations.Metal Impact Monitoring Sys Installed ‎ (← links)
  • 05000251/LER-1982-008-03, /03L-0:on 820608,disc Stud Nut on Main Feedwater Check Valve CV-4-2900 Found Missing.Caused by Failure of Nut Locking Device.New Locking Device Installed ‎ (← links)
  • 05000251/LER-1982-007-01, /01T-0:on 820522,while Boron Injection Tank Recirculating W/Boric Acid Storage Tank C,Low Boron Concentration Found in Both Tanks.Caused by MOV-4-867B Being Open One Turn.Valve Manually Closed ‎ (← links)
  • 05000251/LER-1982-006-01, /01T-0:on 820509,boron Concentration Found Lower than Min Allowable Concentration During Routine Chemical Analysis of Boron Injection Tank Sample.Caused by Plugging of Normal Recirculation Supply Line ‎ (← links)
  • 05000251/LER-1982-005-03, /03L-0:on 820414,when Attempting to Fill Condensate Storage Tank After Low Level Alarm,Level Fell Below Acceptable Limit.Caused by Open Manual Valve DWDS-001 Allowing Flow to Demineralized Water Storage Tank ‎ (← links)
  • 05000251/LER-1982-005, Forwards LER 82-005/03L-0 ‎ (← links)
  • 05000251/LER-1982-004-01, /01T-0:on 820408,while Operating at Full Power, Routine Sample Analysis Found Boron Concentration in Boron Injection Tank Lower than Tech Specs.Caused by Boric Acid Obstructing Flow Path.Line Flushed W/Steam ‎ (← links)
  • 05000251/LER-1982-004, Forwards LER 82-004/01T-0 ‎ (← links)
  • 05000251/LER-1982-003-01, /01T-0:on 820331,deficiency Involving Supports Associated W/Component Cooling Water Sys Found.Max Stress Would Exceed Acceptance Criteria on Supports.Cause Not Stated.Mod Implemented to Support Piping ‎ (← links)
  • 05000251/LER-1982-003, Forwards LER 82-003/01T-0 ‎ (← links)
  • 05000251/LER-1981-017-03, /03L-0:on 811222,boron Injection Tank Circuits Found Out of Calibr.Cause Unknown.Open Circuit Repaired, Tested & Returned to Svc ‎ (← links)
  • 05000251/LER-1981-017, Forwards LER 81-017/03L-0 ‎ (← links)
  • 05000251/LER-1982-001-01, /01T-0:on 820105,D Motor Control Ctr Tripped Due to Phase to Phase Fault Associated W/Bus.Caused by Entrance of Metal Fish Tape Through Unused Conduit.Motor Control Ctr re-energized.Unused Conduit Capped ‎ (← links)
  • 05000251/LER-1982-001, Forwards LER 82-001/01T-0 ‎ (← links)
  • 05000251/LER-1981-016-03, /03L-0:on 811204,for Approx 4-h,condensate Storage Tank Vol Was Lower than Tech Spec.Caused by Disassembling & Closing Control Valve Associated W/Makeup Flow to Hotwell During Maint.Mods Scheduled ‎ (← links)
  • 05000251/LER-1981-016, Forwards LER 81-016/03L-0 ‎ (← links)
  • 05000251/LER-1981-015-03, /03L-0:on 811128,two Overpressure Conditions Developed for Which Overpressure Mitigating Sys Failed to Operate.Caused by Failed Summator on Sys Circuitry Coupled W/Inadvertently Isolated Pressure Transmitter ‎ (← links)
  • 05000251/LER-1981-012-03, /03L-0:on 811124,during Safeguard Sys Testing,Bus Clearing Relays Did Not Pick Up 4A Bus.Emergency Diesel Generator Did Not Close in on 4A Bus.Caused by Malfunction of 4kv Breaker Auxiliary Switches Associated W/Bus Logic ‎ (← links)
  • 05000251/LER-1981-012, Forwards LER 81-012/03L-0 ‎ (← links)
  • 05000251/LER-1981-013-01, /01T-0:on 811116,during Refueling Operations, Containment Momentarily Breached by Having Both Inside & Outside Doors of Personnel Hatch Open.Caused by Disabled Dog Ear Positioner in Air Lock Side.Dog Ear Repositioned ‎ (← links)
  • 05000251/LER-1981-013, Forwards LER 81-013/01T-0.Detailed Event Analysis Encl ‎ (← links)
  • 05000251/LER-1981-011-01, /01T-0:on 811021,high Head Safety Injection Line to Cold Legs Found to Be Obstructed During Full Flow Test on Discharge Check Valve of Pumps.Caused by Reduced Temp Due to Missing Insulation Near 4-inch Tee at Bit Inlet ‎ (← links)
  • 05000251/LER-1981-011, Forwards LER 81-011/01T-0 ‎ (← links)
  • 05000251/LER-1981-010-03, /03L-0:on 810903,while Surveillance Testing, Auxiliary Feedwater Pump a Could Not Be Properly Tripped & Was Removed for Repair.Caused by Loose Set Screw & Misaligned Yoke.Yoke & Set Screw Repaired ‎ (← links)
  • 05000251/LER-1981-010, Forwards LER 81-010/03L-0 ‎ (← links)
  • 05000251/LER-1982-012-01, /01T-0:on 820831,clearance Found Denoting Inoperability of safety-related Heat Tracing Circuit Associated W/Boric Acid Flow Path to Chemical & Vol Control Sys Blender.Caused by Personnel Error.Circuit Repaired ‎ (← links)
  • 05000251/LER-1982-012, Forwards LER 82-012/01T-0 ‎ (← links)
  • 05000251/LER-1983-004-03, /03L-0:on 830526,valve MOV-4-1405 Failed to Open During Routine Test of Auxiliary Feedwater Pump B.Caused by High Resistance Across Contacts Inside Motor Operator. Contacts Cleaned & Valve Tested ‎ (← links)
  • 05000251/LER-1981-009-03, /03L-0:on 810728,bus 4A Failed to Transfer Properly (Startup Acb 4AA05 Did Not Close After Auxiliary Acb 4AA02 Tripped).Probably Caused by Transfer Inhibit Relay 162/4A2 W/Loose Crimp on Coil Wire.Relay Replaced ‎ (← links)
  • 05000251/LER-1981-009, Forwards LER 81-009/03L-0 ‎ (← links)
  • 05000251/LER-1981-008-03, /03L-0:on 810717,while Performing Instrumentation Repairs on Pressurizer Spray Valve PCV-4-455B,RCS Leakage Discovered in Unused & Capped Packing Leakoff Line.Caused by Failure of Stem Seal Bellows & Crack in Nipple ‎ (← links)
  • 05000251/LER-1981-008, Forwards LER 81-008/03L-0 ‎ (← links)
  • 05000251/LER-1981-001-03, /03L-0:on 810112,during Startup,For 4-h,condensate Storage Tank Contained Less than 185,000 Gallons Required by Tech Spec 3.8.1.C.Caused by Increased Water Demand During Low Power Physics Testing Exceeding Treatment Plant Ou ‎ (← links)
  • 05000251/LER-1981-001, Forwards LER 81-001/03L-0 ‎ (← links)
  • 05000251/LER-1980-006, Forwards LER 80-006/03L-0 ‎ (← links)
  • 05000251/LER-1981-015, Forwards LER 81-015/03L-0.Detailed Event Analysis Encl ‎ (← links)
  • 05000251/LER-1979-015, Forwards LER 79-015/03L-0 ‎ (← links)
  • 05000251/LER-2018-001, Inoperable Auxiliary Feedwater Steam Supply Flowpath ‎ (← links)
  • 05000251/LER-1989-011-01, :on 890915,manual Reactor Trip Initiated When Control Rods Failed to Insert in Automatic or Manual in Response to Sudden Turbine Power Decrease.Caused by Inadequate Field Installation ‎ (← links)
  • 05000251/LER-1997-002-02, :on 970423,automatic Reactor Tripped.Caused by Actuation of Turbine Overspeed Protection Circuit. Administrative Procedures Governing Inadequate Work Controls Will Be Revised to Capture Lessons Learned ‎ (← links)
  • 05000251/LER-1997-001-02, :on 970327,ECCS Recirculation Loop Leakage Was Found to Be in Condition Outside Design Basis Due to Gasket Movement During Installation During Spring 1966 Reassembly. Gasket Replaced & Pump Tested ‎ (← links)
  • 05000251/LER-1996-001-03, :on 960409,manual RT Occurred Due to Turbine Governer Control Oil Perturbation.Disassembled & Inspected Governor Valve for Cleanliness & Corrosion Products ‎ (← links)
  • 05000251/LER-1994-006-02, :on 941130,Unit 4 Tripped Automatically.Caused by Failure of Flexible Link Connection Between Main Generator B Phase Bus & Associated Isolated Phase Bus Bar. All Bolts on Flexible Link Checked ‎ (← links)
  • 05000251/LER-1994-005-02, :on 940924,Unit 4 Manually Tripped.Caused by Manual Actuation.Light Bulb & Socket Replaced ‎ (← links)
  • 05000251/LER-1994-004-02, :on 940923,Unit 4 Tripped Automatically from Rated Power.Caused by Faulty Regulator Transistor.Faulty Backup Power Supply Replaced & Maint History for Power Supplies Reviewed ‎ (← links)
  • 05000251/LER-1994-003, :on 940318,ARPI Indicated Greater than Twelve Steps Deviation from Associated Group Counter.Caused by Rod Position Indication Varying W/Temp.Apris Adjusted.W/ ‎ (← links)
  • 05000251/LER-1994-002-01, :on 940310,personnel Discovered Indication of Boric Acid on a Flux Mapper Guide Tube.Caused by Tgscc. Plant Shut Down & Leaking Guide Tube Repaired ‎ (← links)
  • 05000251/LER-1994-001-02, :on 940223,Analog Channel Operational Test Not Performed within TS Surveillance Interval.Caused by Scheduling Error.Maint Procedures Modified to Display Required Date of Surveillance ‎ (← links)
  • 05000251/LER-1993-003-03, :on 930816,Turbine Trip/Rt Occurred Due to Personnel Error in Which High Pressure Feedwater Heaters Were Not Returned to Svc Correctly.Counseled Involved Operators & Revised Procedure ‎ (← links)
  • 05000251/LER-1993-002-03, :on 930622,RT Occurred Due to Manual Turbine Trip.Installed Guard Preventing Inadvertent Operation of Auxiliary Governor Trip Lever ‎ (← links)
  • 05000251/LER-1993-001-03, :on 930222,continuous Fire Watch Not Established within 1 H Per Ts.Caused by Personnel Error. Procedure 0-ADM-016.3 Will Be Revised by 930401 to Reflect Actual Verification of Continuous Fire Watch ‎ (← links)
  • 05000251/LER-1992-009, :on 921117,measured Prestress Force on Containment Tendon Lower than Predicted Lower Limit.Caused by Increased Tendon Wire Steel Relaxation Loss at Higher Tendon temp.Lift-off Forces Restored ‎ (← links)
  • 05000251/LER-1992-010-02, :on 921121,an Automatic Start of 4B EDG Occurred During 3B EDG Safeguards Test.Caused by Inadequate Procedure.Administrative Procedure 0-ADM-501 Will Be Revised ‎ (← links)
  • 05000251/LER-1992-007-01, :on 920929,AFW Actuation Occurred.Caused by Loss of Suction Pressure to Main Feedwater Pump.Procedures Re Condensate Polisher Sys Revised ‎ (← links)
  • 05000251/LER-1992-008-01, :on 921005,lift of Pressurizer PORV PCV-4-455C & Isolation of MOV-4-751 Residual Heat Removal Suction Overpressure Mitigating Sys Surveillance Occurred Due to Personnel Error.Specialist Counseled ‎ (← links)
  • 05000251/LER-1992-006-03, :on 920927,identified That Required Surveillance Not Performed Per TS 4.5.2.b.1.Caused by Personnel Error.All Surveillances in Sys Verified to Have Been Performed Per TS ‎ (← links)
  • 05000251/LER-1992-005-04, :on 920902,while Recovering from Hurricane Andrew,Continuous Fire Watch Not Maintained for Inoperable Fire Suppression Sys.Caused by Personnel Error.Fire Watch watch-stander Reinstructed & Meeting Held ‎ (← links)
  • 05000251/LER-1992-006, :on 911029,AFW Pumps Autostarted Following Trip of Only Operating MFW Pump for Unit 4.Caused by Trip of 4A MFW Pump Upon Loss of Suction Pressure.Condensate Polishing Sys Bypassed ‎ (← links)
  • 05000251/LER-1992-003, :on 920224,27 & 0313,post Maint Testing of Valve & Refueling Water Purification Pump Was Not Completed in Accordance W/Asme Requirements.Caused by Cognitive Personnel Error.Valves Tested Successfully ‎ (← links)
  • 05000251/LER-1992-004-01, :on 920326,reactor Trip Occurred,Resulting in Train B SI & Train B Containment Phase a Isolation.Caused by Worn Test Switch & Procedural Inadequacy.Switch Replaced & Procedure Revised ‎ (← links)
  • 05000251/LER-1992-003-01, :on 920224 & 27,discovered That Component Cooling Water Channel Head Drain Valves Not Post Installation Tested Per ASME Code & Ts.Caused by Personnel Error.Personnel Trained & Records Revised ‎ (← links)
  • 05000251/LER-1992-002-01, :on 920302,emergency Diesel Generator 4B Declared Inoperable Due to Inadequate Surveillance of Valve 3434B on 920130.Caused by Personnel Error.Surveillance Procedures Revised & Review Process Examined ‎ (← links)
  • 05000251/LER-1991-007, :on 911210,4A Sequencer Found in Condition Where Automatic Testing Feature Was Not in Svc Due to Failed Sequencer Auto Test Output Card Relay.Subj Card Replaced & Auto Test Feature Disabled ‎ (← links)
  • 05000251/LER-1992-001-01, :on 920202,discovered That Rod Cluster Control Indicators Not in Agreement W/Demand Indication.Caused by Temp Variation in Indications Inherent to Sys design.In-core Flux Maps Performed & Indications Adjusted ‎ (← links)
  • 05000251/LER-1991-007-02, :on 911210,completion of TS Required Shutdown Due to Failure of 4A Load Sequencer.Caused by Auto Test Output Card.Unit Shut Down on 911210 & Output Contact Card Replaced ‎ (← links)
  • 05000251/LER-1991-006-02, :on 911029,AFW Pumps Autostarted Following Low Suction Pressure Trip of Main Feedwater Pump Due to Mechanical Failure of Regulator to Condensate Polishing Vessel Inlet Valve.Cps Bypassed ‎ (← links)
  • 05000251/LER-1991-002-03, :on 910107 & 0729,permanent Magnet Generator Failed During Performance of Emergency Diesel Generator 4A Tests.Caused by Misalignment of Drive Shaft & Ground in Voltage Regulator.New Drive Shaft Installed ‎ (← links)
  • 05000251/LER-1991-005-01, :on 910809,containment & Control Room Ventilation Sys Isolated W/Both Units Defueled.Caused by Personnel Error.Const Personnel Working in Control Room Immediately Removed from Jobs for Training ‎ (← links)
  • 05000251/LER-1991-004-02, :on 910720,containment Isolation Signal Generated When Fuse Was Installed in Containment Isolation Relay Rack.Caused by Using Inadequate Procedure.Procedures Revised ‎ (← links)
  • 05000251/LER-1990-014, :on 901107,crack Discovered in Coolant Water Flexible Hose Weld.Caused by Manufacturing Defect.New Flexible Cooling Water Hoses Successfully Retested During Remaining EDG Acceptance Tests ‎ (← links)
  • 05000251/LER-1991-003-02, :on 910626,bus Lockout Resulted in de-energizing of 4C Intake Cooling Water Pump & 4C CCW Pump. Caused by Inadequate Administrative Controls.Work in Area of Relay That Actuated Was Stopped ‎ (← links)
  • 05000251/LER-1990-014-01, :on 901107,crack Approx Three Inches Discovered in Coolant Water Flexible Hose Flange Weld.Caused by Mfg Defect.New Flexible Hose Assemblies Received & Installed on 4A & 4B EDGs ‎ (← links)
  • 05000251/LER-1990-012-01, :on 901221,emergency Diesel Generator Acceptance Test Stopped Due to Declining Coolant Water Level.Caused by Coolant Manifold.Defective Manifold Replaced by Vendor ‎ (← links)
  • 05000251/LER-1991-001-01, :on 910313,startup Transformer Deenergized Due to Const Activities Taking Place to Modify Control Room Control Board.Event Response Team Appointed to Complete Investigation ‎ (← links)
  • 05000251/LER-1990-011-01, :on 901113,containment Spray Pumps 4A & 4B Placed Out of Svc in Violation of Tech Spec 3.4.2.a.1.Pump 4B Had No Oil in Bearing Oiler.Cause Undetermined.Bearing Oiler Refilled W/Oil ‎ (← links)
  • 05000251/LER-1990-010-01, :on 900910,Tech Spec 3.0.1 Entered Due to Train B Undervoltage Protection Circuit Being Inoperable ‎ (← links)
  • 05000251/LER-1990-009-01, :on 900710,action Requirement of Tech Spec 3.3.1 Re Containment Airlock Pressure Test Not Met.Caused by Work Control Deficiencies.Computer Program Updated to Print Caution Statement on Work Orders ‎ (← links)
  • 05000251/LER-1990-002, :on 900228,Unit 4 post-accident Containment Vent Remained Inoperable More than 7 Days.Caused by Personnel Error.Operating Procedure 13404.1, Local Leak Rate Tests, Revised ‎ (← links)
  • 05000251/LER-1990-008-02, :on 900812,automatic Reactor Trip on low-low Steam Generator Level Occurred Due to Loss of Steam Generator 4A Feedwater Pump.Caused by Incorrect Setpoint on Agastat Trip Delay.Condensate Pump Repaired ‎ (← links)
  • 05000251/LER-1990-007-02, :on 900726,component Cooling Water Pump 4A Automatically Started.Caused by Error Made by Nonlicensed Personnel.Pressure Controller PC-4-611 Recalibrated ‎ (← links)
  • 05000251/LER-1990-006-02, :on 900705,automatic Start of Component Cooling Water Pump 4B Occurred Due to Low Pump Discharge Header Pressure.Caused by Personnel Error.Responsible Individual Required to Review Procedure ‎ (← links)
  • 05000251/LER-1990-005-02, :on 900605,intake Cooling Water Flow Rate to Component Cooling Water HXs Verified to Be Below Caution Level.Caused by Inadequate Administrative Controls.Special Instructions Initiated for supervisor-nuclear ‎ (← links)
  • 05000251/LER-1990-004, :on 900526,reactor Manually Tripped During Restoration Phase of Turbine Valve Test.Caused by Personnel Error.Procedures 3-OSP-089 & 4-OSP-089 Revised to Clarify Intent of Step 7.2.59 ‎ (← links)
  • 05000251/LER-1990-003-02, :on 900409,reactor Protection Sys Actuation Occurred Due to Failure of Reactor Coolant Pump Underfrequency Relay Power Supply Capacitor.Caused by Open Supply Breakers.Relay Replaced ‎ (← links)
  • 05000251/LER-1990-002-02, :on 900228,post-accident Containment Vent Found Inoperable for 13 Days,Contrary to Tech Spec Limit. Caused by Personnel Error.Cautions Added to Local Leak Rate Test Procedure ‎ (← links)
  • 05000251/LER-1990-001-03, :on 900228,isolation Valve for Intake Cooling Water (Icw) Pump 4C Discharge Line Pressure Indicator Was Not Correct Valve Type.Caused by Personnel Error.Valve Replaced W/Correct Valve Type ‎ (← links)
  • 05000251/LER-1989-006, :on 890713,intake Cooling Water Flow to Component Cooling Water HXs Degraded to Below Design Basis Flow Rate for 15 Minutes.Caused by Flow Obstruction Near Header Isolation Valve.Valve Replaced ‎ (← links)
  • 05000251/LER-1989-013-01, :on 891020,discovered That Quarterly Inservice Testing of Intake Cooling Water Isolation Valves to HXs Not Performed.Caused by Personnel Error.Valves Tested & Determined to Meet Function ‎ (← links)
  • 05000251/LER-1989-012-01, :on 890927,one of Two wide-range Containment Water Level Indicators Found Deenergized.Caused by Personnel Error.Bump Covers Will Be Placed on Containment Level Receivers ‎ (← links)
  • 05000251/LER-1985-002-01, :on 850129,malfunction Caused Emergency Diesel Generator a to Be Out of Svc So Vital Buses 3A & 4A Did Not Have Access to Onsite Emergency Power.Caused by Short in Panel Light Socket.Plant Change/Mod Initiated ‎ (← links)
  • 05000251/LER-1989-003, :on 890505,reactor Protection Sys Actuation Occurred While Performing Procedure 4-SMI-071.4.Caused by Lifted Leads in Turbine Stop Valves Position Sensing Circuitry.New Procedure Developed ‎ (← links)
  • 05000251/LER-1989-010-01, :on 890906,nuclear Instrumentation Sys Rod Drop Signal Received Resulting in Turbine Runback.Caused by Inadequate Procedure Which Did Not Provide Guidance Re Rate of Reduction in Reactor Power.Tubes Plugged.W/Undtd Ltr ‎ (← links)
  • 05000251/LER-1989-009-01, :on 890823,boric Acid Transfer Pump Seal Pot Found W/No Visible Level Resulting in No Flow Path to Rcs. Caused by Design of Boric Acid Transfer Pump Double Seals. Review Continuing for Alternate Seal Design ‎ (← links)
  • 05000251/LER-1989-008-01, :on 890809,containment Spray Pump Exceeded Tech Spec Limit by Remaining Out of Svc for More than 24 H.Caused by Installation Which Led to Stresses in Motor Casing.Spray Pump 4A Replaced W/New Motor ‎ (← links)
  • 05000251/LER-1988-011-01, :on 880816,damage Occurred to Property in Excess of $2,000 Due to Spent Fuel Pool Leakage.Caused by Pump Failure Causing Vent Valve to Vibrate Open.Floor Drain Sys Cleaned.Pump & Oiler Repaired & Inspected ‎ (← links)
  • 05000251/LER-1989-007-01, :on 890713,determined That Required Visual Exam for Leakage Missed.Caused by Cognizant Field Engineer Personnel Error.Visual Exam Performed within 1 Hr.No Leakage Detected.Personnel Counseled ‎ (← links)
  • 05000251/LER-1989-006-01, :on 890713,intake Cooling Water Flow to Component Cooling Water HXs Degraded Below Design Basis Flow Rate for 15 Minutes.Caused by Failure of Header Isolation Valve 4-50-308.Valve Replaced & Pin Removed ‎ (← links)
  • 05000251/LER-1989-005-02, :on 890628,4A Accumulator Level Tech Spec Not Met Due to Wrong Redundant Level Transmitter.Caused by Personnel Error of non-licensed Operator.Transmitter Replaced W/Spare ‎ (← links)
  • 05000251/LER-1989-003-02, :on 890505,reactor Tripped During Performance of Steam Generator Protection Set III Channel Test.Cause Under Investigation.Leads Landed to Provide Signal to Reactor Protection Sys for Valve Position ‎ (← links)
  • 05000251/LER-1989-001-01, :on 890209,emergency Diesel Generator Inoperable W/Rhr 4B out-of-svc.Caused by Miscommunication Between Operations Personnel.Procedure O-OSP-023.1 Revised to Require Operability of Required Equipment ‎ (← links)
  • 05000251/LER-1987-025-02, :on 871012,containment & Control Room Ventilation Isolation Occurred.Cause by High Levels of Rb-88 in Containment Following Unit Shutdown.Particle Grab Sample Taken & Leak Rate Calculation Performed ‎ (← links)
  • 05000251/LER-1987-025-01, :on 871012,containment Vent & Control Room Ventilation Isolation Actuated.Caused by High Levels of Rb-88 in Containment Following Unit Shutdown.Containment Activity Level Returned to Normal ‎ (← links)
  • 05000251/LER-1987-010-02, :on 870522,emergency Diesel Generator auto-started During Testing of 4,160-volt Bus Undervoltage Protection Circuit.Caused by Personnel Error.Personnel Counseled & Procedure Revised ‎ (← links)
  • 05000251/LER-1987-009-02, :on 870516,diesel Generator Ready to Start Light Went Out Causing Loss of Emergency Power Supply for RHR Sys.Caused by Inadvertent Bumping of Telemand Transfer Relay 2X4-3A.Normal Power Supply Restored ‎ (← links)
  • 05000251/LER-1987-007-01, :on 870310,air Leakage During Leak Rate Testing of Personnel Hatch Exceeded Tech Spec Requirements.Caused by Malfunctioning Equilizing Valve Not Being Able to Fully Close.Valve Replaced ‎ (← links)
  • 05000251/LER-1990-013-01, :on 901212,failure of Alternate DC Supply Occurred.Caused by Failed 4A & 4B EDG Pilot Exciter Regulators.Edg 4B Returned to Vendor for Repair & Transistor Replaced ‎ (← links)
  • 05000251/LER-1991-001, :on 910313,startup Transformer Locked Out Which Caused 4A 4160 Volt Bus to de-energize.Caused by Loss of Spent Fuel Cooling & Inadequate Process Control.Procedure Revised & Training Issued ‎ (← links)
  • 05000251/LER-1991-001-02, :on 910313,unit 4 Startup Transformer Locked Out Causing Volt Bus to de-energize.Caused by Construction Activities Taking Place Modifying Control Room Control Board.Construction Work Stopped in Area ‎ (← links)
  • 05000251/LER-1989-004-01, :on 890523,RHR motor-operated Valve MOV-4-751 & RHR Normal Suction Isolation Valve Failed to Open W/Control Switch.Caused by Hydraulic Locking of Valve.Valve Modified W/Equalizing Line ‎ (← links)
  • 05000251/LER-1989-002-02, :on 890412,train a Safeguards Actuation Occurred.Caused by Reactor Control Operator Not Providing Sufficient Instructions to Prevent Safety Sys Actuations. Instruction Added to Std Clearance ‎ (← links)
  • 05000251/LER-1988-012-01, :on 880905,control Rod K-12 Dropped from 228 Steps to 0 Step,Causing Turbine Runback to 60% Power.Cause of Drop Under Investigation.Insp of Control Rod K-12 Will Be Performed During Current Refueling Outage ‎ (← links)
  • 05000251/LER-1988-010-01, :on 880819,reactor Trip Occurred Due to lo-lo Steam Generator B Level.Caused by Cognitive Personnel Error. Reactor Control Operator Counseled Re Procedural Compliance & Attention to Details ‎ (← links)
  • 05000251/LER-1988-009, :on 880816,steam Generator Feedwater Pump Tripped During Coating of Condensate Polisher Vessel 4B W/ Resin for Secondary Sys Startup.Caused by Failure of Differential Pressure Switch.Switch Replaced ‎ (← links)
  • 05000251/LER-1988-008-01, :on 880815,Phase a of Containment Isolation Train a Actuated.Caused by Wire Bundle Bouncing Contacts of Relay 4-SIA2.Actuation Signal Reset ‎ (← links)
  • 05000251/LER-1988-007-01, :on 880812,while Performing Corrective Maint, Subcritical Reactor Trip Occurred.Caused by Failure of Source Range Neutron Detector N-32.Post-trip Review Performed & Detector Replaced ‎ (← links)
  • 05000251/LER-1988-006-01, :on 880716,containment Ventilation & Control Room Ventilation Sys Isolation Occurred.Caused by Very Conservative Setpoint for R-11 Actuation.Unit Removed from Operation & Temporary Repair Effected ‎ (← links)
  • 05000251/LER-1987-015, :on 870715 & 16,failure to Deactivate Inoperable Containment Isolation Valve within 4 H as Required by Tech Specs Discovered.Caused by Personnel Error. Procedures Revised ‎ (← links)
  • 05000251/LER-1988-005-01, :on 880425,calibr of Nuclear Instrumentation Sys Power Range Detectors Performed Late.Caused by Personnel Error.Digital Data Processing Sys Repaired & Group Responsible for Performance Discussed Event ‎ (← links)
  • 05000251/LER-1988-004, Forwards Corrected LER 88-004,correcting Event Date in Block 5 of Rept Form as Submitted W/Util ‎ (← links)
  • 05000251/LER-1988-004-03, :on 880408,Tech Spec 3.5-2,Item 3.2.b Exceeded. Caused by Failure of Relays in Undervoltage Protection Scheme.Relays Replaced & Satisfactorily Tested Before Unit Shutdown Commenced ‎ (← links)
  • 05000251/LER-1988-004-02, :on 880408,Tech Spec Table 3.5-2 Requirements Exceeded.Caused by Failure of Relays 327TX/4A2 & 327TX/4A2 in Undervoltage Protection Scheme for 4A 480 Volt Load Ctr. Relays Replaced & Tested ‎ (← links)
  • 05000251/LER-1988-003-01, :on 880207,shutdown of Unit from 100% Power Commenced Due to Exceeding Requirements of Tech Spec for Having Battery Charger 4S Out of Svc.Caused by Failure of Snubber Capacitor.Capacitor Replaced ‎ (← links)
  • 05000251/LER-1988-002-01, :on 880202,containment & Control Room Ventilation Isolation Occurred.Caused by Personnel Error While Performing Mod to Remove Remote Alarm Function.Planner & Technician Involved Counselled ‎ (← links)
  • 05000251/LER-1988-001-01, :on 880129,operability Requirements of Tech Spec 3.5.1 for Steam Generator lo-lo Level Reactor Could Not Be Met.Caused by Procedural Error.Setpoints of Affected Channels Rechecked,Calibr & Procedure Revised ‎ (← links)
  • 05000251/LER-1986-015, :on 860821,auxiliary Feedwater Sys Train Declared out-of-svc Due to Failed Valves.Caused by Wire Bundle Pressed Against Contact Switch,Keeping Contact Open. Wire Bundle Relocated ‎ (← links)
  • 05000251/LER-1987-028, :on 871218,two Intake Cooling Water Pumps Declared Out of Svc Which Exceeded Limits of Tech Spec 3.4.5.Caused by Broken Lower Headshaft Coupling.Coupling Replaced & Pump Returned to Svc ‎ (← links)
  • 05000251/LER-1987-028-01, :on 871218,unit Shutdown Commenced When Two Intake Cooling Water Pumps Declared Inoperable.Caused by Broken Shaft Coupling & Frozen Bushing.Broken Shaft Coupling & 4B Icw Pump Replaced & Satisfactorily Tested ‎ (← links)
  • 05000251/LER-1987-027-01, :on 871214,steam Generator 4B Blowdown Effluent Flowrate Not Estimated.Caused by Inadequate Identification of Tech Spec Table 3.9-2 Hardware.Blowdown Secured & Ltr Re Tech Spec Compliance Methods Issued ‎ (← links)
  • 05000251/LER-1987-026-01, :on 871121,component Cooling Water (CCW) Pump 4B Autostarted During CCW Pump 4C Return to Svc.Caused by Insufficient Margin Between Operating & Setpoint Pressures.Increased Margin Initiated ‎ (← links)
  • 05000251/LER-1987-024-01, :on 871008,temp for Boric Acid Heat Tracing Circuit Number 6 Decreased Below 145 F.Caused by Cold Flushing of Crosstie Line.Flushing of Boric Acid Pump Crosstie Line Stopped & Sys Alignment Restored ‎ (← links)
  • 05000251/LER-1987-023-01, :on 870915,containment Vent & Control Room Ventilation Isolation Logic Actuated When Process Radiation Monitor Trended High.Caused by Paper Drive Jam. Paper Replaced & Paper Drive Tension Adjusted ‎ (← links)
  • 05000251/LER-1987-018, :on 870711,operation in Excess of 24 H W/ Greater than 2% Calculated Quadrant Power Tilt Ratio W/O Running Flux Map or Reducing Overpressure,Overtemp Occurred. Caused by Personnel Error.Procedure Updated ‎ (← links)
  • 05000251/LER-1987-021-01, :on 870729,process Radiation Monitor Spiked High Actuating Containment Vent & Control Room Ventilation Isolation Logic.Caused by Work Being Performed on Condenser Air Ejector Radiation Monitor.Drawer Reset ‎ (← links)
  • 05000251/LER-1987-020-01, :on 870728,discovered That Steam Generator 4A Feedwater Flow Control Valve Actuator Stem Not Properly Engaged W/Control Valve Stem.Caused by Improperly Matched Coupler Halves.Set Screw Inserted Into Block ‎ (← links)
  • 05000251/LER-1987-014, :on 870711,water Dripping from Auxiliary Feedwater(Afw) Steam Line Discovered & on 870717,AFW Train 1 Declared Inoperable.Cause of Leak Unknown.Affected Piping & Fitting Replaced ‎ (← links)
  • 05000251/LER-1987-015-01, :on 870715,technicians Failed to Deactivate Inoperable Containment Isolation Valve within 4 H as Required by Tech Specs.Caused by Personnel Error.Procedure Completion Responsibility Centralized ‎ (← links)
  • 05000251/LER-1987-016-01, :on 870715,automatic Actuation of Intake Cooling Water Pump Occurred.Caused by Ground on Pump Motor. Pump Replaced & Satisfactorily Tested ‎ (← links)
  • 05000251/LER-1987-012, :on 870705,component Cooling Water (CCW) Pump Auto Started During Engineered Safeguards Integrated Test Due to Low Header Pressure Upon Increased CCW Flow. Integrated Test Revised ‎ (← links)
  • 05000251/LER-1987-017-01, :on 870715,inadvertent Isolation of Auxiliary Feedwater Nitrogen Backup Sys Occurred.Caused by Personnel Error (Not Following Procedures).Sys Realigned to Proper Configuration Using Procedure 4-OP-065.2 ‎ (← links)
  • 05000251/LER-1987-014-01, :on 870711,dripping from Auxiliary Feedwater Steam Line Discovered.On 870714,leak Identified as Pinhole on Reducer.Cause Unknown.Fitting & Portion of Adjacent Piping Removed for Analysis ‎ (← links)
  • 05000251/LER-1987-019-01, :on 870712,turbine Runback from 89% Reactor Power to 84% Reactor Power Occurred.Caused by Spurious Spike in Rod Position Indication Sys.Faulty Solder Joint Repaired & Signal Conditioners Inspected ‎ (← links)
  • 05000251/LER-1987-018-01, :on 870712,operation in Excess of 24 H W/Greater than 2% Calculated Quadrant Power Tilt Ratio W/O Running Flux Map or Reducing Overpressure,Overtemp Occurred. Caused by Personnel Error.Personnel Counseled ‎ (← links)
  • 05000251/LER-1987-013-02, :on 870710,power Operations of 480 Volt Load Ctr Continued When Inoperable Channel Not in Tripped Condition.Caused by Failure of Relay in Undervoltage Protection Scheme.Evaluation Underway ‎ (← links)
  • 05000251/LER-1987-012-02, :on 870705,during Unit 3 Engineered Safeguards Integration Test,Auto Start of Component Cooling Water Pump 4B Occurred.Caused by Low Header Pressure on Increased Cooling Water Flow.Procedure Will Be Enhanced ‎ (← links)
  • 05000251/LER-1987-011-02, :on 870608,automatic Actuation of Component Cooling Water Pump 4C Occurred.Caused by Low Sys Pressure Due to Leak in 4A Component Cooling Water Hx.Hx Removed from Operation & Leak Repaired ‎ (← links)
  • 05000251/LER-1981-006-03, /03L-0:on 810423,snubber on Supply Steam Line to Auxiliary Feedwater Sys Observed to Have Broken Loose. Caused by Failure of Threaded Joint for Connection of Snubber Rod from Turnbuckle to Adaptor Plate.Joint Welded ‎ (← links)
  • 05000251/LER-1981-006, Forwards LER 81-006/03L-0 ‎ (← links)
  • 05000251/LER-1981-007-03, /03L-0:on 810426,component Cooling Water Surge Tank Low Level Alarm Sounded & Containment Sump Level Found Increasing.Caused by Failed Flexitallic Gasket on Inlet Flange of Excess Letdown Heat Exchanger ‎ (← links)
  • 05000251/LER-1981-007, Forwards LER 81-007/03L-0 ‎ (← links)
  • 05000251/LER-1981-004-03, /03L-0:on 810322,reactor Trip Resulted from Steam Flow/Feedwater Flow Mismatch Coincident W/Steam Generator a Low Level.Caused by Failed Solenoid Coil on Feedwater Regulator Valve.Evaluation Continuing ‎ (← links)
  • 05000251/LER-1981-004, Forwards LER 81-004/03L-0 ‎ (← links)
  • 05000251/LER-1981-005-03, /03L-0:on 810407,need for Governor Adjustment Found During Auxiliary Feedwater Pump a Test & Pump C Taken Out of Svc for IE Bulletin 79-14 Mods.Cause Not Stated. Governors Repaired ‎ (← links)
  • 05000251/LER-1981-005, Forwards LER 81-005/03L-0 ‎ (← links)
  • 05000251/LER-1980-010-03, Leakage Developed Through Crack in North Channel Cover of Component Cooling Water Heat Exchanger 4C.Caused by Corrosion.Channel Cover Replaced ‎ (← links)
  • 05000251/LER-1980-010, Forwards Updated LER 80-010/03X-1 ‎ (← links)
  • 05000251/LER-1980-007-03, Disc Stud Nut Discovered Missing from Main Stem Check Valve 4A.Caused by Failure of Associated Locking Device.Disc Studs Replaced & Improved Locking Device Installed ‎ (← links)
  • 05000251/LER-1980-007, Forwards Updated LER 80-007/03X-1 ‎ (← links)
  • 05000251/LER-1980-013-03, Updated 80-013/03X-1:on 801111,six Ionization Type Detectors Found Inoperable During Final Acceptance Testing on Modified Fire Detection Sys.Caused by Improper Electrical Contact Due to Moisture Induced Corrosion of Terminal ‎ (← links)
  • 05000251/LER-1980-013, Forwards Updated LER 80-013/03X-1 ‎ (← links)
  • 05000251/LER-1981-002-03, /03L-0:on 810214,boric Acid Flow in Normal Flowpath from Boric Acid Tanks Could Not Be Established & Low Temp Reading Found in Flowpath on 810217.Caused by Three Splices Needing Repair on Heat Tracing Circuits ‎ (← links)
  • 05000251/LER-1981-002, Forwards LER 81-002/03L-0 ‎ (← links)
  • 05000251/LER-1981-003-03, /03L-0:on 810218,leak Discovered in Rcs.Caused by Cracked Weld Between Vent Valve Line & 4A Reactor Coolant Pump Seal Supply Line.Vent Line Cut & Rewelded to Seal Line. Mod Will Be Implemented ‎ (← links)
  • 05000251/LER-1981-003, Forwards LER 81-003/03L-0 ‎ (← links)
  • 05000251/LER-1980-014-01, /01T-0:on 801126,insp Per IE Bulletin 79-14 Revealed Deficiency in Portions of Accumulator & RHR Sys Piping Inside Containment.Calculated Max Stress Exceeded Criteria.Mod Will Be Made Before Unit Returns to Svc ‎ (← links)
  • 05000251/LER-1980-014, Forwards LER 80-014/01T-0 ‎ (← links)
  • 05000251/LER-1980-012-03, /03L-0:on 801013,excessive Leakage Past Primary Packing in Charging Pump 4A Caused Pump to Be Removed from Svc.Caused by Loose Packing.Packing Replaced ‎ (← links)
  • 05000251/LER-1980-012, Forwards LER 80-012/03L-0 ‎ (← links)
  • 05000251/LER-1979-009-03, /03L-1:on 790611,mechanical Snubber on Steam Generator C Feedwater Line Found in locked-up Condition. Caused by Snubber Overload Resulting in Damage to Thrust Bearing.Snubber Will Be Replaced w/50,000 Lb Rated Snubber ‎ (← links)
  • 05000251/LER-1979-009, Forwards LER 79-009/03L-1 ‎ (← links)
  • 05000251/LER-1980-009-03, /03L-0:on 800614,during Shutdown,Low Flow Was Indicated on 4C Bypass Loop.Caused by Valve Stem Separating from Disc in Manner Which Prevented Valve from Fully Opening ‎ (← links)
  • 05000251/LER-1980-009, Forwards LER 80-009/03L-0 ‎ (← links)
  • 05000251/LER-1980-008-01, /01T-0:on 800523,review of Radiographs Per IE Bulletin 79-13 Revealed Indications of Cracking in Feedwater Nozzle to Pipe Weld on Steam Generator 4 C Reducers.Cause Not Stated.Fittings Containing Defects Are Being Replaced ‎ (← links)
  • 05000251/LER-1980-008, Forwards LER 80-008/01T-0 ‎ (← links)
  • 05000251/LER-1980-003-03, While Testing 4C Steam Generator Feedwater Control Valve,Change in Steam Generator Level Lifted Low Setpoint Valve.Valve Did Not Fully Reseat. Caused by Binding Between Lifting Gear & Release Nut ‎ (← links)
  • 05000251/LER-1980-003, Forwards Updated LER 80-003/03L-0 ‎ (← links)
  • 05000251/LER-1980-006-03, /03L-0:on 800407,during Inservice Insp Testing, Auxiliary Feedwater Pump a Failed to Deliver Flow Rate to Unit 4 Steam Generators.Caused by Control Circuit Calibr or Flow Restriction in Valve 4-20-142 ‎ (← links)
  • 05000251/LER-1980-005-03, /03L-0:on 800331,during Normal Operation,Process Radiation Monitors R-11 & R-12 Were Out of Svc for Approx 11-h.Caused by Failure of Air Sampling Blower Due to Normal Wear.Blower Replaced.Monitors Returned to Svc ‎ (← links)
  • 05000251/LER-1980-005, Forwards LER 80-005/03L-0 ‎ (← links)
  • 05000251/LER-1980-004-03, /03L-0:on 800216,while at Hot Shutdown,Condensate Storage Tank Contained Less than 85,000 Gallons for 4-h. Caused by Broken Drive Belt on Agitator.Motor Remounted to Accept Available Drive Belt ‎ (← links)
  • 05000251/LER-1980-004, Forwards LER 80-004/03L-0 ‎ (← links)
  • 05000251/LER-1980-002-03, /03L-0:on 800214,for 17-h During Hot Shutdown, Condensate Storage Tank Contained Less than 185,000 Gallons Required by Tech Specs.Caused by Failed Seal W/Resulting Gear Damage on Agitator Transmission.Agitator Was Replaced ‎ (← links)
  • 05000251/LER-1980-002, Forwards LER 80-002/03L-0 ‎ (← links)
  • 05000251/LER-1980-001-03, /03L-0:on 800121,during Semiannual Test of Fire & Smoke Detection Sys in Containment Electrical Penetration Zone 6,supply of Test Gas Became Depleted.Caused by Lack of Assurance by Maint & Supply Personnel Re Sufficient Gas ‎ (← links)
  • 05000251/LER-1980-001, Forwards LER 80-001/03L-0 ‎ (← links)
  • 05000251/LER-1979-011-03, Charging Sys Performance Noted to Be Degraded During Routine Startup Operation.Caused by Ruptured Diaphragm & Damaged O-ring on Valve.Valve Repaired & Pumps Vented ‎ (← links)
  • 05000251/LER-1979-011, Forwards Updated LER 79-011/03X-1 ‎ (← links)
  • 05000251/LER-1979-017-03, /03L-0:on 790903,condensate Water Tank Contained Less than 185,000 Gallons Required by Tech Specs.Caused by Increased Water Demand for Steam Generator Blowdown & Reduced Water Treatment Plant Output ‎ (← links)
  • 05000251/LER-1979-017, Forwards LER 79-017/03L-0 ‎ (← links)
  • 05000251/LER-1979-015-03, /03L-0:on 790829,during Power operation,4A Boric Acid Transfer Pump Tripped on Thermal Overload & Declared Inoperable.Caused by Boric Acid Solidification in Recirculation Line.Recirculation Line Insulated ‎ (← links)
  • 05000251/LER-1979-016-03, /03L-0:on 790830,boric Acid Transfer Pump Failed to Start.Caused by Malfunction of Line Starter.Contacts Were Cleaned & Pump Was Returned to Svc ‎ (← links)
  • 05000251/LER-1979-016, Forwards LER 79-016/03L-0 ‎ (← links)
  • 05000251/LER-1979-018-03, /03L-0:on 790911,charging Pump 4C Removed from Svc Due to Excessive Seal Leakage.Cause Not Given.Seal Was Replaced & Pump Returned to Svc.Evaluation Continues ‎ (← links)
  • 05000251/LER-1979-018, Forwards LER 79-018/03L-0 ‎ (← links)
  • 05000251/LER-1979-014-01, /01T-0:on 790828,during Performance of Evaluation to Place Spent Fuel Pit Purification Demineralizer in Svc, 3,000 Gallon Overflow Occurred.Caused by Incomplete Communication & Failure to Follow Procedure.Unit Cleaned ‎ (← links)
  • 05000251/LER-1979-014, Forwards LER 79-014/01T-0 ‎ (← links)
  • 05000251/LER-1979-013-03, /03L-0:on 790815,charging Pump 4A Removed from Svc Due to Excessive Seal Leakage.Cause Under Investigation. Seal Was Replaced & Pump Tested & Returned to Svc ‎ (← links)
  • 05000251/LER-1979-013, Forwards LER 79-013/03L-0 ‎ (← links)
  • 05000251/LER-1979-012-03, /03L-0:on 790806,periodic Test of T & delta-T Not Completed within Required Time Limit Due to Investigation of Unit Trip.Surveillance Completed Following Recovery from Unit Trip ‎ (← links)
  • 05000251/LER-1979-012, Forwards LER 79-012/03L-0 ‎ (← links)
  • 05000251/LER-1979-008-03, /03X-1 on 790526:while Safeguards Sys Was Being tested,4A 4,160-volt Bus Failed to Strip in Required Time, Causing Emergency Diesel Generator to Stop.Cause Not Determined.Testing Procedures Revised ‎ (← links)
  • 05000251/LER-1979-008, Forwards LER 79-008/03X-1 ‎ (← links)
  • 05000251/LER-1978-008, Update to LER 78-008/01X-1 on 780828:restricting Orifices Not Installed in Branch Connections from Containment Spray Headers to Emergency Containment Filter Spray Sys.Caused by Inadvertent Omission.Qc/Qa Program Initiated ‎ (← links)
  • 05000251/LER-1979-010-01, /01T-0 on 790626:NSSS Vendor Notified Util of Potential Level Bias Which Could Delay Reactor Trip & Feedwater Initiation or Cause False Level Indications. License Amend Will Be Proposed to Increase Sys Setpoint ‎ (← links)
  • 05000251/LER-1979-010, Forwards LER 79-010/01T-0 ‎ (← links)
  • 05000251/LER-1978-007-03, /03L-0 on 780710:for 11.5-h,condensate Storage Tank Level Was Below Tech Spec Limits.Caused by Condenser Leaks in Both Units.Water Treatment Was Shut Down & Storage Tanks Filled ‎ (← links)
  • 05000251/LER-1978-007, Forwards LER 78-007/03L-0 ‎ (← links)
  • 05000251/LER-1979-007-01, /01T-0 on 790519:inoperable Pipe Support 4-VCH-105 Reported by Insp Team.Cause Unknown.Pipe Support to Be Restored Per Approved Procedures ‎ (← links)
  • 05000251/LER-1979-006-03, /03L-0 on 790322:packing leak-off Observed on Three Valves.Cause Undetermined for Two Valves.Leaking Packing on Third Due to Broken Bellows Seal.Unit in Reeling Shutdown;Repairs Will Be Made Before Return to Power ‎ (← links)
  • 05000251/LER-1979-006, Forwards LER 79-006/03L-0 ‎ (← links)
  • 05000251/LER-1979-005-03, /03L-0 on 790322:process Radiation Monitors R-11 & R-12 Were Out of Svc.Caused by Failure of Air Sampling Blower Which Supplies Monitors.Blower Replaced & Monitors Returned to Svc ‎ (← links)
  • 05000251/LER-1979-005, Forwards LER 79-005/03L-0 ‎ (← links)
  • 05000251/LER-1979-004-03, /03L-0 on 790315:vendor Reported Main Steam Line Mechanical Snubber,Returned for Routine Testing,Was in locked-up Condition.Caused by Damaged Thrust Bearing. X-stop Adjusted ‎ (← links)
  • 05000251/LER-1979-002-03, /03L-0 on 790310:during Cold Shutdown,Cracks Observed in 4B Charging Pump Suction Piping.Probably Caused by Design/Installation of Positive Displacement Pumps. Welds Repaired & Mods Made to Reduce Stresses ‎ (← links)
  • 05000251/LER-1979-004, Forwards LER 79-004/03L-0 ‎ (← links)
  • 05000251/LER-1979-003-03, /03L-0 on 790315:during Normal Operation,Crack Observed in 4C Charging Pump Suction Piping.Caused by Design/Installation of Pumps Resulting in Operational Pressure Pulsation/Vibration Effects.Weld Repaired ‎ (← links)
  • 05000251/LER-1979-002, Forwards LER 79-002/03L-0 ‎ (← links)
  • 05000251/LER-1979-003, Forwards LER 79-003/03L-0 ‎ (← links)
  • 05000251/LER-1979-001-03, /03L-0 on 790125:4A Boric Acid Transfer Pump Tripper on Thermal Overload Inoperable.Caused by Incomplete Reinstallation of Recirculation Line Insulation.New Recirculation Line Installed ‎ (← links)
  • 05000251/LER-1979-001, Forwards LER 79-001/03L-0 ‎ (← links)
  • 05000251/LER-1978-016-03, /03L-0 on 781219:process Radiation Monitors R-11 & R-12 Were Out of Svc for About 18-h.Air Sampling Blower Which Monitors R-11 & R-12 Failed Due to Normal Wear ‎ (← links)
  • 05000251/LER-1978-016, Forwards LER 78-016/03L-0 ‎ (← links)
  • 05000251/LER-1978-010-03, /03L-1 on 780911:Spent Fuel Pit Cooling Pumps Mech Seal Failed Causing 150 Gallons of Radioactively Contaminated Water to Leak to Paved Area Outside Pump Room Caused by Inadequately Lubricated Pump Bearing ‎ (← links)
  • 05000251/LER-1978-010, Forwards LER 78-010/03L-1 ‎ (← links)
  • 05000251/LER-1978-015-01, /01T-0 on 781106:Boron Injection Tank(Bit)Sample Showed Low Boron Level.Exact Cause Is Unknown,But It Is Suspected the Actual Bit Concentration Was Proper & the Sample Was Diluted & Invalid ‎ (← links)
  • 05000251/LER-1978-015, Forwards LER 78-015/01T-0 ‎ (← links)
  • 05000251/LER-1978-014-03, /03L-0 on 781002:condensate Storage Tank(Cst)Fell to 182,000 Gallons Because of Water Demand Increase for Steam Generator Blowdown Resulting from Cation Resin Bed Regeneration.Cst Filled After Resin Bed Regeneration ‎ (← links)
  • 05000251/LER-1978-014, Forwards LER 78-014/03L-0 ‎ (← links)
  • 05000251/LER-1978-013-03, /03L-0:on 780929,condensate Storage Tank Held Less than 185,000 Gallons for About 8 H.Caused by Leaks in Condenser Tubes,Necessitating Increased Steam Generator Blowdown.Flow Demand Exceeded Output of Treatment Plant ‎ (← links)
  • 05000251/LER-1978-013, Forwards LER 78-013/03L-0 ‎ (← links)
  • 05000251/LER-1978-011-03, /03L-0:on 780920,Preventive Maint Checks of MSIV Solenoid Valves Revealed Defective Coils.Caused by High Temp & Moisture in Area.Addl Preventive Maint Planned ‎ (← links)
  • 05000251/LER-1978-011, Forwards LER 78-011/03L-0 ‎ (← links)
  • 05000251/LER-1978-012-01, /01T-0:on 780927,no Adverse Affect Noted from Substitution of Fuel Assembly N-07 for N-04 in Core Position F-14.Reload 5 Safety Evaluation Remains Valid ‎ (← links)
  • 05000251/LER-1978-012, Forwards LER 78-012/01T-0 ‎ (← links)
  • 05000251/LER-1978-009-03, /03L-0 on 780831:20 Safety Related Hydraulic Snubbers Failed Functional Tests Due to Control Block Poppet Valve & Relief Valve Malfunctions & Excessive Main Cylinder Wear.Hydraulic Type Replaced W/Mechanical Type Snubbers ‎ (← links)
  • 05000251/LER-1978-009, Forwards LER 78-009/03L-0 ‎ (← links)
  • 05000251/LER-1978-008-01, /01T-0 on 780911:Restricting Orifices Not Installed in Branch Connections from Containment Spray Headers to Emergency Containment Filter Spray Sys.Proper Orifices Will Be Installed.(Encl to 7809220126) ‎ (← links)
  • 05000251/LER-1917-001, Regarding Manual Reactor Trip Due to Lowering Steam Generator Level Caused by Loss of Flow Regulating Valve Positioner Control ‎ (← links)
  • 05000251/LER-1980-011-03, /03L-0:on 800818,during Surveillance Testing,Six Ionization Detectors in 4W Electrical Penetration Room Found Inoperable.Caused by Improper Installation of Upgrade to Fire Protection Sys ‎ (← links)
  • 05000251/LER-1980-011, Forwards LER 80-011/03L-0 ‎ (← links)
  • 05000251/LER-2016-001, Regarding Technical Specification Action Not Taken for Unrecognized Inoperable Reactor Protection Instrument Channel ‎ (← links)
  • 05000251/LER-2015-002, Regarding Reactor Trip Resulting from Generator Differential Lockout ‎ (← links)
  • 05000251/LER-2015-001, Regarding Automatic Auxiliary Feedwater System Actuation During a Planned Reactor Trip ‎ (← links)
  • 05000251/LER-2014-003, Regarding Emergency Containment Cooler Safety Function Impacted During Breaker Replacement ‎ (← links)
  • 05000251/LER-2014-002, Regarding Automatic Actuation of the Reactor Protection System Due to Low Main Condenser Vacuum ‎ (← links)
  • 05000251/LER-2014-001, Regarding Incorrect Feedwater Flow Transmitter Calibration Caused RPS Channels to Be Inoperable ‎ (← links)
  • 05000251/LER-2013-002, Reactor Trip Due to Loss of Offsite Power Resulting from Generator Testing ‎ (← links)
  • 05000251/LER-2013-001, Regarding Power Operated Relief Valve Inoperable for Greater than Allowed Outage Time Due to Lifted Leads ‎ (← links)
  • 05000251/LER-2010-008, For Turkey Point Unit 4, Regarding Manual Reactor Trip Due to Condenser Tube Leak ‎ (← links)
  • 05000251/LER-2010-007, Regarding Unplanned Entry Into TS 3.0.3 Due to Misalignment of Unit 3 HHSI Pump Discharge Valves ‎ (← links)
  • 05000251/LER-2010-006, Regarding Automatic Reactor Trip Due to Spurious High Pressurizer Pressure Trip Signal ‎ (← links)
  • 05000251/LER-2010-004, Regarding Reactor Trip During Replacement of Degraded Relay in the Reactor Protection System ‎ (← links)
  • 05000251/LER-2010-005, Regarding Failure of Group Step Counter with Valid Manual Actuation of the Reactor Protection System ‎ (← links)
  • 05000251/LER-2010-003, Regarding Damaged Speed Sensor Caused the 4A Emergency Diesel Generator to Be Inoperable ‎ (← links)
  • 05000251/LER-2010-002, Regarding Reactor Trip Resulting from Steam Generator Feedwater Pump Trip ‎ (← links)
  • 05000251/LER-2010-001, Regarding Two Shutdown Bank Rods Were Dropped from Fully Withdrawn Position ‎ (← links)
  • 05000251/LER-2009-001, Regarding 4B Emergency Diesel Generator Inoperable Due to Air-bound Main Fuel Pump ‎ (← links)
  • 05000251/LER-2008-004, Undervoltage Trip Time Delay Relays Cause Loss of Function ‎ (← links)
  • 05000251/LER-2008-003, Class 1 Weld Leak Due to Fatigue and Completion of Technical Specification Required Shutdown ‎ (← links)
  • 05000251/LER-2008-002, Safety Injection Isolated in Mode 3 Due to Inadequate Configuration Control ‎ (← links)
  • 05000251/LER-2008-001, Manual Reactor Trip Due to High Level in the 4A Steam Generator ‎ (← links)
  • 05000251/LER-2006-002, Re Intermediate Range High Flux Trip Setpoint Exceeded Technical Specifications Allowable Value ‎ (← links)
  • 05000251/LER-2006-001, Re Containment Purge Penetration Fails Leak Rate Test Due to Inadequate Preventive Maintenance on Isolation Valve ‎ (← links)
  • 05000251/LER-2005-007, Foreign Material Exclusion Cover Causes Inoperability of One Emergency Diesel Generator ‎ (← links)
  • 05000251/LER-2005-006, Regarding Manual Reactor Trip Due to Rod Control Urgent Failure Alarm ‎ (← links)
  • 05000251/LER-2005-005, Re Loss of Offsite Power Causes Engineered Safety Feature Actuations ‎ (← links)
  • 05000251/LER-2005-004, Re Foreign Material Causes Inoperability of One Emergency Containment Cooler ‎ (← links)
  • 05000251/LER-2005-003, Regarding Incorrectly Wired P-10 Relay Renders One of Two Inputs to P-7 Interlock Inoperable for a Single Train of At-Power Reactor Trips ‎ (← links)
  • 05000251/LER-2005-002, Regarding Automatic Reactor Trip Due to Main Transformer Failure ‎ (← links)
  • 05000251/LER-2005-001, Regarding Steam Generator Feedwater Pump Trip Leading to Manual Reactor Trip and Auxiliary Feedwater Actuation ‎ (← links)
  • 05000251/LER-2004-004, Regarding Manual Reactor Trip Due to Lowering Condenser Vacuum ‎ (← links)
  • 05000251/LER-2004-003, Regarding Bearing Oil Leak Causes High Head Safety Injection Pump to Be Inoperable Longer than Allowed by Technical Specifications ‎ (← links)
  • 05000251/LER-2004-002, Regarding Automatic Reactor Trip Due to Low Steam Generator Level and Steam/Feedwater Flow Mismatch ‎ (← links)
  • 05000251/LER-2004-001, Regarding Inadequate Calibration Renders Radiation Process Effluent Monitor Inoperable ‎ (← links)
  • 05000251/LER-2003-002, Regarding As-Found Cycle 20 Main Steam Safety Valve Setpoint Outside Technical Specification Limits ‎ (← links)
  • 05000251/LER-2003-001, From Turkey Point 4 Regarding Channel Failure of Qualified Safety Parameter Display System ‎ (← links)
  • 05000251/LER-2025-002, Emergency Diesel Generator Actuation ‎ (← links)
  • 05000251/LER-2025-001-01, Degraded Condition ‎ (← links)
  • 05000251/LER-2025-002-01, Emergency Diesel Generator Actuation ‎ (← links)
  • 05000251/LER-2025-003, B Component Cooling Pump and Its Associated Breaker Inoperable ‎ (← links)
  • 05000251/LER-2025-004, Unplanned Reactor Scram ‎ (← links)
• ML081270234 (redirect page) ‎ (← links)
• 05000251/LER-2008-004, Undervoltage Trip Time Delay Relays Cause Loss of Function ‎ (← links)
• 05000250/LER-2008-004, Re Emergency Containment Filter Inoperable Due to Control Circuit Length ‎ (← links)
• 05000251/LER-2008-003, Class 1 Weld Leak Due to Fatigue and Completion of Technical Specification Required Shutdown ‎ (← links)
• 05000250/LER-2008-003, Regarding Inoperable Steam Generator Blowdown Containment Isolation Valve in Excess of Technical Specification Required Isolation Time ‎ (← links)
• 05000251/LER-2008-002, Safety Injection Isolated in Mode 3 Due to Inadequate Configuration Control ‎ (← links)
• 05000250/LER-2008-001, Human Error Causes Grid Disturbance Resulting in Dual Unit Trip ‎ (← links)
• 05000250/LER-2008-002, Containment Purge Valve and Associated Penetration Fail Leak Rate Test Due to Inadequate Preventive Maintenance ‎ (← links)