05000281/LER-1992-003-03, :on 920325,main Cr/Emergency Switchgear Room Chiller Was Declared Inoperable Due to High Svc Water Differential Pressure & Inoperable Emergency Power Source. Svc Water Differential Pressure Restored
05000281/LER-1988-015-02, :on 880626,rod Urgent Failure Annunciator Activated in Control Room.Caused by Failed Circuit Card & Blown Fuse.Failed Circuit Card & Blown Fuse Replaced & Rod Control Sys Tested Satisfactorily
05000280/LER-1988-043, :on 881110,engineering Evaluation Determined That Recirculation Sprays B & C HX Svc Water Inlet Valve & Outlet Valve Have Undersized Motors.Cause Undetermined. Motors Will Be Replaced Prior to Unit Restart
3F0397-01, LER 97-S01-00:on 970130,maint Activities in Circulating Water Sys Resulted in Protected Area Breach.Caused by Failure to Identify Security Function of Plant.Armed Security Was Established
05000272/LER-1995-016-01, :on 950720,difference Between Containment Design Parameters & Accident Analysis Was Discovered.Caused by Inadequate 10CFR50.59 SEs for Changes in Containment Temp Profiles.Changed UFSAR & TS
05000311/LER-1995-004, :on 950607,EFS Actuation Occurred During Unit 2 Controlled Shutdown Per TS 3.0.3.Caused by Inadequate Mgt Oversight of Operability Determination Process.Trained All Licensed Operators
0CAN050202, LER 02-S01-00 for Arkansas Nuclear One Units 1 and 2, Compensatory Measures Were Removed While a Security Perimeter Intrusion Detection Microwave Field Remained Disarmed
05000272/LER-1996-012-01, :on 960723,potential Loss of Residual Capability Identified.Caused by Inadequate Valve Design.Rhr Flow Control Valves Replaced
05000272/LER-1995-020-01, :on 950914,vital 230 Volt MCCs Declared Inoperable Due to Failed Bus Bar Bolting.Caused by Stress Corrosion Cracking.Design Change Package DCP-1ER-0098 Implemented to Replace Bus Bolts W/Carbon Steel Bolts
05000260/LER-1994-010, :on 941005,loss of ECCS Division II Instrumentation Resulting from Blown Fuse in Atu Inverter. Caused by a Failed Capacitor.Blown DC Input Fuse Was Replaced
05000260/LER-1996-008, :on 961101,Unit 2 Main Steam SRV Pilot Cartridges Failed Setpoint Tolerence Bench Tests.Caused by SRV Pilot Disc/Seat Bonding Resulting in SRV Setpoints.Srv Pilot Cartridges Replaced
05000316/LER-2020-004-01, Regarding Unit 2 Automatic Reactor Trip on Low-Low 24 Steam Generator Water Level
05000315/LER-2020-001, Containment Closure Requirements Not Met During Refueling Operations
05000369/LER-2020-001, Condition Prohibited by Technical Specification 3.4.15, Reactor Coolant System (RCS) Leakage Detection Instrumentation
05000458/LER-2020-004, Inadvertent Initiation and Injection of High Pressure Core Spray (HPCS)
05000301/LER-1998-004-01, :on 980424,operations W/Reactor Core Power Level Was in Excess of 1518.5 Mwt.Caused by Failure to Return FT-466V Input Parameter to Off Scan.Input FT-446V Was Removed from on Scan at Approx 1452
05000260/LER-1989-019, :890623,loop II of RHR Sys Technically Inoperable When Operability Required by Tech Specs.Caused by Inadequate Tracking & Dispositioning of Test Deficiency. Signature Requirements Added to Test Packages
05000318/LER-1989-005-01, :on 890323,discovered That Snubber Functional Test Procedure to Satisfy Tech Specs 4.7.8.1.c & D Not Adequate.Caused by Lack of Adequate Control for Procedures. Rev Proposed to Facility Instruction CCI-104
05000445/LER-1998-005, :on 980617,functional Requirements of Hps Was Not IAW Design.Caused by Failure to Completely Evaluate FSAR Impact on Design Basis.Developed post-accident Recovery Guidance & Design Mod to Allow Use of 12 Inch Inlet Valve
05000317/LER-1987-014, :on 871016,containment Air Lock Door Seal Functional Test Not Performed within 72 H After Use.Caused by Administrative Oversight.Appropriate Employees Will Be Counseled
05000266/LER-1998-008, :on 980203,EDG Air Start Motor Solenoid Valves W/Spring Not in Accordance W/Design Occurred.Caused by Use of 275 Psig Solenoid Valve Which Does Not Meet Minimum DC Voltage Available.Solenoid Valves Modified
05000382/LER-1998-004, :on 980304,TS 4.0.3 Condition - CPC Channel Functional Test,Was Concluded from Preliminary CEOG Rept. Caused by Human Error.Cpc Channels A,B & C Were Satisfactorily Tested
05000324/LER-1999-008-02, :on 990920,condenser Pressure Sensing Line Drain Activities Resulted in ESF & RPS Actuation.Caused by Inadequate Implementation of C/A to Previously Identified Condition.Procedures Were Revised.With
05000327/LER-1986-030, :on 860717,three Tech Spec Surveillance Requirements Not Performed.Caused by Procedure Inadequacy & Deficiency in Initial Writing of Section of Tech Spec.Tech Spec Change Will Be Submitted
05000335/LER-1987-002-02, :on 870207,reactor Tripped on Low Steam Generator Level During Controlled Shutdown for Scheduled Refueling Outage.Caused by Equipment Failure.Steam Generator Level Indicators Repaired
05000346/LER-1986-028, :on 860710,review of B&W Small Break LOCA Licensing Analyses Identified Potentially Nonconservative Input Assumptions.Caused by Lack of Util Involvement in B&W Analyses Performed in 1972 & 1973
05000298/LER-1997-013, :on 960807,plant Was Noted Outside Design Basis Due to Inadequate Scram Discharge Volume Mod.Inadequate Design Review May Have Caused Condition.Cause Is Unknown. Implemented Mod MP96-121 in May 1997
05000440/LER-1997-011, :on 970921,TS Surveillance Test Performance Resulted in Esfas.Caused by Procedure Weakness.Temporarily Revised SVI-B21-T2010 & SVI-B21-T2202 to Allow Completion of Instrument Check Valve Testing
05000289/LER-1999-001-01, :on 990122,short Sections of Piping Caused by Misplacement of Sensing Elements & Insulation.Caused by Failure to Adhere to Vendor instruction.Re-installed Heat Trace Sys
05000324/LER-1999-002-02, :on 990329,reactor Tripped.Caused by Failed Electrical Connections on Vibration Detector for Number 9 Main Turbine Bearing.Vibration Detectors for Main Turbine Number 9 Bearing Replaced.With
05000324/LER-1999-001-02, :on 990317,RCIC Sys Declared Inoperable.Caused by Inadequate Packing Compression on live-load Packing.Valve 2-E51-F008 Repacked & Tested in Accordance with Plant Procedures.With
05000289/LER-1999-002, :on 990212,potential Failure of Multiple Containment Monitoring Sys CIV (CM-V-1,2,3 & 4) Was Noted. Caused by Inappropriate Use of Vendor Info.Personnel Will Be Trained on Mgt Expectations.With
05000302/LER-1998-015, :on 981203,raw Water Pumps Were Declared Inoperable Resulting in Entry Into ITS 3.0.3.Caused by Check Valve Failure.Valve Was Repaired & Placed Back Into Service. with
05000327/LER-1998-004-02, :on 981120,failure to Perform Surveillance within Required Time Interval,Was Determined.Caused by Leaking Vent Valve.Engineering Personnel Evaluated Alternative Methods for Performing Channel Check
05000412/LER-1998-014-01, :on 981112,inadequate Source Range High Voltage Setpoint Led to Failure to Comply with Tss.Caused by Human Error.High Voltage Setpoint for Source Range N32 Was Adjusted to 1600 Vdc IAW W Technical Info.With
05000348/LER-1998-004-03, :on 980909,turbine Trip & Consequent Reactor Trip Occurred.Caused by Reactor Protection Sys Card Failure. Failed Card Was Replaced & Unit 1 Returned to Power on 980910.With
05000354/LER-1998-005-03, :on 980810,discovered That Two Nitrogen Gas Supply Check Valves to B hydrogen-oxygen Analyzer Were Not Being Tested.Caused by Missed Ist.Ist Data Base Is Being Reviewed to Assure Completeness & Accuracy.With
05000301/LER-1997-002-01, :on 970415,potential Reactor Coolant Sys Branch Connection Stresses Beyond Design Basis,Indicated.Caused by Mod Initiated to Remove RTD Bypass Line Isolation Valves. Stress Analysis Conducted on RTD Bypass Piping
05000315/LER-1985-043, :Corrective Actions & Preventive Measures Taken Re Discrepancies in Process Sensor Calibr Completed,Per Confirmatory Action Ltr Issued on 850820
05000266/LER-1997-023, :on 970508,discovered Noncompliant Emergency Lighting for Postulated App R Fires.Caused by Alternative Provisions Made in Original Safe Shutdown Analysis.Emergency Lights Will Be Installed
05000461/LER-1997-008, :on 920408,determined That DG Undervoltage Relays Inoperable Due to Inadequate Process to Review Operability Requirements of Plant Equipment as Defined in Ts.Amend Requested to Change TS
05000295/LER-1985-019-01, :on 850607,reactor Tripped & MSIVs Closed.Trip Caused by Removal of Source Range Fuses During Troubleshooting & Closure Caused by Failure of Summator. Module Replaced
05000305/LER-1996-007, :on 961023,identified Design Deficiency in Containment Isolation Function.Caused by Oversight During Plant Design.Implemented Administrative Controls to Preclude Subject Condition Prior to Plant start-up
05000443/LER-1997-001, :on 970109,identified That Certain Obstructions to Flow of Flood Water Off Site May Produce Flood Levels Exceeding Elevations Specified in Fsar.Caused by Misapplication of Design Inputs
05000285/LER-1996-008, :on 961011,ventilation Isolation Actuation Signal Occurred.Due to High Containment Activity.Plant Procedures Will Be Reviewed & Revised
05000395/LER-1996-010, :on 961202,missed Surveillance on Slave Relay Occurred.Caused by Personnel Oversight in Not Individually Tasking Each Surveillance Contained in Stps.Review Will Be Completed by 970228
05000333/LER-1996-013-01, :on 961116,reactor Protection & Primary Containment Isolation Sys Actuation on False Low Reactor Water Level Occurred Due to Personnel Error.Instrument Surveillance Procedure Changed
05000285/LER-1996-012, :on 961111,potential for Vaporizing Cooling Water in Containment Fan Cooling Units Occurred.Caused by Loop Coincident with Loca.Analyses Have Been Performed
05000325/LER-1996-015, :on 961019,determined Suppression Chamber Water Level Operating Range of -27 to -31 Inches Required by TS 3.6.2.1 Was Not Equivalent to Water Vols.Caused by Inadequate Calculations.Controls Established
05000410/LER-2020-001, Manual Scram Due to an Electro Hydraulic Control Fluid Leak on the Turbine Control System
05000266/LER-1996-006, :on 960813,emergency Power Out of Service Coincident with Opposite Train SW Pump.Root Cause Evaluation Being Performed.C/As Will Be Determined as Necessary from Results of Root Cause Evaluation
05000289/LER-1995-005, :on 951012,invalid Heat Sink Protection Sys Actuation Occurred.Caused by Failure of Two Logic Modules. Continued Daily Inspections of Hsps Cabinet Lamps & Counseled Personnel Re Communication Technique
05000302/LER-1996-011, :on 960412,identified Circuits Not Being Appropriately Tested Per Improved Ts.Caused by Human Error. Applicable Surveillance Procedure Revised to Incorporate Testing of ESFAS Logic for Circuits
05000382/LER-1996-006-01, :on 960517,reactor Trip Occurred.Caused by Failed Component & Original Design Inadequacies.Replaced Both Motor/Generator (M/G) Set Overvoltage Relays & Replaced a M/G Set Voltage Regulator
05000382/LER-1996-007-01, :on 960411,discovered That Design Basis Flow Rates Could Not Be Achieved on Auxiliary Component Cooling Water Sys.Caused by Inadequate Design.Modified Sys Design & Reviewed Other safety-related Fluid Systems
05000285/LER-1996-004, :on 960315,discovered Adequate Shutdown Margin Was Not Maintained.Caused by Inadequate Technical Review by Plant Personnel Involved in Reviewing Procedure Change. Appropriate Personnel Trained on Incident
05000423/LER-1995-020, :on 951202,RCS Pressure Boundary Leak from Valve Bonnet Stem leak-off Pipe Occurred.Caused by Crack Near Toe of Fillet Weld Between Pipe & Valve Body.Removed Pipe & Valve Bonnet Weld
05000382/LER-1996-003-01, :on 960130,logarithmic Power Channels Indicated 5 Percent of Scale Below Actual Power.Caused by Not Periodically cross-correlating Log Power to Linear Power. Recalibrated Log Power Channels
05000301/LER-1995-006-01, :on 951125,PORV post-maint Testing Was Not Performed Prior to Establishing Ltop.Caused by Inadequate Control of post-maint Testing.Established TS Compliance by Venting RCS
05000301/LER-1995-005-01, :on 951025,plugged 46 Tubes Due to Degradation in Roll Transition,Tubesheet Crevice & Tube Support Plate Regions.Performed Closeout Insps Following Maint of Each Sg
05000354/LER-1995-025-01, :on 951024,HPCI Sys Was Declared Inoperable Due to Out of Adjustment Limit Switch.Replaced Limit Switch & Repaired HPCI Turbine Steam Admission Valve
05000328/LER-1995-006-02, :on 951001,failed to Maintain Two Qualified Offsite Power Sources Due to Inadequate Training.Will Provide Licensed Operator Training
05000325/LER-1995-002-01, :on 950323,found Multiple Cl Sensors Used for Control Bldg Isolation Logic to Be Outside TS Tolerances During Routine Calibr.Caused by Design Deficiency. Re-evaluated Design Changes to Maintain Control Bldg Sensor
05000285/LER-1994-011, :on 941228,SR for SG Level Check Was Unsatisfied.Caused by Inadequate Review.Dept Personnel Trained on Event
05000458/LER-1994-032, :on 941214,Division III DG Failed Due to Improper Synchronization Attempt by Operator.Considered Disciplinary Action for Individual Involved & Continued Performance That Monitored Testing of DG
05000458/LER-1994-023, :on 940908,reactor Scrammed Due to Spurious Signals from Undamped Rosemount Model 1153 Transmitters. Conditions Leading to Failure Determinded to Be Reportable Per 10CFR21.Model 1153 Transmitters Replaced
05000483/LER-1994-003, :on 940708,QA Engineer Surveillance of Radiation Monitors Indicated Utility Engineering Evaluation Conflicted W/Fsar Chapter 7.5.Caused by Utility Personnel Not Aware of Surveillance Procedures
05000454/LER-1994-004-09, :on 940423,discovered That Oc Waste Gas Decay Had Not Been Sampled After Radioactive Matls Added.Caused by Poor Work Practices & Inadequate Training.Corrective Action:Personnel Retrained
05000317/LER-1994-003, :on 940321,noticed Leakage from Rcs.Caused by Pwscc.Corrective Action:Sleeve Location B-3 & FF-1 Have Been Plugged W/Alloy 690 Plug Welded to Outer Diameter of Pzr Lower Head
05000331/LER-1994-003, :on 940124,determined That TS Table 3.2-A Action Statement for Off Gas Vent RMs Not Complied W/During Routine Maint on 940119 Due to Improperly Prepared Work Document.License Amend Process Revised
05000454/LER-1994-002-09, :on 940309,main Steam Safety Valves Setpoints Found Out of Tolerance Due to Calculation Error.Amend to TSs to Allow Tolerance of +3% Requested.Valve Setpoints Will Be Retested by 940509
05000317/LER-1993-007-01, :on 931229,performance Test Indicated Possibility of SRW Heat Exchanger Inoperability.Caused by Original Design Calculations Assuming Min SRW Flow Was Not Limiting Case.Hxs Determined Operable
05000293/LER-1993-015, :on 930630,HPCI Sys Declared Inoperable Due to Indicated Flow During Surveillance.Caused by Foreign Matl That Plugged Portion of Restricting Orifice.Restricting Orifice Removed,Cleaned & Reinstalled
05000293/LER-1993-010, :on 930519,SUT Became de-energized During Planned Calibr of Turbine/Generator Relays Lockout Test While Shut Down.Caused by Personnel Error.Discussion Conducted W/Personnel Re Attention to Detail
05000410/LER-2019-001, High Pressure Core Spray Declared Inoperable
05000334/LER-1989-014-01, :on 891108,routine Radiation Barrier Check Identified Faulty Door Locking Mechanism on North Door to East Valve Trench Area.Caused by Welded Latching Mechanism. Locking Mechanism Modified
05000425/LER-2019-002, Microswitch Failure Causes Closure of Main Steam Isolation Valve and Subsequent Automatic Reactor Trip
05000364/LER-2019-002, Manual Reactor Trip Due to Misaligned Rod During Low Power Physics Testing
05000280/LER-1992-006-03, :on 920419,filter Exhaust Fan 1-VS-F-58B Tripped Due to Excessive Vacuum.Caused by Auxiliary Ventilation Exhaust Filter Sys Train B Filters Being Near End of Svc Life.Fan Was Restarted
05000281/LER-1991-010-03, :on 911031,determined That Damage to C Main Steam Trip Valve/Bypass Valve 2-MS-155 Rendered Valve Incapable of Immediate Closure.Caused by Failure of Yolk Bushing Threads in Valve.Valve Closed
05000281/LER-1992-004-02, :on 920326,B Chiller Became Inoperable Due to Hand Operated Rocker Switch Inadvertently Being Placed in Off Position.Chiller Returned to Svc.Upgrade to Sys Will Include Installation of Two Chillers
05000280/LER-1989-042, :on 891031,leak Detected Through Crack in Fillet Weld on Socket Tee Connecting Drain Line to Letdown Line Which Exceeded Allowable Type C Leakage.Caused by Vibration.Line & Valve Configuration Changed
05000281/LER-1988-001, :on 880127,discovered That Leakage Through Containment Isolation Valves TV-SS-201A & TV-SS-201B Greater than ASME Section XI Spec.On 880202,wrong Leads Lifted for Trip Valves.Caused by Impurities in Sys
05000280/LER-1988-046, :on 881231,alarm Received in Control Room Indicating That Valve 1-SW-263 Had Closed.Caused by Personnel Error.Operators Verified That No Fire Existed in Room 3.Valve Opened & Chiller C Restarted
05000281/LER-1989-001-02, :on 890105,loss of Containment Integrity Occurred During Refueling Operations.Caused by Loss of Administrative Controls Due to Procedural Deficiencies. Refueling Integrity Procedures Modified
05000280/LER-1988-035, :on 880914,specific Activity Sample of Reactor Coolant Showed Dose Equivalent I-131 Level of 1.04 Microcuries/Cc,Exceeding Tech Spec Limits.Caused by Iodine Spike Due to Fuel Element Defects
05000281/LER-1995-003, :on 950224, as Found Calibration Test Data for Three RPS Transmitters Not within Allowable Tolerance. Caused by Faulty Pressure Gauge Used in Calibration.Pressure Gauge Replaced & Repeated Calibration Check
05000280/LER-1995-008, :on 950919,pressurizer Safety Valve Found Setpoint Out of Tolerance.Caused by Psvs Being Installed Prior to Start of Most Recent Operating Cycle
05000280/LER-1996-001, :on 951213,ESW Pump Was Inoperable Due to Loss of Missile Protection for Piping.Revised DCP 91-025
05000280/LER-1997-005, :on 970502,Unit 1 Power Range Nuclear Instrumentation Was Inoperable Due to Personnel Error.Sro & STA That Were Involved in Event Were Counseled
05000280/LER-1996-003-02, :on 960513,control Room Air Handling Units (AHU) Declared Inoperable.Caused by Mechanical Failure. Adjusted 1-VS-AC-2 Backdraft Dampers Counterweight Arm for AHU 1-VS-AC-2
05000281/LER-1988-009-02, :on 880420,component Cooling Water HXs Declared Inoperable.Caused by Vacuum Priming Lines Up to Isolation Valves Not Being Seismically Supported.Engineering Work Request to Install Seismic Supports Made
05000280/LER-1988-014-01, :on 870630,determined That Unique Scenario Could Exist Whereby Auxiliary Feedwater Could Be Lost to Operating Unit.Administrative Controls Established & Safety Analysis Reviewed for high-energy Line Break
05000280/LER-1988-011-01, :on 880415,power-operated Relief Valves Failed to Manually Open When Selector Switches Placed in Open Position.Cause Under Investigation.Selector Switches,Air Supply & Valves Examined for Malfunctions
05000280/LER-1988-029, :on 880815,reactor Trip & Safety Injection Occurred.Caused by Spurious Initiation of Train a High Consequence Limiting Safeguard.Relay Replaced & Limit Switch on Steam Dump Valve Adjusted
05000281/LER-1988-002-02, :on 880202,containment Isolation Valves Declared Inoperable Due to Leakage in Excess of Spec Value. Cause Not Determined.Valves Will Be Replaced/Repaired Based Upon Failure Analysis Results
05000280/LER-1988-024, :on 880711,16 Individual Rod Position Indicators for Eight Rods in Each Shutdown Bank a & B Differed from Group Demand Step Counter by Greater than 12 Steps.Caused by Drift in Subj Indicators
05000280/LER-1987-027, :on 871027,electrical Short in Train a Turbine Bldg Flood Control Panel Caused Spurious Completion of Flood Protection Circuit.Caused by Leak on Access Manway of Moisture Separator Reheater 1-MS-E-1B
05000280/LER-1988-017-01, :on 880606,discovered Debris in Temporary Discharge Cone Strainer & Recirculation Spray Sump Pumps. Caused by Inadequate Insp Program.Containment Sump & Pump Screen Surveillance Will Be Implemented
05000281/LER-1987-005-03, :on 871014 Electrician Inadvertently Completed Flood Protection Circuit Causing Two of Four Condenser Circulating Water Inlet Valves to Close.Caused by Personnel Error.Procedure Written for Maint Personnel
05000281/LER-1986-018, :on 861112,discovered Environ Qualified Components Not Installed Per Approved Raychem Guidelines. Caused by Inadequate Training of Personnel Installing Matl. Procedures Revised & Addl Training Conducted
05000280/LER-1987-022, :on 870830 & 0903,main Control Room Ventilation Isolation Occurred.Caused by High Voltage Output on Chlorine Gas Detector.Chemistry Dept Verified That No Chlorine in Main Control Room.Ventilation Sys Realigned
05000280/LER-1988-009-01, :on 880311,specific Activity Sample of Reactor Coolant Showed dose-equivalent I-131 Level of 1.5 Uci Which Exceed Tech Spec Limit.Caused by Fuel Element Defect in Reactor Core
05000280/LER-1987-015-01, :on 870717,individual Rod Position Indicators for Shutdown Banks a & B & Control Banks A,B,C & D Declared Inoperable.Caused by Banks Indicating Below Demand Counter Position Due to Dirty Dc Power Contacts
05000272/LER-1997-001-02, :on 970117,discovered Inadequate IST Surveillance of B Injection Inlet Valves.Caused by Inadequate Communication Between EOP & Ist.Reviewed Salem EOPs for Similar Problems
05000311/LER-1996-015-02, :on 961219,breach of Containment Closure During Core Reload Occurred.Caused by Inadequate Inplementation of Outage Scheduling & Risk Management Requirements.Containment Closure Was Reestablished Using Alternate Isolation Poi
05000272/LER-1997-008, :on 970321,inadequate Surveillance Testing of PORV Accumulators & Check Valves Was Attributed to Lack of Adequate Controls for Development & Maintenance of TS Surveillance Procedures.New Procedure Made
05000272/LER-1996-041, :on 961228,surveillance for Radiation Monitors Source Check Required by TS Was Missed.Caused by Lack of Attention to Detail.Reemphasized Mgt Expectations Concerning Surveillance Test Accountability
05000272/LER-1994-015, :on 941018,determined That Refueling Water Storage Tank Volume Was Less than Required.Cause Not Determined.Properly Adjusted Transmitters & Returned RWST Level to Specification
05000311/LER-1995-008-02, :on 951215,Tech Spec 4.9.9 Missed Isolation Testing Discovered.Caused by Lack of Adequate Controls to Ensure All Testing Requirements Addressed.Procedure S2.IC-FT.RM--0088(Q) Revised
05000272/LER-1996-002, :on 960110,evaluation Determined That Motor Operated Gate Valves Susceptible to Pressure Locking & Thermal Binding.Caused by Inability to Meet GL 95-07 Criteria.Test Procedure Changed
05000255/LER-1996-004, :on 960118,SIS Disabled W/Primary Coolant Sys Greater than 300 F.Caused by Personnel Error.Permanent Maint Procedure to Disable/Enable SIS Actuation on Low Pressurizer Pressure Will Be Revised to Align W/Ts
05000255/LER-1995-001-01, :on 950302,left Channel DBA Sequencer Malfunctioned & Started Most of Left Channel Safeguards Equipment.Caused by Failure of DBA Sequencer micro-processor Module.Svc of Mfg of Sequencer Hardware Will Be Utilized
05000255/LER-1987-013, :on 870322,personnel Identified That Water Flow Switch Fire Detector WFS-262 (Kp;Fis) Inoperable.Caused by Failure to Perform 1 H Fire Watch.Quarterly Test Revised to Include Refs to Appropriate Tech Specs
05000255/LER-1987-014, :on 870427,primary Data Logger Computer Memory Failed Causing in-core Alarm Sys to Be Inoperable.Caused by Operator Misinterpreting Tech Spec Action Statement.Tech Spec Revised
05000296/LER-1996-004, :on 960717,loss of ECCS Division I & Division II Instrumentation Renders ECCS Equipment Inoperable.Caused by Loss of Inverter Output.Failed Components Replaced in Atu Inverter Circuitry & Instrumentation Logic Restored
05000296/LER-1997-004-02, :on 970414,unplanned Manual Start of EDG During Scheduled Redundant Start Test Occurred.Caused by Personnel Error.Edg 3D Shutdown & Returned to pre-event Configuration
05000296/LER-1997-001-04, :on 970305,loss of Offsite Power on Unit 3 During Refueling Outage Resulted from Shorted Component. Replaced Relays Involved in Event W/Less Sensitive Relays
05000260/LER-1996-004-01, :on 960425,Unit 2 SRV Pilot Cartridges Failed Setpoint Acceptance Tests.Caused by SRV Pilot Disc/Seat Bonding Resulting in SRV Setpoints Deviating.Valves Currently Being Retested & Recertified
05000296/LER-1997-002-03, :on 970410,HPCI Declared Inoperable.Caused by Personnel Error.Operations Personnel Stopped Instrument Mechanics Testing & Returned HPCI to Standby Readiness
05000296/LER-1996-006-03, :on 961106,loss of ECCS Div 1 Instrumentation Rendered ECCS Equipment Inoperable.Caused by Cleared Fuse in ECCS Div.Fuse Replaced & Addl Testing to Challenge Replacement Fuse Performed
05000400/LER-1987-018, :on 870403,manual Reactor Trip Initiated Due to Loss of Both Main Feedwater Pumps.Caused by Inadvertent Short of Test Leads in Process Instrumentation Cabinet & Incorrect Setpoint.Undocumented Leads Removed
05000400/LER-1987-020, :on 870413,reactor Trip Setpoints on All Three Overtemp Delta Temp (Odt) Bistables Incorrectly Set.Caused by Apparent Design Oversight in Odt Circuit Design & Vendor Testing Methodology.Test Procedures Revised
05000400/LER-1996-007, :on 960425,failed to Perform Tech Spec Surveillance Testing Per Specification 4.7.6.d.3.Caused by Inadequate Procedure Development.Satisfied Differential Pressure Testing Requirement
05000400/LER-1996-004, :on 960205,RWST Level Transmitters Failed & Violation of TS Action Statement Occurred.Caused by Freezing of Level Transmitter Sensing Lines.Frozen Lines Thawed & Missing Insulation Replaced
05000400/LER-1992-005-02, :on 920527,WRGM Declared Inoperable & Removed from Svc Due to Personnel Error.Additional Training Provided for Personnel Involved
05000400/LER-1991-021-01, :on 911218,error Discovered in Program Utilized to Determine Containment Sump in-leakage Flow Rate.Caused by Personnel Error During Computer Design Development.Erroneous Error Corrected & Event Reviewed
05000400/LER-1990-024, :on 901121,64 Bussman Fnm Type Fuses in 125- Volt safety-related Applications Found Unacceptable.Caused by Recent Downgrade in Fuse Performance Specs Provided by Vendor.Fuses Replaced,Per Plant Mod PCR-5549
05000400/LER-1989-017-01, On 891009,generator & Main Power Transformer Phase Differential Relay Tripped Lockout Relay.Caused by Multiple Ground Faults.Design Changes & Repairs Being Conducted While Plant Performs Refueling
05000400/LER-1990-010, :on 900405,control of Reactor Auxiliary Bldg Emergency Exhaust Pressure Boundary Not Implemented.Caused by Lack of Administrative Controls for Doors & Hatches. Administrative Controls Implemented
05000400/LER-1989-014-01, :on 890821,determined That Two Accessible Discharge Piping High Point Vents Not Verified Full of Water at Least Once Per 31 Days.Caused by Procedural Deficiency. Vents Verified Free of Air & Procedure Revised
05000400/LER-1988-033, :on 881125 & 1202,declared Charging Safety Injection Pump (Csip) Inoperable.Caused by 1C Csip Scantily Covered in ESF Response Surveillance Test Procedures.Test to Verify 1C Csip Response Time Completed
05000400/LER-1987-034, :on 870611,air Leakage by Inner & Outer Doors of Personnel Air Lock Excessive.Caused by Flat Spots on O-ring Seal.Seals on Inner & Outer Doors Replaced & Procedure OMM-001 Revised
05000400/LER-1987-037, :on 870621,manual Reactor Trip Initiated from 30% Power After Operating Main Feedwater Train Tripped. Caused by Failed Open Feedwater Pump Recirculation Valve. Circuit Repaired & Plant Returned to Svc
05000400/LER-1987-039, :on 870619,intermediate Range (IR) High Neutron Flux Trip Setpoint Found Out of Calibr.Caused by Previous Adjustment to IR Setpoints.New Scaling Currents for 25% Trip Incorporated Into Applicable Procedures
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
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
05000250/LER-1988-007, :on 880427,3A Intake Cooling Water (Icw) Pump out-of-svc Due to Discharge Pressure Gauge Piping Failure. Caused by Corrosion of Coupling Attaching Pressure Gauge Piping to Icw Discharge Pipe.Piping Repaired
05000316/LER-1987-008-01, :on 870722,ESF Actuation Occurred Due to Extreme High Level in Steam Generator 24.Caused by Erratic Response of Main Feedwater Pump Delta P Controller. Plant Procedures Implemented
05000315/LER-1995-010, :on 951020,inadequate Communication Resulted in Unexpected ESF Actuation.Completed Repairs to 1NRI-36 & Declared Detector Operable
05000316/LER-1993-004, :on 930408,rod Position Indication for Rods H-12 & M-8 Found Indicating Greater than 12 Steps from Demand Position Indication.Caused by Transformer Sensitivity to Temp Changes.Position Verified
05000315/LER-1992-006-02, :on 920618 & 19,10 of 20 Main Steam Safety Valve Lift Settings Found Outside of TS Tolerances.Caused by Setpoint Drift.Valves Reset to Acceptable Values & Retested Satisfactorily
05000316/LER-1992-003, :on 920219,20 & 21,7 of 20 Main Steam Safety Valve Lift Setting Found Outside of TS Established Limits. Caused by Setpoint Drift.Setpoint Ranges Reset & Maint Procedure for Valve Repair Revised
05000315/LER-1992-002, :on 920210,AB EDG Tripped on Overspeed While Starting for Routine Operability Test.Caused by Sluggish Governor Operation.Design Change Has Been Initiated to Modify Ventiliation Supply Damper Linkage
05000315/LER-1991-004-01, :on 910512,while Performing Main Generator Max Reactive Capability Test,Rps (Reactor Trip Sequence) Occurred.Caused by Undervoltage Condition Sensed on RCP Busses.Defective Component Replaced
05000315/LER-1991-002, :on 910128,emergency Diesel Generator Removed from Svc & Declared Inoperable W/O Meeting TS Surveillance Requirements within 1 H.Caused by Personnel Error.Lessons Learned Re Event Reviewed W/Operators
05000316/LER-1990-001, :on 900112,unplanned ESF Actuation Occurred During Calibr of Time Delay Relays for Degraded Voltage. Caused by Lack of Insulation on Wiring.Personnel Instructed to Disable Circuit by Method of Knife Switch
05000316/LER-1989-002, :on 890116,seismic Restraint,Located on 24-inch ECCS Suction Line,Noted to Have Significant Deformation. Probably Caused by Removal & Reinstallation of Piping During Startup.Mod Initiated to Repair Restraint
05000315/LER-1988-007-01, :on 880908,flow Passage Insp of Ice Condenser Revealed Frost & Ice Buildup.Caused by Sublimation of Ice or High Humidity in Containment Air.Flow Passages Manually Cleaned to Remove Accessible Frost
05000315/LER-1988-012, :on 881111,turbine Room Sump Not Sampled & Analyzed in Accordance W/Tech Specs.Caused by Personnel Error.Procedures Updated to List Required Sampling Frequencies & Analysis for Sys
05000315/LER-1987-022, :on 871007,as Found Data of Two Pressurizer Level Channels Exceeded Tech Spec Limiting Condition for Operation.Caused by Transmitter Calibr Shift.Calibr Checks for New Transmitter Installations Planned
05000315/LER-1988-010-01, :on 881004,unit Electrical Cables of Reactor Head Vent Valves & Pressurizer Steam Space Vent Valves Determined Not Physically Configured Per Design Drawings. Configuration Discrepancies Corrected
05000316/LER-1988-004, :on 880420,discovered Six of Twenty Main Steam Safety Valves Lift Setpoints Out of Spec During Surveillance Testing.Caused by Testing Method & Setpoint Drift.Safety Valves Setpoints Reset
05000315/LER-1987-021, :on 871013,ESF Actuation Occurred Due to Feedwater Flow/Steam Mismatch Coincident W/Low Level on Steam Generator 11.Caused by Failure of East Main Feedwater Pump Shaft Driven Oil Pump.Bearings Replaced
05000315/LER-1987-016, :on 870815,discovered That Boron Injection Sys Distribution Flow Not in Compliance W/Tech Spec Requirements.Caused by Normal Sys Fluctuations Combined W/ Instrument/Measurement Error.Flow Reconciled
05000316/LER-1987-006-01, :on 870615,containment Spray Pumps Declared Inoperable Due to Improperly Performed Tech Spec Surveillances Testing.Caused by Improper Labeling of Flow Instrumentation Being Maintained.Pumps Tested
05000315/LER-1987-013, :on 870701 & 02,ice Buildup Discovered in Ice Condenser Flow Passages.Caused Possibly by Sublimation of Ice or High Humidity in Containment Air.Condenser Defrosted & Matter Discussed W/Utils That Have Same Unit
05000335/LER-1997-011, :on 971102,non-conservative RAS Set Point Resulted in Operation Prohibited by Ts.Caused by Inadequate Set Point & Instrument Loop Scaling Process.Revised ESFAS Functional Tp W/Proper Set Point
05000528/LER-1990-006-02, :on 900814,reactor Trip Occurred Following Manual Turbine Trip & Phase B of Main Transformer Loosing Forced Cooling.Caused by Failure of Control Power Transformer.Transformer Replaced
05000530/LER-1989-001, :on 890303,electrical Grid Disturbance Resulted in Main Generator Output Breakers Opening,Resulting in Reactor Power Cutback & Steam Bypass Control Sys Actuation. Caused by Malfunction in Subj Control Sys
05000528/LER-1989-019, :on 890929,Train B of Fuel Bldg Essential Ventilation Actuation Sys Spuriously Actuated.Caused by Loose Connection Between Radiation Monitor Remote Indication & Control Unit Instrument Drawer & Cabinet
05000530/LER-1989-013-01, :on 890926,control Room Operator Inadvertently Turned Wrong Handswitch During post-maint Testing Which Resulted in ESFAS Actuation.Caused by Personnel Error. Disciplinary Measures Taken
05000528/LER-1989-006-01, :on 890731,containment Purge Isolation Actuation Signal Initiated Due to Loss of Power to Panel 1E-PNB-D26.Cause Not Identified.Power Restored & Radiation Monitor RU-38 Placed Back on Line
05000528/LER-1988-006, :on 880321,determined That Allowable Surveillance Test Interval Had Been Exceeded for Incore Detector Sys.Caused by Personnel Error & Inadequate Programmatic Controls.Personnel Counseled
05000528/LER-1991-001, :on 910110.determined That Postulated Break in Reactor Coolant Pump High Pressure Seal Cooler Could Result in RCS Leak Outside Containment.Caused by Tube Rupture in Seal Cooler.Rcs Activity Monitored
05000529/LER-1990-004, :on 900504,discovered That Pressurizer Code Safety Valves as-found Setpoints Out of Tolerance.Caused by Performance Limitation of Pressurizer Safety Valves.Valves Adjusted & Retested Satisfactorily
05000528/LER-1989-017, :on 891023,four Unsealed Penetrations in Unit 3 Seismic Gap Area Discovered During Visual Insp of 94 Ft Elevation Diesel Bldg Pipe Trenches.Fire Watches Established in All Units.Sealing of Penetrations Underway
05000529/LER-1989-008-01, :on 890509,calculational Error Identified in Surveillance Test That Would Have Resulted in Boron Diluted Alarm Channel 2 Being Inoperable.Caused by Personnel Error. Technicians Counseled & Test Procedure Revised
05000397/LER-1991-028, :on on 910930,containment Airlock Door Seal Leakage Test Not Performed within Allowable Surveillance Interval.Caused by Inadequate Personnel Work Practices. Master Startup Checklist Amended
05000397/LER-1991-022, :on 910905,inboard RHR Sys Shutdown Cooling Supply Valve Automatically Isolated on High Suction Line Flow Signal.Caused by Instrumentation Drift.Sys Realigned & Loop B Placed Back in Svc
05000397/LER-1991-021, :on 910801,determined That Tritium Sampling Was Not Being Performed During Startup,Shutdown & 15 Percent Power Change Evolutions.Caused by Inadequate Procedure/ Procedure Review.Changed Procedure
05000397/LER-1991-030, :on 911104,small Leak Noted in Welded Connection Between RHR Sys Drain Valve & RHR Loop a Shutdown Cooling Return Valve.Caused by Const Fabrication Defect.Rhr Valve V-161A Isolated from RCS
05000397/LER-1991-013, :on 910507,non-compliances W/Tech Specs Identified as Part of Program of Surveillance Procedure Verification.Further Evaluation Performed.Quality Action Team to Be Chartered to Evaluate Program
05000397/LER-1991-012, :on 910506,manual Initiation of Reactor Protection Sys Occurred Due to Low Scram Air Header Pressure.Caused by Hose Failure.Hose Replaced
05000397/LER-1990-029, :on 901108,inadequate Containment Penetration Testing Associated W/Wetwell Hatch Pressure Warning Devices Discovered
05000397/LER-1990-020, :on 900917,util Determined Overheating of Control Cabinet Could Cause Diesel Generator Failure
05000397/LER-1990-012, :on 900527,failure of Diesel Generator Slip Ring End Bearing Resulted in Fire in Bearing Area.Caused by Mfg Error,Design Deficiency & Personnel Error.Emergency Operating Procedures Used to Deal W/Fire
05000397/LER-1990-003, :on 900126,HPCS Sys Pump Suction Valve Switchover Occurred During Performance of Procedure for Draining Ref Leg.Caused by Plant Configuration.Sys Restored to pre-event Lineup Status
05000397/LER-1990-014, :on 900703,HPCS Sys Pump Suction Switchover from Condensate Storage Tanks to Suppression Pool Occurred Due to Suppression Pool High Water Level Condition.Caused by Procedural Inadequacy.Procedures Modified
05000397/LER-1990-002, :on 900118,discovered That Main Steam Solenoid Pilot Valves Inoperable from June 1986 to June 1989.Caused by Personnel Error Due to Installation of Unqualified Power Connector.Connector Replaced
05000397/LER-1989-031, :on 890806,low Reactor Pressure Vessel Level Reactor Scram Initiated by Reactor Protective Sys in Response to Actual Low Water Level Condition Caused Unplanned Trip of Reactor Feedwater Pump 1B
05000397/LER-1990-006, :on 900308,10CFR50 App R Cable Fire Protection Review Identified 12 New Cables in Fire Areas Vulnerable to Design Basis Fire.Caused by Equipment Design Deficiency. Items Placed on Hourly Fire Watch
05000397/LER-1990-007, :on 900314,review of Plant Procedures Associated W/Diesel Generator Fuel Oil Testing Showed No Requirement to Check for Water in Day Tanks.Caused by Less than Adequate Procedure Preparation
05000397/LER-1990-010, :on 900517,secondary Containment Isolation Occurred During Reactor Refueling Outage.Caused by Inadequate Work Control.Work Control Procedures Will Be Reviewed to Determine If Addl Steps Needed
05000397/LER-1989-016, :on 890514,reactor Operator Inadvertently Tripped Div 1 & 2 Offsite Power Supply Feeders Resulting in Loss of Power to Buses SM-7 & SM-4.Caused by Inadvertent Removal of Transformer Fuses.Fuses Reinserted
05000397/LER-1989-002, :on 890130,reactor Scram Occurred Due to Turbine Control Valve Fast Closure Actuation of Reactor Protective Sys Logic.Caused by Equipment Design Deficiency. Damaged 500 Kv Insulator Stack Replaced
05000397/LER-1989-012, :on 890505,unplanned Reactor Scram Occurred During Performance of Reactor Protection Sys Logic Sys Functional Test.Caused by Procedural Inadequacy.Procedure Will Be Revised to Provide Specific Resetting
05000397/LER-1990-024, :on 900907,diesel Generator Started on Undervoltage Due to Voltage Disturbances
05000397/LER-1989-022, :on 890530,loss of Secondary Containment During Core Alterations Due to Unisolatable Lines Occurred.Caused by Simultaneous Activities.Rhr Heat Exchanger Isolation Valves Closed to Reestablish Integrity
05000244/LER-1996-001, :on 950504,inservice Test Not Performed During Refueling Outage.Caused by Inadequate Tracking of Surveillance Frequency.Valve Test Performed & Disassembled
05000244/LER-1993-002, :on 930404,during 1993 SG Eddy Current Exam, Determined 1% of Total Tubes in SG a & B Degraded.Caused by Iga & IGSCC within Tube Sheet Crevice Region.Tubes Welded Using Tube Sheet Sleeve
05000244/LER-1992-005, :on 920420,determined That 242 Tubes in a SG & 216 Tubes in B SG Required Corrective Action Due to Tube Degradation.Affected Tubes Either Sleeved or Plugged.W/
05000244/LER-1993-003, :on 930328,discovered Failures of Safeguard Svc Water Sys During Planned Maint.Caused by Design & Operating Environ.Replaced Affected Valves W/Qualified Spares.W/
05000244/LER-1992-003, :on 920229,reactor Trip Occurred Due to Lo Lo Level in Steam Generator B.Caused by Plugged Instrument Tubing for Feedwater Pump a Seal Injection Differential Pressure Switch.Turbine Flushed
05000244/LER-1992-007, :on 921224,turbine Runback Occurred & a EDG Started & Tied Into Safeguard Buses 14 & 18.Caused by Loss of Power to Safeguards.Restored Normal Power to Safeguards Buses 14 & 18
05000335/LER-1998-009, :on 981223,noted That Facility Operated Outside of Design Basis.Caused by non-conservative MSLB Analysis Inputs.Will Review SR Component Differences Between Units & Will re-baseline LTOP Analysis.With
05000389/LER-1999-002, :on 990311,SG ECT Error Caused Operation with Condition Prohibited by Ts.Caused by Deficiencies in Data Analysis Guideline Instructions.Licensee Will Change Data Analysis Guidelines for Lead Analysts.With
05000389/LER-1998-004-01, :on 980430,discovered Waste Gas Decay Tank Operation W/O Available Oxygen Analyzers,Which Is Prohibited by Ts.Caused by Inadequate Licensee Review of License Amend. Oxygen Analyzer Recalibrated
05000335/LER-1997-007, :on 970502,reactor Coolant Pump Oil Collection Sys Was Outside App R Design Bases.Identified Leak Sites Were Repaired & Mods to RCP Oil Collection Sys to Capture Any Future Leakage from Areas
05000335/LER-1997-001, :on 970221,identified Deficiencies in Post Accident Sampling Systems (Pass).Caused by Failure of Personnel to Specify Drawing Update Requirements.Added PASS to List of Maint Rule Systems
05000389/LER-1997-007-02, :on 971008,inoperable Containment Cooling Fan Resulted in Operation of Facility Outside Design Basis. Caused by non-cognitive Personnel Error.Ccs Operation Was Revised & Issued on 971013
05000335/LER-1997-004, :on 970402,refueling Machine Was Operating in Manner Prohibited by TS Due to Original Design of Refueling Machine Bypass Feature Conflicting W/Ts Requirements. Eliminated Overload Cut Off Limit Bypass
05000389/LER-1996-007-02, :on 961211,operation Prohibited by TSs Occurred Due to Inadequate Surveillance of MSIS Actuation Logic. Testing of MSIS High Containment Pressure 2/4 Actuation Logic Was Satisfactorily Performed on 961211
05000335/LER-1996-009, :on 960710,operation Prohibited by Tss.Caused by Procedural Inadequacy & Personnel Error.C/As:Rev of Maint Procedures to Include Verification That Plant Conditions IAW TS Requirements Prior to Installation
05000335/LER-1996-001-02, :on 960219,control Room Emergency Ventilation Sys Inoperable Due to Improper Sys Configuration Occurred. Caused by Inadequate Guidance & Work Controls.Cr Boundary Reviewed
05000335/LER-1996-007-01, :on 960607,1B EDG Inadvertently Started Due to Procedural Inadequacy.Reset B Channel Cias & Reenergized 1B3 4,160 Bus from Startup Transformer.Changes Made to MPs 1-0970027 & 1-0970028
05000335/LER-1996-005-01, :on 960514,wide Range Nuclear Instrumentation Channel Rendered Inoperable When Required to Be in Svc for Fuel Movement.Caused by Personnel Error.Applicable Personnel Counseled & Surveillance Procedure Revised
05000335/LER-1996-012, :on 960831,manual Reactor Trip Occurred.Caused by Increased Gas Accumulation in 1B Main Transformer. Insp of 1B Main Transformer Cooling Sys Performed & Oil Cooler Replaced
05000389/LER-1996-005-02, :on 961206,determined That Independent Operability of Trip Coils Had Not Been Adequately Tested. Caused by Inadequate Surveillance Procedure.Performed Testing of Coils & Revised Procedures
05000389/LER-1997-001-03, :on 970423,containment Isolation Actuation Occurred.Caused by Increased Radiation Levels During Removal of Upper Guide Structure.Proper Actuation of Containment Isolation Components Was Verified
05000335/LER-1993-005-02, :on 930529,discovered That One CEA of Dual Element/Control Element Drive Mechanism Potentially Unlatched.Possibly Caused by Personnel Error.Cea Relatched & Latching Procedure Modified
05000335/LER-1995-007, :on 950817,inadvertent Containment Spray Via 1A Low Pressure SI Pump While Venting ECCS During Startup Due to Inadequate Procedure.Operators Stopped 1A LPSI Pump & Isolated SDC HX to Stop Spray
05000389/LER-1992-008-02, :on 921105,digital Data Process Sys Indicated Power Level Slightly Greater than 100%,due to RTD Instrument Error.Failed RTDs Will Be Evaluated by Consultant for Root Cause Analysis
05000389/LER-1992-002-03, :on 920430,containment Pressure Channel C Sensing Line for Containment Pressure Instrument PT-07-2C Process Line in Containment Capped.Caused by Personnel Error.Cap on Channel C Removed
05000389/LER-1992-001, :on 920421,three of Four Local Power Density pre-trips in RPS Alarmed & Turbine Remained Tied to Sys Grid.Caused by Inadequate Core Axial Shape Index Mgt Guidelines.Procedures Changed
05000389/LER-1992-003-03, :on 920526,EDG 2B Inadvertently Actuated When Relay Installed in Cubicle 1 of 4,160-volt Bus 2B3.Caused by Design Error.Electrical Loads Returned to Normal & Test Circuit Design Will Be Changed
05000389/LER-1989-002-01, :on 890309,containment Isolation Valve for Primary Water Had Leak Rate in Excess of Tech Specs.Caused by Failure to Perform post-maint Leak Rate Testing Due to Procedural Deficiency.Valve Repacked
05000397/LER-2017-001, Regarding Contactor Coil Failure Results in Tripping of HPCS Diesel Mixed Air Fan
05000410/LER-1990-021-01, :on 901026,TS Violation Re RHR Sys Valve Tests Not Included in Inservice Test Pump/Valve Program Plan Occurred
05000366/LER-2016-002, Regarding Group 1 Isolation Received During Turbine Testing
05000219/LER-2015-003, Regarding Failure of the No. 1 Emergency Diesel Generator to Start During Surveillance Testing
05000331/LER-2015-002, Regarding Unanalyzed Condition Due to Degraded Primary Containment Suppression Pool Coating
05000348/LER-2015-001, Regarding Automatic Actuation of the Auxiliary Feedwater System When the 1B SGFP Was Tripped
05000425/LER-2015-002, Regarding Inadvertent Auxiliary Feedwater Actuation
05000397/LER-2014-002, Regarding Unanalyzed Condition Resulting from Direct Current (DC) Ammeter Circuits Without Overcurrent Protection
05000454/LER-2014-003, Regarding Diesel Generator Actuation Due to System Auxiliary Transformer 142-2 Relay Actuation and Loss of Off-site Power (LOOP)
05000373/LER-2014-001, Regarding Secondary Containment Inoperable Due to Interlock Doors Open
05000259/LER-2013-006-02, Regarding B Standby Liquid Control Pump Inoperable for Longer than Allowed by the Technical Specifications
05000397/LER-2014-001, Regarding Secondary Containment Pressure Exceeded
05000424/LER-2013-001, Unit 1, Regarding Failure to Comply with Technical Specification LCO 3.8.4
05000397/LER-2013-002, Main Control Room Cooler Failed Surveillance
05000296/LER-2013-001, Regarding Inoperable Emergency Diesel Generators Due to Failed or Degraded Electric Generator Casing Fan Bearings
05000259/LER-2012-010, Re Browns Ferry, Unit 1 Primary Containment Isolation Valve Inoperable for Longer than Allowed by the Technical Specifications
05000305/LER-2012-001, Regarding Pressurizer PORV and Reactor Coolant System Vent Valves Appendix R Spurious Operation Concerns
05000259/LER-2011-008-01, Regarding High Vibrations on High Pressure Coolant Injection Booster Pump Thrust Bearings
05000366/LER-2011-002, Regarding Corrosion Induced Bonding Results in Setpoint Drift for Multiple Safety Relief Valves
05000425/LER-2010-002, Unit 2 Regarding High Head Safety Injection Rendered Inoperable Due to an Inadequate Review of Scheduled Work
05000457/LER-2010-002, Re Containment Spray Pump Suction Valve Failed to Close Resulting in an Unanalyzed Plant Condition Due to Procedure Error
05000425/LER-2010-001, Regarding Closure of RHR Injection Valve in Mode 1
05000374/LER-2009-002, Regarding Completed Plant Shutdown Due to Unidentified Leakage in Excess of Technical Specification Limit
05000259/LER-2009-006, Regarding Inoperable High Pressure Coolant Injection Pump Due to Emergency Core Cooling System Inverter Failure
05000366/LER-2009-002, Primary Containment Allowable Bypass Leakage Rate Exceeded Due to Failure of Feedwater Check Valve(S)
05000366/LER-2009-001, Regarding Safety Relief Valves Allowable Test Range Exceeded Due to Setpoint Drift
05000302/LER-2008-003, Manual Reactor Trip Due to Main Feedwater System Oscillations Caused by an Inconsistent Procedure
05000298/LER-2007-006, Procedural Guidance Leads to Rendering Second Diesel Generator Inoperable
05000425/LER-2002-007-02, 2 for Vogtle Regarding Unit 2 Main Generator Tripped Resulting in an Automatic Reactor Trip
05000529/LER-2005-006, Regarding Condition Prohibited by Technical Specifications Due to Partial Fouling of B Diesel Generator (EDG) Fuel Oil Strainer
05000529/LER-2007-001, Re Completion of a Shutdown Required by Technical Specification 3.5.3, Condition C
05000321/LER-2006-003, Regarding Personnel Error Results in Failure to Report Condition Prohibited by Technical Specifications
05000424/LER-2006-002, Unit 1 Re Three Technical Specification (TS) Instruments Were Determined to Be in a Condition Which Was Prohibited by TS
05000293/LER-2006-002, Re Small Quantities of Unaccountable Licensed Material
05000483/LER-2006-003, Re Unexpected Inoperability of the Emergency Exhaust System Due to Inoperable Pressure Boundary
05000271/LER-2005-002, Re Primary Containment Leak Risks Testing Program Second Barrier Isolation Valve Found Miss-Positioned
05000327/LER-1950-001, Re Automatic Reactor Trip Following Loss of Turbine Auto Stop Oil (ASO) Pressure
05000413/LER-2004-004, Regarding Spurious Moisture Separator Reheater High Level Actuation Resulting in an Automatic Turbine Trip and Reactor Trip
05000219/LER-2004-007, Regarding Automatic Containment Isolation Bypassed During Reactor Startup Due to an Inadequate Procedure
05000269/LER-2004-004, Re Improper Overloads Installed on Control Room Ventilation Filter Train
05000219/LER-2004-005, Regarding Main Steam Isolation Valve Failure to Close During Partial Valve Closure Surveillance Due to Mechanical Binding
05000425/LER-2003-001, Regarding Technical Specification Required Shutdown Not Performed Following Issuance of Notice of Enforcement Discretion
05000275/LER-2003-007-01, Re Technical Specification 3.8.4 Violation Due to Common Mode Battery Charger Failures
05000219/LER-2003-004, Actuation of Reactor Protection System Due to Instrument Malfunction
05000410/LER-2003-001, Regarding Oscillation Power Range Scram Due to a Power and Flow Perturbations Resulting from a Power Supply Failure
05000498/LER-2003-004, Regarding Deviation from a Licensed Condition Under 10CFR50.54(x)
05000301/LER-2003-005, Re Manual Reactor Trip and Manual Safety Injection Due to Pressurizer Low Level
05000305/LER-2001-002-03, Re Non-Rated Fire Barrier Separating Redundant Appendix R Safe Shutdown Capabilities
05000341/LER-2003-001, Loss of High Pressure Coolant Injection Safety Function Due to Closure of Steam Supply Valve
05000219/LER-2003-002, For Oyster Creek Unit 1 Regarding Completion of Reactor Shutdown Required by Tech Specs Due to a Cable Fault
05000277/LER-2003-001, Regarding Outboard Main Steam Isolation Valve Instrument All Line Failure Results in Scram on Reactor High Pressure
05000220/LER-2002-002, Re Loss of One Control Rod Drive Pump Train Due to Circuit Breaker Failure
05000313/LER-2002-003, For Arkansas Unit 1 Reactor Coolant System Pressure Boundary Leakage from a Crack in a Control Rod Drive Mechanism Nozzle Reactor Vessel Head Penetration Weld Due to Previous Weld Repair Method
05000395/LER-2002-004, Automatic Reactor Trip Subsequent to Feedwater Pump Trip on June 17, 2002
05000286/LER-2002-001, Operation in Condition Prohibited by Technical Specifications Due to Inoperable Service Water Pipe Caused by Leak Exceeding AOT
05000368/LER-2002-001, Reactor Coolant System Pressure Boundary Leakage Due to Primary Water Stress Corrosion Cracking of Pressurizer Heater Sleeves
05000388/LER-2002-002, Re Loss of Control Structure Chiller Safety Function When 4.16 Kv Breakers Found Racked-Out
05000247/LER-2000-001, Unit, 2 - Manual Reactor Trip Following Steam Generator Tube Rupture Dtd 03/17/2000
05000306/LER-1998-003-02, :on 980526,discovered Inadequate App R Fire Barriers & Unsealed Fire Barrier Penetrations.Caused by Lack of Adequate Separation of Safe Shutdown Equipment.Firewatch Has Been Established as Compensatory Measure
05000348/LER-2022-001, Outdated Relay Settings Resulted in an Automatic Reactor Trip After a Floor Tile Was Dropped in High Voltage Switch House
05000302/LER-1997-024, :on 970731,feedwater Valves Did Not Meet Requirements for Main Steam Line or Feedwater Line Break Event Mitigation.Caused by Inadequate Design & Calculation Errors.Fsar Will Be Updated by 971130
05000382/LER-1997-012, :on 970404,programmatic Breakdown of Overtime Program Occurred.Caused by Lack of Mgt Oversight in Administering & Implementing Plants Working Hour Policy. Ltr Issued Reemphasizing Working Hour Policy
05000302/LER-1995-023, :on 951027,engineering Personnel Determined Bldg Spray Flow Valves Used in Various Engineering Calculations Inconsistent.Caused by Design Analysis Deficiency.Problem Rept Issued
05000318/LER-1996-001-01, :on 960227,breakers 552-41,552-21 & 552-61 Tripped Open in Plant Switchyard.Caused by Failure of Auxiliary Relay Card in Breaker 552-41.Failed Relay Card Replaced
05000331/LER-1994-008, :on 940517,determined That Testing Had Not Been Performed at Required Surveillance Frequency for Reactor High Pressure Scram Pressure Switch.Caused by Inadequate Tracking.Appropriate Half Scram Inserted