05000336/LER-1988-003, :on 880130,inadvertent Automatic loss-of-normal Power Actuation Occurred on Two of Engineered Safeguards Actuation Sys.Immediate Cause Not Apparent.Wiring Error Identified & Corrected
05000457/LER-1988-029-02, :on 881025,reactor Manually Tripped When Alarm Received at Main Control Panel for High Suction Strainer Differential Pressure for Condensate Pumps 2A & 2C.Caused by Plugged Suction Strainers.Condenser Cleaned
05000423/LER-1987-038-01, :on 871110,loss of 4.16 Kv Vital Bus Occurred Due to Mechanical Shock.Caused by Broom Handle Impacting Switchgear Door in Close Proximity to Relay.Warning Signs & Tape Returned to Position
05000289/LER-1998-006-01, :on 980617,Thermo-Lag Fire Barrier Was Found Installed Outside Approved Joint Design Arrangement,Was Identified.Caused by Personnel Error.Hourly Fire Watch Initiated
05000320/LER-1998-001-02, :on 980604,flood Barriers Breached Between Turbine Bldg & Control Bldg Area.Caused by Work Planning Process for Dismantlement Work Failed to Include Adequate Controls.Openings Verified to Be Sealed
05000289/LER-1998-003, :on 980218,discovered Installation of Thermo- Lag Fire Barrier on Incorrect Conduit Duct.Caused by Personnel Error.Revised Operating Procedure 1104-45 & Installed One Hour Fire Rated Barrier on Subject Cable Duct
05000289/LER-1998-004, :on 980218,loss of CS Capability Was Noted. Caused by Improper Assembly of RBS Pump Discharge Valve Control Switch Pushbutton.Pushbutton Switch Was Replaced W/New Properly Assembled Pushbutton Switch
05000289/LER-1999-009, :on 990626,automatic Start of EDG 1A Occurred. Caused by Failure of Fault Pressure Relay on Auxiliary Transformer 1B.Failed Pressure Relay Has Been Replaced
05000289/LER-1997-009-01, :on 970725,engineering Analysis of Loss of a Train DC Power W/Loss of Offsite Power & LOCA Was Determined.Caused by Plant Designers Error.Trained Operators on Methodology to Regain Control of Es Equipment
05000289/LER-1999-003-01, :on 990310,discovered Failure of Manual Balancing Damper in Supply Duct of Control Bldg Evs.Caused by Failure to Adequately Review Risk & Consequences of Change.Failed Damper Was Clamped Open
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
05000289/LER-1999-005, :on 990514,open Flood Path Between Turbine Bldg & Control Bldg Was Noted.Caused by Failure to Recognize That Mods Affected Flood Protection.Revised Flood Procedures.With
05000289/LER-1988-001-02, :on 880316,CRD Breaker Failed Undervoltage Trip Test.Caused by Undervoltage Trip Paddle Lodged Over Armature Disk.Breaker Replaced.Maint Procedures Will Be Revised to Provide Direction for Verifying Dimensions
05000289/LER-1998-010-01, :on 980825,potential Violation of Design Criteria During Single Auxiliary Transformer Operation Occurred.Caused by Failure to Adequately Define Job Performance Stds.Temporary Change Notice Issued
05000289/LER-1988-004-02, :on 880813,reactor Coolant Pump Tripped & Heat Seek Protection Sys Actuated to Start Emergency Feedwater Pumps.Caused by Inadequate Procedural Guidance.Test Procedure Changed & Test Completed
05000289/LER-1998-009-01, :on 980820,discovered Potential Loss of HPI During Postulated Loca.Caused by Misapplication or Interpretation of Design Inputs.Revised OL Was Implemented & Mut Pressure & Level Limits Analysis Revised
05000289/LER-1998-008-01, :on 980818,RM RM-A-8G-High Was Noted Inoperable for More than 7 Days.Caused by Weaknesses in I&C Work Practices.Revised Data Collection Portion of Surveillance Procedures
05000289/LER-1997-006-01, :on 970424,reactor Bldg Fan Motors Unqualified Cable Termination Occurred Due to Incorrect Engineering Guidance.Caused by Personnel Error.Qualifiable Repair of AH-E-1A Fan Motor Termination Was Installed on 970323
05000289/LER-1997-005-01, :on 970410,declared motor-operated Reactor Bldg Purge Valves Inoperable Due to Inadequate Closing Torque. Caused by Deficient Design Analysis.Will Perform Evaluation of Valve Specific Seating Torque Test Data
05000289/LER-1997-002, :on 970129,potential Inability of Startup Feedwater Block Valves to Fully Close Following Main Steam Line Break Occurred Due to MOV Program Weakness.Increased Torque Switch Settings on Valve Operators
05000289/LER-1997-001-01, :on 970117,potential Overpressurization of Piping Between Closed Reactor Building Isolation Valves Occurred Due to Inadequate Design Code Guidance.Results of This Review Will Be Documented
05000289/LER-1996-001, :on 961112,investigation of Seismic Qualification of Class 1E 4160 W Breakers Was Conducted Due to Incident Caused by Personnel Error.Racked Out Breakers Were Removed from Associated Modules
05000289/LER-1997-001-02, :on 970117,potential Overpressurization of Piping Between Closed Reactor Building Containment Isolation Valves Occurred Due to Inadequate Design Code Guidance. Results of Review Will Be Documented.Pages 2 & 3 Corrected
05000289/LER-1996-001-02, :on 961112,Westinghouse Class IE 4160 Vac Switchgear W/Breakers Were Not Seismically Qualified.Caused by Personnel Error.Racked Out Breakers Were Removed from Modules & Seismically Restrained
05000289/LER-1996-001-01, :on 961112,determined That Westinghouse Class IE 4160 Vac Breakers Were Not Seismically Qualified.Caused by Personnel Error.Removed Racked Out Breakers from Modules & Seismically Restrained
05000289/LER-1991-008-01, :on 911223,discovered Misfiled Surveillance Notification Form Specifying Core Flood Tank Monthly Boron Sample Days Beyond Latest Date.Caused by Personnel Error. Surveillance Tracking Practice Revised
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
05000289/LER-1992-003-01, :on 921019,discovered Reactor Building Atmospheric Radiation Monitor Inoperable Due to Personnel Error Which Caused Improper Valve Lineup.I&C Technician Has Been Counseled
05000289/LER-1992-001, :on 920122,inadvertent Emergency Feedwater Initiation Occurred During Planned Maint.Caused by Installation Error.Wire Errors Affecting Sys Operation Corrected
05000289/LER-1995-005-01, :on 951012,invalid Heat Sink Protection Sys Actuation Occurred.Caused by Failure of Logic Modules.Logic Module Failure Analysis Will Continue in Order to Substantiate Suspected Failure Mode
05000289/LER-1995-003-01, :on 950909,reactor Coolant Leak Occurred Due to Crack Weld in Cold Leg Drain Line.Failed Line Replaced.W/
05000289/LER-1991-001-02, :on 910707,inoperability of Degraded Grid Voltage Relays Resulting from Reinstallation of Volt Breaker.Caused by Physical Configuration of Switchgear Cubicle.Engineering Evaluation Performed
05000289/LER-1991-007-01, :on 911113,main Feedwater Pump Intentionally Tripped During Plant Heatup to Verify Stop Valve Closure. Both motor-driven ESF Pumps Started.Caused by Personnel Error.Event Reviewed W/Personnel
05000289/LER-1991-006-01, :on 911104,discovered Increased Potential for post-LOCA Boron Precipitation.Caused by Error in NSSS Vendor Licensing Basis Analysis.Util Will Confirm Calculations to Support Conclusions within 1 Month
05000289/LER-1991-005-02, :on 911101,in Process of Bypassing Train a, Operator Depressed Incorrect Pushbutton,Causing ESAS Actuation of Channel A.Caused by Personnel Error.Operator Counseled & Plant Incident Rept Written
05000289/LER-1991-004-02, :on 911008,irradiated Fuel Assembly Moved W/O Verification of Containment Integrity During Performance of Main Fuel Bridge Hoist Test.Caused by Procedural Weaknesses/ Personnel Error.Incident Reviewed W/Personnel
05000289/LER-1991-002-02, :on 910724,reactor Tripped on Low RCS Pressure Due to Control Rod Group 7 Dropping Into Reactor Core.Caused by Personnel Error & Equipment Failure.Components Repaired & Maint Personnel Trained
05000289/LER-1995-001-01, :on 950307,RC Leak Caused by Failure of Parker Hannifin Compression Fitting Due to Insufficient Tightening During Installation.Shut Root Valves & Stopped Leak
05000336/LER-1994-017, :on 940601,inadvertent ESAS Actuations Occurred.Caused by Deenergizing of Engineered ESAS Facility 2 Actuation Cabinet.Revised Operations Procedure 2384
05000289/LER-1991-003-02, :on 910927,turbine Control Valves Started Opening rapidly,once-through Steam Generator Pressure Began to Drop & Reactor Trip Occurred During Testing.Caused by Inadequate Procedure.Procedure Revised
05000289/LER-1989-002, :on 891114,radiator Fan Right Angle Gear Drive Bearing Lubrication Discovered Inadequate Due to Formation of Sludge in Lubrication Lines.Caused by Inadequate Procedure.Plant Procedures Revised
05000289/LER-1994-006-01, :on 941002,inadvertent Actuation of EG-Y-1B Occurred Due to Personnel Error.Lead replaced,86B/E Relay Reset & EG-Y-1B Breaker Automatically Closed
05000289/LER-1994-005-01, :on 940609,noted Irregularity in Overlap Between Average Positions of Control Rod Groups 6 & 7 Due to Intermitent Failure of CRD Sys Programmer Motor.Group 7 Programmer Assembly Will Be Replaced
05000289/LER-1994-003-01, :on 940523,level of Sodium Hydroxide Tank Incorrectly Reduced Due to Personnel Error.Applicable Administrative Requirements & Computer Alarms Will Be Reviewed to Determine Need for Changes
05000289/LER-1993-007, :on 931008,pressure Isolation Valve Failed to Seat Tightly During Plant Operation Due to Loose Hinge Mechanism.Replaced Internals of Pressure Isolation Valve
05000289/LER-1993-009, :on 931112,motor Operator Failure Occurred Due to Improper Declutch Lever Installation.Eight Nuclear Safety Related Limitorque Size Smb 000 MOVs Modified W/New Balanced Declutch Levers
05000289/LER-1990-006-01, :on 900702,control Room Operator Depressed Manual RB High Pressure Actuation Pushbutton During Testing Causing Emergency Safeguards Actuation.Caused by Personnel Error.Personnel Reinstructed
05000289/LER-1993-006, :on 930701,lube Oil Accumulation Discovered on EDG EG-Y-1B Due to Inadequate Maint.Edg Removed from Svc & Leak Repaired by Retorquing Filter Housing Bolts
05000322/LER-1993-001, :on 930429,refueling Jib Crane Moved in Vicinity of Spent Fuel Pool Using vendor-supplied Lifting Eye in Violation of NUREG-0612.Caused by Failure to Identify Crane as Heavy Load.Meetings Held
05000289/LER-1993-004, :on 930503,plant Process Computer Malfunction Event Occurred Due to Suspected Hardware Problem.Cause of Malfunction Not Revealed.Computer Sys Software Change Has Been Implemented
05000289/LER-1990-003, :on 900227,turbine Bypass Valves Isolated During Plant Heatup Due to Main Steam Valve Closure.Caused by Personnel Error.Personnel Reviewed Event to Emphasize Need to Follow Administrative Requirements
05000311/LER-1990-014, :on 900419,ESF Actuation Signal for Containment Ventilation Isolation Occurred.Caused by Procedural Inadequacy.Setpoint Setting Modified & Detector Time Constant Extended from 20 to 40
05000289/LER-1993-003-01, :on 930312,reactor Tripped as Result of Reactor Coolant Pump Power Monitor Malfunction.Caused by Electrical Equipment Failure.Failed Equipment Repaired & Tested Satisfactorily
05000289/LER-1993-002-01, :on 930129,bypass Occurred of Both Decay Heat Svc Coolers.Caused by Personnel Error.Mgt Reviewed Event W/ Affected Crew & Procedures Will Be Upgraded
05000289/LER-1993-001-02, :on 930126,Pressure Switch BS-PS-286 Declared Inoperable Because of Failure to Meet Reduncy Requirement of TS Table 3.5-1.Five Remaining Similar Switches Inspected & Deadband Reset as Required
05000289/LER-1990-005, :on 900306,radioactivity Increases Occurred Due to Primary to Secondary Tube Leak in Steam Generator.Caused by Crack in Bottom of Tube Sheet.Tube Stabilized & Plugged
05000289/LER-1990-004-01, :on 900304,reactor Tripped Following Zero Power Physics Testing.Caused by Personnel Error.All Control Room Operators & Licensed Supervisors Will Review Event & Lessons Learned During Formal Training
05000320/LER-1991-004, :on 910412,processed Water Disposal Sys Sample Valve Misaligned.Caused by Personnel Error.Addl Training for Evaporator Operators & Rev to Pwds Operating Procedure & Areas of Responsibility Addressed
05000289/LER-1990-003-01, :on 900227,isolation of Turbine Bypass Valves Due to Main Steam Valve Closure.Caused by Personnel Error. Personnel Will Review Event in Order to Emphasize Need to Follow Proper Administration
05000289/LER-1990-001, :on 900107,inadvertent Trip of Reactor Protection Sys Occurred,Followed by Inadvertent Engineered Safeguards Actuation Sys Actuation.Caused by Inadequate Procedural Detail.Procedure Improvements Made
05000289/LER-1989-003-02, :on 891129,rapid Reduction in Turbine Load Occurred Resulting in High Temp & Pressure in RCS & Reactor Trip.Caused by Loose Shield Wire on Input to Speed Error Circuit.Connections in EHC Cabinet Checked
05000289/LER-1989-002-02, :on 891114,discovered That Radiator Fan Right Angle Gear Drive Bearing Lubrication Inadequate Due to Formation of Sludge in Lubrication Lines.Procedure Revised to Increase Maint on Lubrication Sys
05000289/LER-1989-001-02, :on 891030,operator Error Resulted in Inadvertent Actuation of Es Components B.No Equipment Was Damaged & Vol of Water Injected Into RCS Minimal.Operators Counseled
05000296/LER-1996-007-04, On 961213,engineered Safety Feature Actuations Resulting from Inadequate Planning of step-text Work Order Occurred.Tripped Breaker Reset & LCO Condition Exited
05000315/LER-1998-006, :on 980225,ice Basket Weighing Option Resulted in Potential Unanalyzed Condition Due to Lack of Technical Basis for Option.Caused by Failure to Maintain Design Basis for Ice Condenser.Revised Plant Procedure
05000289/LER-2017-002, Regarding Leak at High Pressure Connection on Reactor Coolant Pump a Thermal Barrier
05000289/LER-2017-001, Regarding Low Temperature Over-Pressurization (LTOP) Technical Specification Requirements Were Not Met
05000289/LER-2015-001, Regarding Seismically Qualified Bwst Aligned to Non-Seismic Piping
05000289/LER-2014-001, Regarding Unfused DC Motor Control Circuits
05000289/LER-2012-005, Regarding Reactor Trip Due to RC-P-1C Trip
05000289/LER-2012-004, Regarding Reactor Trip During Downpower Due to Condensate Booster Pump Trip
05000289/LER-2012-003, Regarding Pressurizer Heater Bundle Leak
05000289/LER-2012-001, Regarding Single Condition Making Independent Trains Inoperable
05000289/LER-2011-002, Regarding Remote Shutdown Relay 69X1RR Contact Failure
05000289/LER-2011-001, Regarding Unanalyzed Condition Affecting Probable Maximum Flood (PMF) Level
05000482/LER-2011-002, For Wolf Creek Generating Station, Regarding Diesel Generator Declared Inoperable Due to Inadequate Installation of a Fuel-Rack Control Pin
05000289/LER-2009-001, Regarding Multiple Main Steam Safety Valve Test Failures
05000289/LER-2008-001, Regarding Decay Heat River Water System Pump (DR-P-1B) Failed to Start
05000397/LER-2007-001, Regarding Automatic Depressurization System Logic Signal Instrument Inadvertently Disabled
05000289/LER-2005-002, Regarding Safe Shutdown Analysis for Control Building Fire Area 1 Was Discovered to Have Flaws in the Fire Mitigation Strategy Due to Insufficient Technical Rigor
05000289/LER-2004-001, High Pressure Injection Pump Seismic Qualification Impacted Due to an Oversight in the Design Process When Power Supplies for the Auxiliary Oil Pumps Were Relocated
05000482/LER-2004-004, Regarding Insufficient Planning Results in Reactor Trip When Restoring from Test
05000289/LER-2003-002, Regarding Reactor Building Polar Crane Hoist Operation Over the Fuel Transfer Canal During Movement of Fuel Due to Inadequate Understanding of Requirements
05000289/LER-2003-001, From Three Mile Island, Unit 1 Regarding Control Room Habitability Boundary Ventilation Access Panel Found Open Due to Latching Mechanisms Not Properly Closed
05000289/LER-2002-002, TMI-1 Pressurizer Code Safety Valve Setpoint Outside Tolerance During Plant Operation Due to Mechanical Setpoint Drift
05000289/LER-2002-001, Re Vital Power Supply Failure Due to Blown Fuse
05000271/LER-1998-012, :on 980430,six Primary Containment Isolation Valves Were Declared Inoperable.Caused by Failure to Adequately Define Standards for Reducing Contact Forces Caused by Sharp Edges.Event Rept Initiated
05000289/LER-1995-002-01, :on 950908,control Rod Trip Insertion Times Exceeded TS 4.7.1.1 Limits.Caused by Accumulation of Corrosion Deposits in CRDM Thermal Barrier Call Check Valves & Lead Screw Guide Bushing
05000289/LER-1995-004-01, :on 950912,short Term Interruption of DHR Flow Occurred Due to Inadvertent Operation of DH-V-1 During ESAS Relay Coil Replacement.Caused by Less than Adequate Procedural Guidance.Procedures Revised