05000354/LER-1998-003-01, :on 980407,concurrent Inoperability of a & B CR Chillers Was Noted.Caused by Personnel Error. Performed IST Tests,Equipment Repairs,Training & Revised Procedures
05000413/LER-1987-025, :on 870629,vent Flow Rate Manual Calculation Not Performed within 4 H Tech Spec Limit.Caused by Personnel Error.Personnel Counseled & Procedure Revised to Clarify Procedural Steps Re Notification
05000346/LER-1997-002-01, :on 970122,identified Potential Overpressurization of Penetrations During Accident Conditions.Installed Mod to Protect Component Cooling Water Supply from Overpressurization Concerns on 970504
05000346/LER-1998-001-02, :on 980407,main Steam Safety Valves Setpoints Were Outside of TS Allowable Values.Cause Will Be Investigated.Setpoint of Valve Adjusted to Be within Allowable Value
05000461/LER-1999-009, :on 990617,failure to Satisfy Secondary Containment Bypass Leakage Rate TS Was Noted.Caused by Failure to Properly Classify Containment Penetrations. Procedures Revised.With
05000368/LER-1999-001, :on 990108,TS Requirements for as-lift Settings of MSSV Were Not Met.Caused by Errors in Determination of Effective Seating Area by Vendor During Test Device Qualification.Replaced All Mssvs.With
05000325/LER-1999-003-01, :on 970724,chlorinator Flange Leak Resulted in Cb Emergency Air Filtration Sys Actuation.Caused by Inadequately Manufactured Gas Inlet Line Spool Piece. Chlorinator Flange Inlet Line Spool Piece 2 Was Replaced
05000219/LER-1999-001-02, :on 990208,noted Prolonged Operation of TB with Condenser & Heater Bay Pressure.Caused by Loss of Integrity of Ventilation Envelope (Physical Boundaries).Alternate Exhaust Fan Was Placed in Service.With
05000414/LER-1998-006-04, :on 981021,rod Control Sys Malfunction Occurred Due to Failed Card Leading to Manual Reactor Trip & Esf. Reactor Startup Was Suspended & Troubleshooting Efforts Were Initiated & Slave Cycler Lift Decoder Card Was Replaced
05000285/LER-1998-014, :on 981021,emergency Temporary Mod Placed Plant in Unanalyzed Condition Re Ventilation Duct.Caused by Inadequate Procedural Control of Emergency Temporary Mod. Plant Procedures Will Be Revised.With
05000220/LER-1998-015-01, :on 980804,breach of Primary Containment Was Noted.Caused by Personnel Error.Closed Heat Exchanger Vent Valves & Restored Torus Pressure.With
05000285/LER-1997-005, :on 970530,improper Entry Into High Radiation Area Occurred.Caused by Lack of self-checking & Inattention to Detail.Discussed Event W/Plant Staff & Counseled Individual Involved
05000285/LER-1997-006, :on 970606,discovered Loss of All Fire Suppression Due to Inoperability of Fire Pumps.Caused by Atypical Set of Operating Circumstances.Procedures Are Being Modified to Prevent Recurrence of Event
05000382/LER-1997-018, :on 970428,voluntary LER for Dropped New Fuel Assembly Was Issued.Caused by Human Error.Sfhm Grappling Tool Was Inspected for Damage or Misalignment
05000245/LER-1997-024-01, :on 970409,miscoordination of Breakers Caused Loss of QA to non-QA Isolation.Caused by Inadequate Original Design,Mod Review & Commitment Tracking.Conducted Training for Electrical Engineering Personnel Coordination Issues
05000219/LER-1996-013, :on 961113,mounting Bolts Were Missing from a Seismic Restraint Frame Around (MCC)DC-2.Caused by Personnel Error.Required Reading Will Be Issued & Job Orders Provided with Specific Instructions
05000336/LER-1996-021-01, :on 960227,snubber Failure in Pressurizer Spray Line Occurred.Caused by Corrosion.Replaced Snubber Serial 12883 W/Identical Model PSA-1 Snubber
05000395/LER-1996-006, :on 960711,failure of Abb/Ite 27N Relays Occurred.Caused by Defective Timer Integrated Circuit U5. Identified,Replaced & Tested Subject 27N Relays & Notified Vendor of Situation
05000346/LER-1996-001, :on 960304,EECS Inoperable.Caused by Inadequate Safety Review.Plant Mod to Install Manual Vent Valve Will Be Implemented in Tenth Refueling Outage
05000368/LER-1992-001-01, :on 920227,discovered That Previous Surveillance Testing of ex-core Instrumentation Logarithmic Power Level High Trips Not Performed.Caused by Inadequate Procedures.Procedures Revised
05000259/LER-1996-001-01, :on 960121,Unit 1/2 B DG Auto Started During Local Panel Testing.Caused by Failure of Blocking Diode in Start Failure Circuitry.Failed Diode Replaced & Panel Alarm Pushbutton Annuciation Circuitry Checked
05000440/LER-1995-006, :on 950901,ESF Actuation During Inverter Restoration Occurred.Caused by Personnel Error.Engineers Involved in Technical Review of Work Order Coached & Counseled by Mgt/Supervision
05000440/LER-1995-007, :on 950902,reactor Automatically Scramed.Caused by Operator Error.Operators Involved in Event Removed from Licensed Duties & Counseled W/Respect to Improper Actions
05000440/LER-1995-005, :on 950831,reactor Automatically Scramed.Caused by Equipment Failure.Inverter Unit Replaced & Instrument Power Supply Restored
05000272/LER-1995-026, :on 951023,MSSV Failed Lift Set Test.Cause Under Investigation.Appropriate Enhancements Will Be Made to Safety Valve Program Based on Results of Root Cause Determination
05000298/LER-1995-010, :on 950413,unanalyzed Condition Discovered During Closeout of RHR Min Flow Valve Design Change (DC) 94-332.Caused by Improper Review of Previous DC 76-2.Util Implemented DC 94-332
05000313/LER-1991-010-03, :on 911005,discovered That Offsite Power Source May Be Unable to Maintain Adequate Voltage to Safety Loads During Accident Conditions.Caused by Increased Offsite Grid Loading.Procedural Guidance Implemented
05000313/LER-1991-005-02, :on 910521,automatic Reactor Trip on Loss of Main Feedwater Occurred.Caused by Inadequate Procedural Guidance Re cross-tie of Electrical Load Ctrs.Personnel Involved Counseled
05000423/LER-1995-004, :on 950322,historical Breaches Affected CR Pressurization & Secondary Containment Vacuum Due to Misinterpretation of Ts.Work Controls Minimized Possibility of Pressure Boundary Breaches
05000456/LER-1995-004-05, :on 950409,RT Occurred Due to Failed Capacitor in Firing Card That Caused Loss of Vital AC Instrument Bus 11.Replaced Firing Board in Instrument Inverter W/New One
05000313/LER-1991-009-03, :on 911003,discovered That 480-volt Ac ESF Load Ctrs 2B5 & 2B6 Not in Seismically Qualified Configuration & Support Rails Not Secured in Place.Caused by Insufficient Design Review.Rails Removed
05000313/LER-1991-007-02, :on 910614,during Insp,Fuse Discovered Inadequate.Caused by Design Inadequacies.Firewatches Posted in Areas of Common Vulnerability & Fuses for Emergency Batteries Replaced
05000313/LER-1990-010-02, :on 900915,determined That Check Valves Located in Air Supply Sys to Dampers Used for Isolation of ANO-1 Ventilation Sys Not Previously Tested
05000321/LER-1993-015, :on 931128,high Pressure Coolant Injection Sys Experienced Momentary Inoperability Due to Power Supply Transient.Hpci Sys Restored to Operable Status & Procedures Revised
05000456/LER-1994-005-01, :on 940323,inadvertent Start of DG 1B Occurred During Surveillance Testing.Caused by Miscommunication Between Personnel.Offsite Power Restored to Bus 142 & DG 1B Secured
05000313/LER-1990-005, :on 900703,possible Failure of Containment Isolation Valve Associated W/Letdown Sys Discovered.Caused by Inadequate Electrical Separation Between Safety & nonsafety-related Components.Mod Installed
05000368/LER-1990-014, :on 900626,automatic Reactor Trip Occurred Due to Erroneous Control Element Assembly Position Indication
05000281/LER-1993-006-03, :on 931115,Unit 2 Experienced Automatic Reactor Trip.Caused by Electrical Circuit Failure.Electrical Failure Traced to Defective Circuit Breaker & Replaced
05000400/LER-1992-001-01, :on 920102,standby Injection Pump Room Ventilation Inoperable Due to Misalignment of Manual Damper & Failure to Install 2 Blank Flanges.Caused by Failure to Install Parts During Initial Construction
05000456/LER-2012-004, Regarding Notice of Enforcement Discretion Received for Ultimate Heat Sink Temperature Exceeding Technical Specifications Requirements Due to Prolonged Hot Weather
05000348/LER-2012-004, Regarding Unplanned B Train LOSP During Switchyard Breaker Testing
05000348/LER-2012-001, Seismically Qualified RWST Aligned to Non-Seismic Piping
NL-11-2445, LER 11-S01-00 for Joseph M. Farley, Unit 1 Regarding Loss of Power to Security Systems
05000456/LER-2011-004, Regarding Non-Conservative Historic Assumptions Identified in Turbine Building High Energy Line Break Analyses Result in Potential for Two Channels in a System to Become Inoperable
05000455/LER-2011-002, For Byron Station, Unit 2, Regarding Containment Pressure Not within Limits Longer than Allowed by Technical Specifications Due to Personnel Error
05000424/LER-2011-001, Regarding Reactor Trip Due to I a Reactor Trip Breaker Opening
05000285/LER-2010-006, Regarding Reactor Trip Due to Erroneous Moisture Separator Trip Signal
05000333/LER-2010-004, Regarding Main Steam Isolation Valve Leak Rate Exceeds Authorized Limit
05000321/LER-2010-005, Unit 1 Regarding Inability of Redundant Main Control Room Air Conditioner to Auto-Start for Pressurization Mode
05000455/LER-2010-001, Reactor Protection and Auxiliary Feedwater System Actuation Signals from Low Steam Generator Level Due to Inadequate Surveillance Testing
05000321/LER-2010-002, Regarding Degraded Plant Service Water Cooling to Main Control Room Air Conditioner Results in Loss of Function
05000457/LER-2009-003, For Braidwood, Unit 2, Regarding Drain Procedure for ECCS Suction Line Creates an Unanalyzed Condition Due to Inadequate Configuration Requirements
05000457/LER-2009-002, Regarding Loss of Offsite Power Coincident with a Reactor Trip Due to Loss of 2C Reactor Coolant Pump
05000366/LER-2009-004, Turbine Trip on High Reactor Water Level Due to Failed Circuit Board Results in Reactor Scram
05000321/LER-2009-005, Licensee Event Report Inadequate Procedure Results in a Group 1 Isolation and Reactor Scram
05000456/LER-2009-001, For Braidwood Station, Unit 1, Steam Generator Tube Exceeding Plugging Criteria Remained in Service During Previous Cycle
05000457/LER-2008-002, Reactor Trip on Unit Auxiliary Transformer 241-1 Sudden Pressure Relay Actuation Due to 2C Heater Drain Pump Motor Electrical Fault
NL-10-0577, LER 10-S01-00 for Vogtle, Units 1 & 2 Regarding Supplemental Workers Unescorted Access Not Revoked in a Timely Manner
05000348/LER-2007-003, Regarding Component Cooling Water Pump Breaker Failures
05000366/LER-2006-001, Component Failure Leads to Inoperability of the HPCI System
05000353/LER-2003-002, MSIV Closure Time During Hot Conditions
05000266/LER-2001-005, Page 3 of LER 01-005-00 and 4 Pages of Information on Point Beach Procedures
05000528/LER-1993-001-01, :on 930130,main Turbine Trip Occurred Which Initiated Manual Reactor Trip After Receiving High Pressurizer Pressure Pretrip Alarm.Caused by Failure of High Tank Level Controller.Failed Controller Replaced
05000366/LER-2013-001, Regarding Unplanned RPS Actuation Due to Scram Discharge Volume High Level During Surveillance Test
05000455/LER-2009-001, Re Late Entry Into Technical Specification Condition Associated with Reactor Coolant System Leakage Characterization Resulting in a Condition Prohibited by Technical Specifications
05000336/LER-1995-042, :on 951115,failed to Perform SR 4.8.1.1.1, Offsite Line Verification Due to Inadequate Communication. Revised Procedure Sp 2619A to Ensure That TS Action Statement SRs Documented
05000333/LER-1995-011-01, :on 950531,leakage of Primary Containment Isolation Valves Was Exceeded.Caused by 02-2AOV-39 & 02- 2AOV-40 Experiencing Repeated Difficulty in Passing Llrt. Flushed Seat on Inboard Isolation Valve
05000219/LER-1994-018, :on 940924,containment Exhaust Valves Inadvertently Isolated Due to Improper Switch Position. Caused by Fabrication Deficiency.Four Isolated Valves Reopened & Surveillance Procedure Revised
05000382/LER-1994-014-01, :on 941006,HLIV Circuit Breaker Left in Open Position Due to Personnel Error.Cognizant CRS Has Been Counseled in Accordance W/Waterford 3 Improving Human Performance Program