05000334/LER-1998-018, :on 980409,inadequate Beaver Valley Power Station Procedures to Ensure Compliance W/Tech Specs Were Noted.Caused by Inadequate Training of Procedure Writers.Revised Procedures
05000336/LER-1988-006, :on 880218,local Leak Rate Testing Determined Combined Bypass Leakage Exceeded Tech Spec 3.6.1.2.C Limit. Caused by Debris Being Lodged in Seat Area of Valve.Duplex Strainer Installed in Piping Sys
05000461/LER-1998-017, :on 980402,inadequate Implementation of SR Was Noted.Caused by Misinterpretation of TS SR 3.8.6.2 & Table 3.8.6-1.Revised Procedure for Performing Battery Cell Specific Gravity Checks
05000220/LER-1998-013-01, :on 980604,valve Repositioning Caused non- Conformance W/App R Safe Shutdown Analysis. Caused by Failure to Include Valves 40-26 & 40-27 in UFSAR Description of App R.Circuit Breakers 40-30 & 40-31 Opened
05000382/LER-1998-003, :on 980302,inoperable Hydrogen Analyzers Were Noted Due to Undersized Thermal Overloads.Engineering Personnel Conducted all-hands Meetings to Discuss Management Expectations for Verifying Critical Design Inputs
05000413/LER-1999-015, :on 990616,discovered That Auxiliary Bldg Filtered Ventilation Exhaust Sys Was Inoperable.Caused by Improperly Positioned Vortex Damper.Damper Was Repositioned Correctly & Sys Was Retested Successfully
05000266/LER-1999-007, :on 990831,cable Tray Fire Stops Do Not Meet App R Exemption Requirements Occurred.Caused by Improper Installation of Approved Plant Mod.New Mod Has Been Initiated to Provide Three H Rated Fire Barrier
05000334/LER-1998-012, :on 980204,discovered That Capacitors Could Not Be Gauranteed to Withstand Consequences.Caused by Inadequate Implementation of Vendor Instructions.Filled Voids Between Capacitors & Circuit Boards W/Silicon Rubber
05000413/LER-1986-051, :on 860106,emergency Hatch Between Upper & Lower Containment Inoperable.Caused by Personnel Error. Importance of Instructions & Directions in Work Requests & Procedures Will Be Reviewed
05000414/LER-1999-005-02, :on 990727,missed Emergency DG TS Surveillance Concerning Verification of Availability of Offsite Power Sources,Was Declared.Caused by Defective Procedure.Revised Affected Procedure
05000220/LER-1986-002, :on 860201,radioactive Gaseous Effluent Monitoring Sys Stack Gas Sample Pump 1 Tripped.Caused by Failed Board in Microprocessing Unit.Board Replaced
05000271/LER-1997-015, :on 970827,discovered That Required Instrument Check for Recirculation Pump Trip Was Not Completed IAW Ts. Caused by Personnel Error.Devised Temporary Procedure of Performing Instrument Checks
05000445/LER-1997-007, :on 970820,post-work Testing for Containment Isolation Valve Was Not Performed After Maint.Caused by Incorrect Belief That Work Did Not Involve Replacement. Tested Valve IAW TS Requirements
05000219/LER-1997-007-01, :on 970531,DG 2 Was Inadvertently Initiated During Surveillance Testing.Caused by Personnel Error.Formal Written Expectations for Key CR Activities Were Developed & Reviewed
05000369/LER-1987-001, :on 870107,Train B Chiller for (Shared) Control Area Ventilation/Chilled Water Sys Tripped on Refrigerant Low Temp.Caused by Chiller Thermostat Setting Positioned Too Cold.Train B Switch Manually Reset
05000369/LER-1987-007-02, :on 870317,incorrect Actuation Tubing Connections on Halon Fire Suppression Sys Discovered.Caused by Failure of Procedure to Ensure That Tubing Was Properly Reconnected.Tubing Connections Corrected
05000220/LER-1999-001, :on 990125,noted That Plant Operated Outside Design Basis Due to Failure to Revise Satellite pre-fire Plans.Satellite Copies of pre-fire Plans Were Revised & Procedure Re pre-fire Plans Was Revised.With
05000454/LER-1997-023-03, :on 971229,discovered That 1B EDG Wired in Configuration,May Have Continued to Operate,If Fire Had Occurred in Zones 11.5-0 or 11.6-0.Caused by Error on Part of Technician Installing.Technician Counselled
05000321/LER-1999-002-01, :on 990429,HPCI Sys Inoperability Occurred. Caused by Vacuum in HPCI Sys Vacuum Tank.Personnel Lowered Tank Vacuum & Successfully Completed HPCI Sys Testing.With
05000341/LER-1998-010, :on 981007,SRV as Found Settings Exceed TS Setpoint Tolerance Criteria.Caused by Oxide Bonding Between Pilot Valve Disc & Seat.All 15 Pilot Valve Assemblies Were Replaced.With
05000250/LER-1986-006, :on 860211,safety Injection Sys Actuated & Subsequent Reactor Trip Occurred.Caused by Const Activities on Unit 4 & Inadequate Instructions for Investigating Event. Procedures Revised
05000425/LER-1998-007, :on 980824,loss of FW Flow Led to Manual Reactor Trip.Caused by Consecutive Failures of Primary & Backup Power Supplies to Process Control Rack 3.Repaired Inverter & Replaced Process Control Rack 3.With
05000285/LER-1997-008, :on 970616,improper Shift Staffing Due to Inadequate Control of Respirator Spectacle Kits Occurred. Caused by Program for Obtaining Corrective Lenses Inadequate to Ensure Compliance w/10CFR.Manual Revised
05000219/LER-1997-004-01, :on 970312,discovered That RWC Valve May Not Operate During Line Break Due to Personnel error.V-16-2 Was Declared Inoperable & Deactivated in Closed Position to Stop Opening W/Pressure Greater than 125 Psig
05000412/LER-1996-007-01, :on 961015,CR Ventilation Sys Was Operated in Purge Mode to Ventilate Paint Fumes from Cr,Temporarily Rendering CR Emergency Bottled Air Pressurization Subsystem & Esf,Inoperable.Changed Planning Processes
05000278/LER-1992-002, :on 920117,discovered That DW Oxygen Concentration Level Exceeded Value Specified in Ts,Due to an Analyzer Failure.Round Sheets Have Been Revised to Include Instrument Nitrogen Compressor Run Times
05000293/LER-1992-015, On 921125,RCIC Became Inoperable & 7-day LCO Entered.Caused by Turbine Trip Throttle Valve Closing When Valve Linkage Accidently Contacted.Valve Manually Reset & Personnel Counseled & Instructed
05000302/LER-1996-015, :on 960408,determined That Cables Routed Improperly Due to Personnel Error.Cables Routed to MCB-SSR Replaced W/Appropriate Cables & Mods of Circuits Associated W/Toxic Gas Monitors Completed
05000440/LER-1992-018, :on 920708,hourly Fire Watch of Inoperable Fire Barriers Not Performed as Required.Caused by Personnel Error.Counseling & Disciplinary Action Administered
05000317/LER-1996-003, :on 960423,discovered Holes in Containment Sump Screen Larger than Described in Ufsar.Holes Most Likely Installed During Plant Const.Sump Screens Visually Inspected & Repaired
05000423/LER-1995-020-02, :on 951202,discovered Leak on Valve Stem leak-off Pipe for RHR Supply from RCS Loop a Inboard Isolation Valve.Caused by Mechanical Damage Resulting from Tensile Overboard.Removed Pipe & Valve Weld
05000333/LER-1995-013-01, :on 950905,discovered Loss Feedwater Flow Transient Due to Personnel Error.Revised Abnormal Operating Procedure AOP-1
05000423/LER-1995-011-01, :on 950515,mussel Shells Found in Recirculation Spray Sys Heat Exchanger.Caused by High Density of Mussel Plantigrades in Spring 1994.Hypochlorite Metering Pumps Installed
05000336/LER-1994-028-01, :on 940923,TS Surveillance Not Performed within Required Time Interval Due to Assuming That 24 Month LLRT Began After LLRTs Completed from Current Refuel Outage.Past LLRT Surveillance Intervals Reviewed
05000366/LER-1994-009-02, :on 941220,failed Component Results in Unplanned Engineered Safety Feature Sys Actuation.Relay Coil Was Replaced
05000445/LER-1991-013, :on 910328,loss of Offsite Power Occurred. Caused by Grounded Transmission Line Due to Accumulation of Bird Droppings on Insulators.Increased Attention Given to Need for Cleaning
05000325/LER-1991-007, :on 910305,reactor Scram Occurred.Caused by Personnel Error Re Failure to Perform Calibr & Installation of Relay.Develop Plan to Address Recurring Problems & Training Provided
05000328/LER-1990-016-01, :on 901117,determined That Unit 2 Operated in Noncompliance W/Tech Spec 2.2.1 & LCO 3.3.1 Because of Nonconservative Calibr of Nis Intermediate Range Channels. Caused by Procedural Inadequacies
05000366/LER-1993-008-02, :on 931103,turbine Stop Valve Failure Resulted in HPCI Sys Inoperability Due to TSV Binding in Open Position.Tsv Repaired & HPCI Sys Returned to Svc on 931105
05000382/LER-1993-006-02, :on 931019,UHS & WCT Water Basins Less than 97% Full.Caused by Failure to Follow Procedure.Logs Revised to Indicate DWST Level Should Be Maintained Higher than Piping Logs
05000285/LER-1993-002, :on 930122,determined That Current SG LP Signal Block Reset Values Greater than Allowed Ts.Caused by Improper Design.Test Procedures Will Be Revised by 930917 to Specify Desired Value for Block Function
05000259/LER-2013-002, Regarding Manual Reactor Shutdown Due to Decreasing Condenser Vacuum
05000220/LER-1998-012-01, :on 980521,determined That Fire Dampers Installed in Supply & Return Ducts to Auxiliary CR Would Fail Closed as Result of Loop.Caused by Inadequate Evaluation.Modified Affected Fire Dampers
05000334/LER-1998-008, :on 980207,failure to Test EDG IAW TSs Were Noted.Caused by Inadequate Application of TSs When Initial Surveillance Procedures Were Being Developed.Condition Rept on Potential Issue Was Written on 980207
05000425/LER-1998-003-03, :on 980508,lightning Strike Leads to Turbine Reactor Trip.Caused by Main Generator Trip.Spare step-up Transformer Was Placed Into Service & Unit Was Returned to Power on 980514
05000334/LER-1997-011, :on 970509,determined Inadequate Testing Was Performed on Solid State Protection Sys Relays K630A & K630B.Caused by Inadequate Procedure.Subject Relays Tested & Verified Operable & Revised Procedures
05000334/LER-1998-003, :on 980128,failure to Perform Chemical Addition Sys Valve Cycling Surveillance as Required by TSs Occurred. Caused by Inadequate Application of Tss.Test Procedures 1OST-13.11 Was Revised
05000259/LER-1999-001-01, :on 990115,inoperable CR Emergency Ventilation Sys During Post Maint Testing Was Noted.Caused by Failure of Procedure Writers & Reviewers.Returned a Crev to Operable State & Revised B Crev Train Procedures.With
05000498/LER-1999-002-01, :on 990327,inadequate Performance of TS Surveillance When Evaluating Source Range Nuclear Instrument Discriminator Bias Curve Results,Was Discovered.Caused by Lack of Process to Incorporate Info.Compared Bias Curves
05000324/LER-1990-018-02, :on 901123,HPCI Steam Leak Detection Channel B Logic Blew & HPCI Sys Manually Isolated.Probably Caused by Blown Fuse & Loose Wire.Relay & Fuse Replaced