05000456/LER-1989-014-05, :on 891030,inadvertent Safety Injection Occurred on Train B During Installation of Card Holders. Caused by Personnel Error Design Deficiency.Sys Mod Request Submitted
05000457/LER-1990-010-02, :on 900609,reactor Trip Occurred During Plant Startup from Low Steam Generator Water Level.Caused by Malfunctioning Bypass Feedwater Regulating Valve.Operator Training Provided
05000456/LER-1990-007-04, :on 900601,during Removal of Ohmmeter Probe, Operator Touched Probe to Exposed Terminal Point,Resulting in Automatic Start of Auxiliary Feedwater Pump 1A.Caused by Methodology Deficiency.Probes Modified
05000456/LER-1988-012, Advises That LER 88-012-00 Withdrawn.Investigation Revealed That Operator Did Indicate That Room Temps Less than Tech Spec Limits
05000455/LER-1987-019, Forwards Corrected LER 87-019-00.LER Originally Issued W/ Error in LER Number in Codified Field (Block 6)
05000455/LER-1986-001, Errata to LER 86-001-00,incorporating Page 4 Inadvertently Omitted from Original LER Re Crosby Relief Valve JO-25WR
05000456/LER-1989-008-09, :on 890905,Sargent & Lundy Engineers Evaluation Determined That W/Uncorrected Setpoints,Allowable Tech Spec Value Would Have Been Exceeded.Caused by Unclear Design Documents.Analysis of Setpoints Performed
05000456/LER-1989-004-04, :on 890306,auxiliary Feedwater Pumps Started Automatically Following Closure of Governor Valves.Caused by Defective Test Switch.Stable Plant Conditions Established. Temporary Procedure Changes Initiated
05000456/LER-1989-009-05, :on 890902,failure of Main Steamline Safety Valve to Reseat Occurred.Caused by Preservice Error in Design of Valve.Vendor Recommended Upgrade Will Be Installed on Valve 1MSO17C.Remaining Valves Checked
05000456/LER-1989-003-05, :on 890302,control Room Ventilation Actuations Due to Momentary Loss of Voltage to Radiation Monitors. Caused by Perturbation of 345 Kv Sys.Evaluation Performed on Area & Process Radiation Monitors
05000456/LER-1989-005-06, :on 890422,instrument Inverter 111 Tripped & Repair Not Completed within 24 H Per Tech Spec.Caused by Shorted Capacitor Due to Normal Wear.Instrument Bus Energized & Inverter Repaired
05000456/LER-1989-007-08, :on 890810,containment Bldg Fuel Handling Incident Area Radiation Monitor Went Into Alert Alarm & Interlock Actuation Due to Loss of Pulses.Caused by Failed High Voltage Power Supply in Monitor
05000457/LER-1989-001-09, :on 890223,loss of RHR 2B Loop Occurred as Result of Procedural Deficiency.Caused by Failure to Identify That Placing Ssps in Test Would Not Block auto- Closure of Pump Valves.Procedure Revised
05000456/LER-1989-001, :on 890206,reactor Trip Occurred Due to Spurious Loss of Output Voltage on Instrument Inverter 112. Cause of Momentary Loss of Inverter Under Investigation. Feedwater Isolation Signal Reset
05000456/LER-1989-002-09, :on 890416,main Steam Line Low Pressure Reactor Trip,Safety Injection & Main Steam Isolation Occurred.Caused by RCS Pressure Above 1,1930 Psig & Main Steam Pressure Less than 640 Psig.Heatup Procedure Will Be Revised
05000457/LER-1989-003-01, :on 890322,centrifugal Charging Pump 2B Manual mini-flow Isolation Valve Mispositioned.On 890601, Recirculation Flow Read Zero.Caused by Personnel Error. Locked Equipment Program Will Be Revised
05000456/LER-1989-006-09, :on 890718,lightning-induced Voltage Transients Experienced,Resulting in Actuation of Multiple Rod Drive Overvoltage Protection Devices.Caused by Inadequate Lightning Protection.Protectors Reset
05000456/LER-1988-002-04, :on 880125,reactor Trip & Safety Injection Generated During Performance of Instrument Surveillance Analog Operational Test & Channel Verification/Calibr.Caused by Personnel Error.Test Rept Revised
05000456/LER-1987-057, :on 871009,as Throttle Valve 2 Being Cycled, MW Output Became Erratic Resulting in Reactor Trip.Root Cause Indeterminate.Temporary Instrumentation Installed on Sensing Line of Turbine Impulse Transmitter
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
05000454/LER-1987-018-03, :on 870811,reactor Trip Occurred.Caused by Trip of Main Feedwater Pump Due to Broken Wire on Proximity Probe.Feedwater Supervisory Instrumentation Repaired & Calibr & Automatic Trips on Pumps Disabled
05000454/LER-1987-019-03, :on 870812,safety Injection & Reactor Trip from Low Steam Line Pressure Occurred Due to Failed Main Turbine Throttle.Caused by Failed Moog Servo Valve.Valve Replaced & Procedures Revised
05000455/LER-1987-006-01, :on 870427,reactor Tripped Due to Pressurizer Pressure Spiked Below Reactor Trip Setpoint.Caused by Failure of Pressurizer Pressure Transmitter & Nuclear Loop Power Supply on Channel 456
05000455/LER-1987-007, :on 870504,reactor Tripped During Performance of Quarterly Power Range Calibr Surveillance on Channel NI-43(IG).Caused by Trip of Bus 211 Due to Failure of Wornout Capacitor.Inverter Repaired & Tested
05000455/LER-1987-011-08, :on 870725,reactor Tripped on Overtemp Delta T Condition.Caused by Inability of Plant Secondary Side to Remove Heat Generated by Primary Side & Controller Inability to Accept Large Load Reject in Valve Mode
05000454/LER-1987-017-03, :on 870729 & 31,de-energization of Power Supplies in Rod Drive Sys Caused Reactor Trips.Caused by Lightning Strikes.Power Supply Overvoltage Protection Circuits Reset & Verified Operable
05000455/LER-1987-012-07, :on 870730,2B Diesel Generator Failed to Reach Rated Speed within Required Time Limit.Caused by Instrument Drift of Pressure Indicator.Faulty Indicator & Turbocharger Replaced & Air Regulator Correctly Set
05000454/LER-1987-022-03, :on 871026,area Radiation Monitor Spiked Above Alert Alarm Setpoint,Resulting in Containment Ventilation Isolation Alarm.Caused by Faulty Detector.Detector Replaced & Monitor Returned to Svc on 871029
05000455/LER-1987-001-01, :on 870115,during Initial Criticality/Low Power Physics start-up Test Requiring Bistable Trip,Reactor Trip Occurred.Caused by Reactor Coolant Resistance Temp Detector Splice Failure.Splice Connection Corrected
05000457/LER-1989-003-10, :on 890322,discovered Mispositioning of Centrifugal Charging Pump 2B Manual Mini Flow Isolation Valve.Caused by Personnel Error.Valve Immediately Opened. Independent Verification Program to Be Revised
05000455/LER-1987-009-08, :on 870629,manual Reactor Trip Initiated Due to 2C (Turbine Driven) Main Feedwater Pump Trip.Caused by Cold Solder Joint on Capacitor in Speed Control Feedback Loop. Solder Joint Repaired & Tested
05000455/LER-1987-010-07, :on 870701,manual Reactor Trip Occurred Due to Electrohydraulic Pump Manual Trip Necessitated by Fluid Leak.Caused by Vibration.Supply Line to Fullers Earth Filter Removed & Valve & Nipple Installed
05000454/LER-1987-011-01, :on 870415,carbon Dioxide Sys to Auxiliary Feedwater Pump Room Declared Inoperable.Caused by Vapor Pilot Valve Mispositioned,Closed & Not Included on Design Documents.Valve Opened & Placed on Drawings
05000455/LER-1987-016, :on 870831,during Surveillance Test,Inadvertent Train a Safety Injection Occurred.Caused by Personnel Communication Breakdown.Prof Program Will Be Covered W/ Operating Dept for 6 Wks
05000456/LER-1989-001-07, :on 890206,momentary Loss of Output Voltage on Instrument Inverter 112 Caused Reactor Trip Signal Due to Intermediate Range High Flux Bistable from Channel N36 Reverting to ESF Safe Configuration
05000457/LER-1988-011-01, Withdraws LER 88-011-01 Re Reactor Shutdown as Result of Valve 2SI89089B Declared Inoperable Due to non-environ Qualified Motor.Addl Info Submitted Proved Motor Was Environ Qualified to Required Stds & No Shutdown Required
05000455/LER-1987-017-05, :on 870903,main Steam Isolation Bypass Valve Returned to Svc W/O Completing Required post-maint Testing. Caused by Cognitive Personnel Error.Training on Proper Completion of Checklist Will Be Given
05000454/LER-1987-021-03, :on 870917,control Room Ventilation Actuation Occurred Due to Distribution Sys Voltage Transient When Offsite Line Tripped.Mods Installed in 1985 to Reduce Undervoltage Trip Setpoints on All Process
05000454/LER-1987-020-03, :on 870902,contractor Assigned Continuous Fire Watch Left Assigned Watch Area to Rept for Whole Body Count Processing.Caused by Cognitive Personnel Error.Personnel Given Sheet Listing Responsibilities
05000457/LER-1988-025, :on 880926,verified That Monthly Target Axial Flux Difference Surveillance Not Performed.Caused by Personnel Error.Calculated New Target Values for Delta 1, Updated Curve Book & Processed Computer
05000455/LER-1987-015-07, :on 870829,feedwater Isolation Actuation on Steam Generator Level high-2 Occurred.Caused by Personnel Error.Personnel counseled.Color-coding of Instruments to Prevent Error Under Investigation
05000454/LER-1987-016-05, :on 870831,inadvertent Train a Safety Injection Occurred During Surveillance Test.Caused by Personnel Error. Disciplinary Action Given to Involved Nuclear Station Operators
05000455/LER-1987-008-08, :on 870606,containment mini-purge Supply & Exhaust Ventilation Sys Simultaneously Put Into Operation. Caused by Personnel Error & Procedural Inadequacy.Personnel Involved Disciplined & Procedure Changed
05000455/LER-1987-013-07, :on 870819,deviation from FSAR Description Not Reported within One Month as Required by License Condition 2.C.3.Caused by Personnel Error.Memo Emphasizing Need for Notification of FSAR Deviations Issued
05000455/LER-1987-014-06, :on 870824,primary Containment Type B Local Leakage Rate Tests of Equipment Hatch Airlock Door Gasket Interspaces Not Performed,Making Airlock Inoperable.Caused by Personnel Error.Surveillance Performed
05000455/LER-1987-020-05, :on 871202,unanticipated Water Discharged Into Primary Sys When Safety Injection Accumulators Discharge Isolation Valves Opened.Caused by Defective Procedure. Procedure Revised to Include Precaution
05000454/LER-1987-015-03, :on 870526,automatic Start of Auxiliary Feedwater Pump Occurred.Caused by Personnel Error. Disciplinary Action Taken & Operator Involved Counseled.W/
05000454/LER-1987-016-03, :on 870526,during Mode 3,both Trains of Containment Spray Additive Sys Discovered Inoperable.Caused by Two Locked Open Isolation Valves Mispositioned Due to Procedural Deficiency.Valve Repositioned
05000455/LER-1987-004-01, :on 870221,permission Given to Adjust Containment Isolation Valve 2PS9357A W/O Initiating Appropriate Limiting Condition for Action Requirement.Caused by Personnel Error.Shift Engineer Counseled
05000454/LER-1986-035, :on 861217,investigation of Possible Part 21 Rept on Cooper Bessemer Ksv Series Emergency Diesel Generators Revealed Nonseismic Switches Had Been Wired Into Engine Overspeed safety-related Trip Circuit
05000454/LER-1986-028-02, :on 861002,reactor Manually Tripped.Caused by Defective Firing Card & Intermittent Failure of Alarm Card. Rod Drive Sys Troubleshot,Responsible Circuit Cards Replaced & Alarm Cleared
05000454/LER-1987-009-05, :on 870408,inadvertent Safety Injection Signal Generated During Reactor Protection Sys Surveillance Testing.Caused by 2 of 4 Coincidence Logic Due to Loose Test Lead.Personnel Cautioned
05000454/LER-1987-012-02, :on 870408,contract Maint Crew Stroked RHR HX Component Cooling Water Outlet Isolation Valve,Causing Surge Tank to Reach Low Level CC Pump Trip.Caused by Communication Breakdown Between Maint Crew & Shift Personnel
05000454/LER-1986-012-01, :on 860327,RPI Surveillance Not Performed within 4 H.Caused by Personnel Error.Bank Demand Vs Digital RPI Surveillance Reinstated
05000454/LER-1984-031-01, :on 841215,boron Dilution Protection Sys Actuated.Caused by Electrical Noise Spikes.Triaxial Cable Connectors Disassembled & Cleaned & Heavier Gauge Grounding Wire Installed on Cabinets
05000454/LER-1984-010, :on 841112 & 19,noise Spikes Occurred on Source Range Channel N31 Resulting in Boron Dilution Protection Sys Actuation.Caused by Personnel Error.Operator Awareness Enhanced & Note Added to Procedures
05000454/LER-1986-026-01, :on 860921,actuation of Control Room Ventilation Occurred.Caused by Lightning Strike on Offsite 138 Kv Transmission Line.Mods Installed in 1985 to Reduce Undervoltage Trip Setpoint
05000454/LER-1984-019-01, :on 841127,boron Dilution Protection Sys Actuated,Resulting in Charging Pump Suction Switchover to Rwst.Caused by Electronic Noise Spike.Triaxial Cable Connectors Disassembled & Cleaned
05000454/LER-1986-007, :on 860212,process Radiation Monitor 0PR34J Went Into Interlock Mode Due to Noise Spike on Monitor Gas Channel.Caused by Bad Edge Component or Connector on Motherboard.Motherboard Replaced
05000455/LER-1986-002-10, :on 861122,digital Rod Position Indication & Bank Demand Step Counters Differed by More than 12 Steps, Requiring Opening of Reactor Trip Breakers.Caused by Defective Detector Encoder Card.Card Replaced
05000454/LER-1987-014-03, :on 870505,mode Change Inoperable Steam Generator Occurred Due to Misplugged Tube.Caused by Personnel Error.Tube Plugged & Verified Correct.Personnel Counseled
05000455/LER-1987-007-06, :on 870504,reactor Tripped During Performance of Quarterly Power Range Calibr Surveillance.Cause of Capacitor Failure Undetermined But Attributable to Normal Wearout.Inverter 211 Replaced
05000454/LER-1987-013-03, :on 870501,reactor Trip Signal Occurred During Control Rod Position Surveillance.Caused by Momentary Loss of Level Simulation Due to Bumping of Simulation Mechanism. Precaution to Simulation Surveillance Added
05000455/LER-1987-006-06, :on 870427,reactor Trip Occurred When Pressurizer Pressure Spiked Below Reactor Trip Setpoint. Caused by Failure of Presssure Transmitter & Nuclear Loop Power Supply During Surveillance Performance
05000454/LER-1986-030-03, :on 861023,sampling Period for Inoperable Radiation Monitor Delayed for 12 H.Caused by Personnel Error,Memo Issued Reemphasizing Notification Procedures.W/
05000454/LER-1986-029-03, :on 861022,480-volt Breaker,Providing Overcurrent Protection for Electrical Penetration Feed to Containment Crane 1HC22G,discovered Not Tested Prior to Entry Into Mode 4.Caused by Personnel Error
05000454/LER-1987-010-05, :on 870419,Tech Spec 3.0.3 Entered Due to Two Trains of Main Control Room Ventilation Being Inoperable. Caused by Drift of High Differential Pressure Switch. Differential Pressure Switch Recalibr
05000454/LER-1987-011-03, :on 870415,auxiliary Feedwater Pump Room Sys Inoperable.On 870416,vapor Pilot Valve Discovered Closed.On 870404,vapor Pilot Valve Demonstrated Open During Inadvertent CO2 Actuation Event.Cause Unknown
05000454/LER-1986-032-02, :on 861208,ESF Response Time Surveillance Discrepancy Noted in Procedure Resulting in Violation of Tech Specs.Caused by Procedure Incorrectly Timing High Steam Pressure Rate Logic Circuitry
05000454/LER-1986-024-02, :on 860725,w/plant in Power Operation Mode 1, Main Control Room Outside Air Intake a Process Radiation Monitor Went Into Interlock Mode.Caused by Noise Spike on Monitor Particulate Channel
05000454/LER-1986-035-02, :on 861217,notice Received of Possible Part 21 Rept Re Cooper Bessemer Diesel Generators.Investigation Revealed That non-seismic Switches Wired Into Engine Overspeed.Caused by Design Error
05000455/LER-1986-003-10, :on 861216,Safety Injection Train 2B Rendered Inoperable by Closed & out-of-svc Safety Injection Pump 2B During Hot Standby (Mode 3).Caused by Cognitive Personnel Error.Mode Change Checklists Revised
05000454/LER-1986-031-03, :on 861121,maint Re Breaking of Nonexempt ASME Code Class 3 Pressure Boundary Strainer Completed & Returned to Svc W/O Required post-maint Visual Exam.Caused by Personnel Error.Visual Exams Performed
05000455/LER-1986-001-11, :on 861120,component Cooling Pumps 2A & 2B Tripped Due to Pressure Spike Caused by Shutdown of Pump 2A. Event Caused by Personnel Error in Setting Relief Valve. Valve Repaired & Reinstalled
05000454/LER-1986-022-03, :on 860703,during Required Shutdown to Mode 5 Due to Excessive RCS Unidentified Leak,Source Range Nuclear Instrumentation Channels Improperly Declared Operable.Caused by Personnel Error
05000454/LER-1986-027-03, :on 860930,reactor Tripped Following Feedwater Isolation & Turbine Trip Due to Damaged Test Cable.Caused by Personnel Error.Damaged Cable Repaired & Temporary Cable Will Be Installed
05000455/LER-1987-001-07, :on 870115,reactor Trip Occurred Due to Reactor Coolant Resistance Temp Detector (RTD) Failure.Caused by Loop C Cold Leg Temp Narrow Range RTD Failing to Low Resistance.Failed RTD Replaced & Recalibr
05000454/LER-1987-002-07, :on 870114,main Control Room Outside Air Intake a Process Radiation Monitor Went Into Interlock Mode Due to Failed Automatic Checksource Test on Iodine Channel. Checksource Positioning Mechanism Realigned
05000454/LER-1987-003-02, :on 870111,equipment Attendant Recorded Failure of Fire Alarm But Failed to Immediately Notify Shift Engineer That Acceptance Criteria Not Met.Caused by Personnel Error.Personnel Counseled
05000454/LER-1987-001-06, :on 870111,radioactive Release Tank Not Sampled Prior to Release Per Tech Spec 4.11.1.1.1.Caused by Personnel Error.Radiation Chemistry Technician Counseled & Tanks Relabeled
05000454/LER-1986-025-02, :on 860826,Tech Spec 3.12.1 Re Radiological Environ Monitoring Not Met.Caused by Personnel Error.Suppl to 1985 Annual Radiological Environ Operating Rept Will Be Submitted
05000455/LER-1987-005-06, :on 870331,reactor Tripped Due to Spurious Actuation of Turbine Motoring Generator Trip Circuitry.Cause Unknown.Differential Pressure Switch Found Out of Tolerance But Unrelated to Event.Switch Replaced
05000454/LER-1987-008-04, :on 870324,Train B Automatically Switched to Safeguards Mode During Switching Process.Caused by Safeguard Signal.Cause of Signal Unknown.Procedures Revised
05000454/LER-1986-034-03, :on 861212,radiation Detector to Train B Found Defective.Detector Replaced.On 861215,discovered Leads Restored to Wrong Terminals.Caused by Personnel Error. Personnel Counseled
05000457/LER-1988-022, :on 880919,reactor Trip Occurred Due to Source Range Channel N31 Exceeding Setpoint of 1.0xE5 Counts Per Second.Caused by Loose Connection in Main Control Room Panel 2PM05J.Investigation Conducted
05000454/LER-1986-033-03, :on 861209,post-maint Visual Leak Test Not Performed,Violating Tech Spec.Caused by Defective Procedure. Project Const Now Working Under Station Nuclear Work Request Program
05000457/LER-1988-021, :on 880915,high Level Alarm Occurred on Steam Generator 2C.Caused by Out of Calibr Positioner for Feedwater Regulating Bypass Valve 2FW530A.Water Level Restored & Work Request Issued
05000456/LER-1988-019-01, :on 880801,Train a & B Control Room Ventilation Automatically Shifted to Emergency wake-up Mode.Caused by Momentary Fluctuation in Line Voltage That Dropped Below 90 Volts.Equipment Operation Returned to Normal
05000456/LER-1988-015-03, :on 880710,control Room Recirculation Charcoal Absorber Dampers Repositioned,Placing Charcoal Absorbers in Svc & Annunciating Control Room Recirculation Alarm.Cause Undetermined.Protective Device to Be Installed
05000457/LER-1988-016-03, :on 880624,facility Reactor Trip Occurred on 2B Steam Generator low-low Level Due to Failue of Heater Drain Tank Makeup Valve.Valve Repaired & No Significant Abnormalities Found
05000454/LER-1986-021-03, :on 860614,performance of RCS Water Inventory Balance Exceeded Tech Spec Action Statement by 1 H & 27 Minutes.Caused by Personnel Misinterpretation of Requirement.Personnel Counseled
05000454/LER-1987-007-04, :on 870316,hourly Firewatch Started Late Thereby Exceeding Requirements of Tech Spec.Caused When Radiation Protection Personnel Issued Neutron Dosimetry to Technician 20 Minutes Late.Personnel Counseled
05000454/LER-1986-016-03, :on 860527,following Installation of Backup Electrical Power Supply,Continuous Fire Watch Inadvertently Released from Post.Caused by Personnel Error.Engineer Instructed on Fire Watch Procedures
05000454/LER-1986-018-03, :on 860602,main Control Room Outside Air Intake Process Radiation Monitor a Went Into Interlock Mode. Caused by Misaligned Check Source Mechanism.Mechanism Realigned
05000454/LER-1987-006-03, :on 870311,monthly Fire Protection Valve Lineup Surveillance Incorrectly Scheduled.Caused by Failure to Consider All Tech Spec Scheduling Requirements.Use of Existing Computer Program Mandated
05000457/LER-1988-029, :on 881025,manual Reactor Trip & RCS Inventory Balance in Excess of Required Time Interval Occurred.Caused by Condensate Pump Suction Strainers Plugging.Main Condenser Thoroughly Inspected & Cleaned
05000456/LER-1988-022-02, :on 881016,reactor Tripped on Reactor Coolant Pump Low Flow Followed by Turbine/Generator Trip.Caused by Potential Transformer Failure on Offsite 138 Kv Line.Subj Potential Transformer Replaced & Line Restored
05000454/LER-1987-005-04, :on 870310,contractor Personnel Inadvertently Damaged Fire Protection Sprinkler Head.Sus Isolated & Declared Inoperable.Caused by Procedural Deficiency. Formalized Training Provided
05000457/LER-1988-026, :on 880923,when Second Phase of Data Collection Attached,Turbine & Reactor Trip Occurred.Caused by New Type of Configuration & Lack of Proper Communications Between Personnel.Test Equipment Removed
05000455/LER-1987-004-06, :on 870221,shift Control Room Engineer Missed Tech Spec Action Requirement on Containment Isolation Valves.Valve Discovered Inoperable for 62 H.Caused by Personnel Error.Personnel Involved Counseled
05000457/LER-1988-025-01, :on 880926,monthly Target Axial Flux Difference Surveillance Not Performed,Resulting in Exceedance of Tech Spec Limit.Caused by Cognitive Personnel Error.New Target Values for Delta I Calculated
05000454/LER-1987-004-05, :on 870225,safety Injection Occurred During Maint Troubleshooting.Caused by Personnel Error.Disciplinary Action Taken Against Personnel Involved & Other Instrument Maint Personnel Counseled
05000457/LER-1988-023-01, :on 880919,Trains 2A & 2B Declared Inoperable. Caused by Inadequate Venting Due to Surveillance Data Sheets Not Providing Complete Guidance & Inadequate Review of Surveillance.Procedures Changed
05000455/LER-1987-003-05, :on 870217,both Trains of Essential Svc Water Makeup & Two Out of Three Trains of Nonaccessible Auxiliary Bldg Exhaust Ventilation Inoperable in Excess of Tech Specs Time Limits Due to Personnel Error
05000454/LER-1986-023-03, :on 860718,discovered Installation of Defective Pressurizer Safety Valve as Result of Excessive Seat Leakage on 860717.Caused by Series of Personnel Errors.Secure Storage Cages Constructed
05000454/LER-1986-020-02, :on 860702,RCS Leakage Exceeded Tech Specs. Caused by Failed Packing Diaphragms on Isolation Valve. Entire Valve Cut Out & Replaced
05000454/LER-1986-012-02, :on 860327,4 H Surveillance of Digital Rod Position Indication Vs Bank Demand Position Indication Mistakenly Stopped.Caused by Personnel Error.More Specific Instructions on Daily Orders Instituted
05000454/LER-1986-019-03, :on 860630,discovered That power-range Nuclear Instrumentation Channel Not Fully Tripped within 6 H of Declaring Channel Inoperable.Caused by Personnel Error. Procedures Revised
05000454/LER-1986-002, :on 860126 & 0204,w/plant in Mode 1,process Radiation Monitor OPR31J (Main Control Room Outside Air Intake a) Went Into Interlock Mode Due to Spike on Monitor Iodine Channel.Caused by Bad Component
05000454/LER-1986-010-03, :on 860318,w/plant in Mode 1,main Control Room Outside Air Intake B Process Radiation Monitor OPR34J Went Into Interlock Mode Due to Loss of Sample Flow.Caused by Sample Pump Shutdown Due to Bumping Switch
05000454/LER-1986-017-03, :on 860602,both Trains of Main Control Room Ventilation Sys Inoperable.Caused by Setpoint Drift on Train a Makeup Fan & Bent Spring Release on Train B Supply Fan Breaker.Setpoint Recalibr & Spring Repaired
05000454/LER-1986-004-01, :on 860131 & 0205,outside Diameter Auxiliary Bldg Charcoal Booster Fan Automatically Started W/O Proper Signal.Caused by Failure of Westinghouse AR-3 Relay in Fan Breaker Closing Circuitry.Leads Moved
05000454/LER-1986-015-03, :on 860507,discovered Test Voltage for Verifying Neutron Flux Multiplication for Boron Dilution Protection Sys Incorrect.Caused by Inadequate Procedures. Interim Procedure SPP-86-71 Written
05000454/LER-1986-014-03, :on 860512,main Control Room Outside Air Intake Process Radiation Monitor a Went Into Interlock Mode.Caused by Clogged Particulate Sample Filter.Filter Interval Changed
05000454/LER-1985-091, :on 851009,auxiliary Bldg Charcoal Booster Fan Automatically Started.Output Contact from Energized Unit 2 ESF Relay Not Properly Isolated from Unit 1 Associated Equipment.Caused by Installation Error
05000457/LER-1988-009-05, :on 880530,manual Reactor Trip Due to Inoperable Rod Control Sys.Caused by Failure of Miscellaneous Electric Room (Mer) Ventilation Fan.Temporary Cooling Fans Installed in Mer
05000457/LER-1988-030, :on 881030,steam Generator Water Level Reached hi-hi Level Due to Overfeeding.Caused by Nuclear Station Operator Lack of Experience.Steam Generator Water Levels Restored to Normal Band
05000456/LER-1988-024-04, :on 881031,operator Noted That Hydraulic Pump on 1A MSIV Pumping Continuously.Caused by Failure of M1 Four Way Valve.Nuclear Work Request A26531 Written to Replace Defective Four Way Hydraulic Valve M1
05000457/LER-1988-031, :on 881105,reactor Trip Due to Negative Rate Trip on All Instrumentation Sys Power Range Channels Occurred.Caused by Incorrect Relay 1H Setting Due to Conflicting Info in Technical Manual
05000454/LER-1986-013-03, :on 860423,containment Air Lock Leakage Rate Surveillance Performed Late Due to Misapplication of Tech Spec 4.0.2.Caused by Personnel Error.Computer Program Revised to Require Testing Every 6 Months
05000457/LER-1988-024-02, :on 880921,steam Generator hi-hi Level Due to Incorrect Operation of High Pressure Cleanup Loop Occurred. Caused by Design Deficiency in man-machine Interface. Engineering Evaluation Will Be Performed
05000457/LER-1988-008, :on 880220,inadequate Capacitor Connection Resulted in Degraded Instrument Bus Voltage & Reactor Trip. Caused by Preservice Installation Error of Capacitor by Vendor.Capacitor & Connecting Leads Replaced
05000456/LER-1988-020-02, :on 880916,control Room Train B Ventilation Automatically Switched to Makeup Mode Due to High Radiation Signal.Cause Unknown.Pressure Transducer Replaced
05000456/LER-1988-003-02, :on 880113,fuel Handling Bldg Incident Monitor ORT-AR056 Went Into Alarm Condition Due to Loss of Pulses. Cause Not Known.Detector Cable Slackness Not Considered to Have Caused Loss of Pulses.Monitor Replaced
05000457/LER-1988-020-01, :on 880904,manual Reactor Trip Occurred Due to lo-lo Steam Generator Levels.Caused by Failure of Emergency Drain Valve.Steam Generator Levels Recovered & Stable Conditions Established
05000456/LER-1988-011, :on 880415,0503 & 0506,high Radiation Signals Processed by Control Room Train B Radiation Monitor Caused Control Room Ventilation Sys to Shift to Emergency Makeup Mode.Caused by Noisy Switch.Monitor Reset
05000456/LER-1988-011-01, :on 880415,0503 & 06,control Room Ventilation Sys (VC) Shifted to Emergency Makeup Mode Due to Spurious Monitor Spike.Cause Not Determined.Monitor Reset & VC Returned to Normal.Electrocubes Installed
05000454/LER-1986-005-02, :on 860129,loss of Sample Flow Alarm Occurred & on 860130,radioactive Liquid Release Started.Loss of Sample Flow Alarm Due to Sample Pump Seal Failure.Sample Pump Rebuilt
05000454/LER-1986-004-03, :on 860131 & 0205,auxiliary Charcoal Booster Fan Automatically Started W/O Receipt of Valid Start Signal. Caused by Failure of Westinghouse AR-3 Relay in Fan Breaker Closing Circuitry
05000456/LER-1988-010, :on 880410,control Room Ventilation Sys Automatically Shifted to Emergency Makeup Mode of Operation. Caused by Mgt Deficiency.Setpoint Corrected to Proper Value
05000456/LER-1988-009, :on 880407,discovered That on 880316,using Work Traveler,Control Room Chiller Temp Controller Incorrectly Determinated.Caused by Planning Error by Contractor Mgt. Control Room Chiller Reterminated
05000457/LER-1988-012, :on 880620,shorting Switch on Relay Casing Intentionally Opened as Part of Reading on Phase B Overcurrent Protective Relay Resulted in Voltage Spike. Caused by Defective Test Switch
05000457/LER-1988-014, :on 880622,reactor Trip Occurred as Result of lo-lo Level on Steam Generator 2B.Caused by Low Static Spring Preload,Dirt & Grease Partially Blocking Valve Action.Steam Generator Water Level Restored
05000456/LER-1988-016-06, :on 880811,reactor Tripped Due to Improper Administrative Controls.Caused by Cognitive Personnel Error. Stable Plant Condition Established Following Reactor Trip.W/
05000454/LER-1986-003-01, :on 860129,reactor Trip & Auxiliary Feedwater Actuation Occurred.Caused by Grounded Conditions on Positive & Negative Poles of 125 Volt Dc Bus.Reservoir Mods & Updates to Filling Procedures Planned
05000457/LER-1988-019-02, :on 880724,reactor Manually Tripped Due to Decreasing Steam Generator Levels.Caused by Mispositioning of Instrument Air Isolation Valve in 90% Closed Position. Stated Valves Stroked & Heaters Checked
05000456/LER-1988-018-02, :on 880722,discovered That Surveillance Requirement for Essential Svc Water Isolation Valves Not Performed After Containment Chiller Returned to Svc on 880521.Caused by Procedural Deficiency
05000456/LER-1988-017-03, :on 880721,two Tech Spec Composite Samples Not Included in Program.Caused by Misinterpretation of Amended Tech Spec Requirements by non-licensed Chemist.Correct Interpretation of Tech Specs Verified
05000456/LER-1988-008, :on 880325 & 27,operators Noted Decreasing Vol Control Tank Level Causing Increased make-up.Caused by Improperly Locked Closed Valve Inadvertently Bumped Off Closed Seat.Valve Repaired & Reinstalled
05000457/LER-1988-005-04, :on 880321,component Cooling Water Surge Tank Level Instrumentation Discrepancies Discovered.Caused by Design Organization Error.Mods Initiated to Address Level Switches,Level Indication Cables & Labeling
05000454/LER-1985-101, :on 851227,reactor Tripped Due to High Steam Generator Level.Caused by Lack of Explicit Procedural Identification of Feedwater Flow Control Loop Switch Position Prior to Calibr.Procedure Revised
05000456/LER-1988-014-04, :on 880702,determined That 40 Sequencing Timer for Containment Spray Had Not Been Tested within Tech Spec Time Requirements.Caused by Procedural Deficiency. Procedure Will Be Revised
05000457/LER-1988-018-01, :on 880702,reactor Tripped While Conducting Startup Test Bwsu NR-75A.Caused by Failure of Pressurizer Pressure Bistable 457C.Work Request A23995 Written & Failed Card Replaced by Instrument Maint Dept
05000456/LER-1988-012-05, :on 880611,room Temps for Safety Injection & Centrifugal Charging Pump 1B Not Taken & Contaminated Spill Occurred in Areas of Room.Caused by Personnel Error. Personnel Counseled & Procedure Revised
05000457/LER-1988-015-02, :on 880626,feedwater (FW) Isolation & Turbine Driven FW Pump Trip Occurred.Caused by Sensitivity of Westinghouse Steam Generator D-5.FW Isolation Reset & FW Pump Restarted
05000457/LER-1988-017-01, :on 880629,Surveillance 2BwOS 4.6.2.1.D-1 Invalid.Caused by Calculational Error.Event Reviewed W/ Personnel Involved.Attention to Detail Stressed
05000457/LER-1988-001-11, :on 880305,safety Injection Pump Discharge Valve Locked Closed.Caused by Miscommunication Between Licensed Operator & Second Nonlicensed Operator.Proper Guidance on Use of Log Reviewed W/Personnel
05000456/LER-1988-006-01, :on 880313,partial Loss of Auxiliary Bldg Nonaccessible Filter Plenum Position Indication Occurred. Caused by Adminstrative & Mgt Deficiency.Event Reviewed W/Individuals Involved & Reviewed W/Personnel
05000457/LER-1988-013-04, :on 880621,reactor Trip Occurred as Result of lo-lo Steam Generator Level Due to Insufficient Feedwater Flow to Steam Generator 2A.Caused by Procedural Deficiency. Feedwater Line Restored
05000457/LER-1988-012-03, :on 880620,shorting Switch on Relay Resulted in Voltage Spike & Actuated Instantaneous Overcurrent Protection Relay.Caused by Defective Current Test Switch on Relay.Switch Relay Case Replaced
05000457/LER-1988-011-05, :on 880607,reactor Shutdown Upon Receipt of Notification That Environ Qualification Documents for Motor Operator on RHR Isolation Valve 2SI8809B Could Not Be Found. Motor Replaced
05000457/LER-1988-006, :on 880210,auxiliary Feedwater Pump 2A Auto Started.Caused by Personnel Error.Exit Procedure & Pump Initial Conditions re-established & Operator Retrained in Correct volt-Ohm Meter Application
05000456/LER-1988-013-01, :on 880609,station Chemist Informed That Four Release Tank Samples Missing.Caused by Programmatic Deficiency.Samples Will Be Kept in Locked Storage Cabinet
05000456/LER-1988-007, :on 870215,unit Entered Mode 4,on 880218,pumps 1B,2A & 2B Declared Inoperable Due to Discovery That Lower Motor Bearing Vibration Readings for RHR Not Current.Caused by Programmatic Deficiency
05000457/LER-1988-007-01, :on 880216,reactor Vessel Flange Inner O-ring Leak Detection Manual Isolation Valve 2RC80698 Discovered Closed.Caused by Personnel Error.Sys Configuration Restored to Required Lineup
05000454/LER-1986-006-02, :on 860212,control Room Ventilation Sys Train B Shifted to ESF Actuation on Signal from Control Room Air Intake Monitor ORE-PR033.Caused by Procedural Error During Monitor Filter Change.Checklist Implemented
05000454/LER-1986-007-02, :on 860212,process Radiation Monitor OPR34J Went Into Interlock Mode Due to Noise Spike on Monitor Gas Channel.Cause of Noise Spike Unknown.Troubleshooting Being Performed to Determine Cause
05000454/LER-1986-009, :on 860222,during Cold Shutdown,Containment Vent Isolation Occurred Due to Undervoltage Condition at Radiation Monitors 1RT-AR011 & 1RT-AR012.Caused by Voltage Transient on 345 Kv Distribution Sys
05000454/LER-1985-096, :on 851207,incorrect Containment Pressure Loops Utilized to Fulfill post-accident Monitoring Requirements, Per Tech Spec 3/4.3.3.6.Caused by Personnel Error.Complete Calibr on Loops Performed.Procedure Revised
05000454/LER-1986-011-02, :on 860324,main Control Room Outside Air Intake Process Radiation Monitor B Went Into Interlock Mode Due to High Vacuum Alarm.Caused by Clogged Sample Particulate Filter.Filters on Radiation Monitors Changed
05000454/LER-1986-002-04, :on 860126 & 0204,control Room Ventilation Actuation Occurred Due to Process Radiation Monitor OPR31J Iodine Channel Spike.Iodine Channel High Voltage Power Supply & Circuit Boards Replaced
05000454/LER-1985-050, :on 850505,discovered That Surveillance Requirements for Tech Spec 3.2.5 Not Recorded Every 12 H. Temporary Procedure 85-1-383 Approved Immediately.Facility in Violation of Requirements Since 850224
05000454/LER-1985-090, :on 851009,reactor Tripped Due to False Low Flow Signals from RCS Loop 1D.Caused by Venting Loop Flow Transmitter.Calibr of Reactor Coolant Flow Loop Being Revised to Restrict Work on Transmitters
05000454/LER-1986-008, :on 860217,turbine Generator & Reactor Trips Occurred Due to Phase Differential Current Sensed by Main Transformer.Caused by Ice Buildup on Transmission Line Tower During Ice Storm.Transformer Replaced
05000454/LER-1985-084-01, :on 850924,fire Watch Delayed.Caused by Key Stuck in Vital Area Door Lock.Fire Watch Resumed After Another Security Person Arrived to Attend Door.Lock Repaired
05000454/LER-1985-060, :on 850616,refueling Water Storage Tank (RWST) Water Temp 103 F.Caused by Personnel Error in Not Observing Procedures for Placing RWST Heater Pump in & Out of Svc.New Procedure Being Written
05000454/LER-1985-095, :on 851107,w/unit in Cold Shutdown,Inadvertent Auto Start of Diesel Generator 1A Occurred During Auxiliary Bldg Ventilation Sys ESF Logic Surveillance.Caused by Temporary Procedure.Procedure Revised
05000454/LER-1985-088, :on 850908 & 11,process Radiation Monitors OPR34J & OPR33J,respectively,went Into Interlock Mode.Caused by Noise Spike on Monitor Gas Channels.Train B Ventilation Sys Transferred to ESF Configuration
05000454/LER-1985-081, :on 850731,following Completion of RHR Pump Operability Surveillance,Rhr Sys Declared Inoperable.Caused by Testing Valve Lineup That Allowed Only Two of Four Cold Legs to Be Available During Accident
05000454/LER-1986-001-06, :on 860116,reactor Trip Occurred Due to Ambiguities in Temporary Procedure.Caused by Insufficient Detail in Procedure to Distinguish Between Two Nearly Identical Auto Shunt Trip Test Panels
05000454/LER-1985-086, :on 850829,MSIVs Declared Inoperable.Caused by Environmentally Unqualified Terminal Strips Located in Junction Boxes on Msivs.Strips Removed & Wires Reattached
05000454/LER-1985-093, :on 851027,125-volt Dc Battery Bank & Charger Operability Weekly Surveillance Affecting 111,112 & 125-volt Dc Battery Bank & Charger Not Performed within Required Time Interval.Caused by Personnel Error
05000454/LER-1985-070, :on 850724,during ASME Quarterly Surveillance Test for Train B RHR Pump (1RH01PB),pump Upper Motor Bearing Vibration Exceeded Limits.Caused by Motor Imbalance Placing Force on Motor Runner
05000454/LER-1985-094, :on 851028,process Radiation Monitor Went Into Interlock Mode Due to Check Source Test Failure.Caused by Malfunctioning Iodine Detector.Detector Replaced
05000454/LER-1985-061, :on 850624,reactor Trip Occurred Due to Steam Generator 1A LO-2 Level.Caused by Attendant Inadvertent Activation of Local Overspeed Trip Bar for Feedwater Pump 1C.Trip Lever Handles Removed
05000454/LER-1985-082, :on 850811,waste Gas Sys Samples Not Obtained & Analyzed.Caused by Personnel Error.New Communication & Limiting Condition for Operation Action Statement Handling Mechanisms Implemented
05000454/LER-1985-079, :on 850809,core Axial Flux Difference (Afd) Not Logged Hourly Following Restoration of computer-generated Afd Alarm.Caused by Personnel Error.Afd Monitor Alarm Inoperable Surveillance Procedure Revised
05000454/LER-1985-072, :on 850717,project Engineering Dept Notified Station That All Environmentally Qualified Limitorque Operators,W/Base Lubricant,Unqualified.Base Grease Removed & Replaced W/Calcium Grease
05000454/LER-1985-100, :on 851211,Fire Door D-633 Found Blocked by Electrical Cord by Contractor Const Personnel.Cord Removed & Door Locked.Personnel Attended Retraining Session Re Importance of Fire Protection
05000454/LER-1985-097-01, :on 851208,inadvertent Safety Injection Occurred.Caused by Personnel Procedural Error.Operators Instructed to Independently Verify Steps of Procedure
05000454/LER-1985-080, :on 850806,determined That Tech Spec Surveillance 1BOS 3.1.1-2 Did Not Account for Feedwater Tempering Line Flow.Caused by Omission from Operating Calometric Procedure.Procedure Changed
05000454/LER-1985-098, :on 851209,ESF Actuation of Main Control Room Ventilation Sys Occurred Due to Deenergization of Train a Radiation Monitors.Root Cause of Common Feedbreaker Trip to Monitor Undetermined.Event Terminated
05000454/LER-1985-007, :on 850111,radiation Monitors OPR33J,OPR34J, 1RT-AR012 & ORT-AR056 Went Into Interlock Condition Due to Voltage Transient Caused by Starting of Circulating Water Pump 1B.Undervoltage Setpoint Lowered
05000454/LER-1985-092, :on 851016,during Security Computer Outage, Fire Watch Delayed 20 Minutes Due to Vital Area Door Lock Failure.Caused by Loosening of Set Screw in Cylinder.Lock Will Be Replaced
05000454/LER-1985-083, :on 850820,RCS Water Inventory Surveillance Not Performed within Required Time Interval.Caused by Inadequate Review of Surveillances Listed on Surveillance Schedule. Shift Engineers Reprimanded.Event Reviewed
05000454/LER-1985-067, :on 850711,oxygen Concentration in Waste Decay Tank OD Exceeded Tech Spec 3.11.2.5 Limit of 2%.Caused by Leak in Gas Decay Tank Oa Manual Release Valve.Nuclear Work Request B20396 Written to Repair Valve
05000454/LER-1985-078, :on 850807,during Delta I Calibrs,Reactor Tripped on Power Range High Negative Flux Rate.Caused by Personnel Error.Instrument Maint Dept Personnel Counseled & Surveillance Procedures Revised
05000454/LER-1985-011-01, :on 850111,discovered Safety Injection Trains Feeding Cold Leg Injection Isolated.Caused by Closing of Isolation Valves Due to Concern Re Overpressurizing Rcs. Temporary Procedure Change Request Initiated
05000454/LER-1985-076, :on 850805,radiation Monitor OPR31J Went Into Interlock Mode.Caused by Check Source Test Failure.Work Request Written to Repair Check Source & Monitor Returned to Normal Operating Status
05000454/LER-1985-077, :on 850807,area Radiation Monitor ORT-AR056 Went Into Interlock Mode Due to Voltage Transient.Caused by Starting Circulating Water Pump 1B,resulting in Auto Start of Ob Fuel Handling Bldg Charcoal Fan
05000454/LER-1985-074, :on 850729,automatic Actuation of Fuel Handling Bldg Charcoal Booster Fan Occurred When Power Disrupted. Caused by Operator Error.Caution Card Placed at Breakers & Work Request to Correct Label Written
05000454/LER-1985-075, :on 850801,equipment Hatch Personnel Airlock Leakage Rate Exceeded Tech Spec Limit.Caused by Procedural Inadequacy Leading to Deficient Testing Conditions.Local Leakage Rate Testing Procedures Revised
05000454/LER-1985-073, :on 850722,feedwater Isolation Occurred Due to High Level in Steam Generator 1B.Caused by Surge in Indication Level in Response to Sudden Momentary Drop in Steam Header Pressure & Increase in Steam Flow
05000454/LER-1985-069, :on 850714,reactor Trip & Loss of Automatic Safeguards Actuation on Train B Occurred.Caused by Personnel Error.Power Supplies Reenergized & Solid State Protection Sys Repaired
05000454/LER-1985-071, :on 850717,main Steam Line Isolation Signal Initiated During Steam Generator 1B Testing.Caused by Incorrect Procedure Allowing Redundant Pressure Rate Bistables to Be Tripped.Test Procedure Revised
05000454/LER-1985-068, :on 850713,lightning Strike Resulted in Reactor Trip & Damage to Listed Train B Safeguards Instrumentation. Caused by Induced Voltage Transient on Station Ground & Rod Drive Power Failures.Lightning Sys Mods Made
05000454/LER-1985-066, :on 850712,operating Temp Delta T Trip Setpoint Exceeded During Load Rejection Testing,Causing Reactor Trip & Control Room Ventilation Makeup Fan auto-start.Caused by Inaccurate Stroke Times of Steam Dump Valves
05000454/LER-1985-065, :on 850709,process Radiation Monitor OPR33J Went to Interlock Mode on Two Occasions.Caused by Inadvertent Bumping of Pump Flow Control Switch.Handles to Air Intake Monitors Removed
05000454/LER-1985-063, :on 850708,control Rod P-8 Misaligned.Decision to Trip Turbine Caused Reactor Trip Because Permissive P-7 Not Actuated.Reactor & Turbine Power Below 10%.Impulse Pressure Rescaled
05000454/LER-1985-089, :on 850913,both Trains of Control Room Ventilation Inoperable.Caused by Workers Misreading HVAC Ductwork Drawings.Project Const Dept Will Review HVAC Drawing Conventions W/Personnel Responsible
05000454/LER-1985-062, :on 850627,automatic Reactor Trip Initiated on Overtemp Differential Temp.Caused by Loss of Two Tripped Circulating Water Pumps.Control Circuits Replaced & Separated Into Three Cabinets
05000454/LER-1985-087, :on 850902,four Auxiliary Bldg Sprinkler Sys Did Not Alarm When Tested & 10 H Elapsed Before Surveillance Entered.Caused by Failure of Equipment Attendants to Inform Shift Engineer
05000454/LER-1985-064, :on 850704,voltage Transient Tripped Power Failure Alarm,Initiating Containment Ventilation Isolation. Transient Caused by Start of Circulating Water Pump 1B.Mods Will Be Made to Radiation Monitor Sensitivity
05000454/LER-1985-085, :on 850829,determined That Two ASME Code Class 2 Welds in Safety Injection Sys Not Examined Per ASME Requirements.Caused by Misidentification of Weld for Exam. Relief from Requirements Granted on 850903
05000454/LER-1985-048, :on 850424,radiation Monitor OPR32J in Main Control Room Outside Air Intake a Went Into Interlock Mode, Causing Train a of Ventilation Sys to Transfer to ESF Configuration.Caused by Dirty Filter
05000454/LER-1985-049, :on 850424,Train a Main Control Room Ventilation Sys Transferred to Makeup Mode of Operation. Cause of ESF Actuation Unknown.Ventilation Isolation Restored to Normal Operating Status
05000454/LER-1985-053, :on 850525,reactor Trip Occurred Due to lo-lo Steam Generator Meter Level.Caused by Dirt & Filings Shorting Windings of Transformer in Inverter.Inverter Replaced
05000454/LER-1985-054, :on 850524,reactor Trip Occurred Due to Turbine Trip on Low Auto Stop Oil Pressure.Caused by Fouled Return Line Strainers & Inadequate Overflow Capacity.Insp & Cleaning Program Established
05000454/LER-1985-052, :on 850522,reactor Tripped at 50% Power. Caused by Turbine Trip When Electrical Fault in Unit 2 Sys Auxiliary Transformer Actuated Improperly Set Differential Relay for Unit 1 Main Power Transformer
05000454/LER-1985-051, :on 850521,reactor Trip Produced Due to Turbine Impulse Pressure Greater than 10% W/Turbine Throttle Valves Closed.Caused by Inadequacy in Station Power Ascension Procedure.Procedure Revised
05000454/LER-1985-047, :on 850417,RCS Unidentified Leakage Exceeded Max Allowed Value.Caused by Leakage in Diaphragm Valves in Chemical & Vol Control Sys Letdown Flowpath.Flowpath Removed from Operation & Isolated.Valves Tightened
05000454/LER-1985-058, :on 850519,one Hourly Fire Watch Patrol Not Conducted.Caused by Personnel Assignment Error.Disciplinary Actions Taken.Addl Security Sergeant Assigned to Supervise & Ensure Proper Fire Watch Performance
05000454/LER-1985-057, :on 850528,fire Watch Patrols Restricted from Performing Rounds of Auxiliary Bldg.Caused by ALARA Concerns Due to Gaseous Radiation Release While Venting Vol Control Tank.After Survey,Fire Watches Resumed
05000454/LER-1985-059, :on 850517,hourly Fire Watch Delayed When Two Fire Patrols Combined to Perform Dual Verification of Security Doors.Caused by Security Computer Failure. Self-locking Security Doors Installed
05000454/LER-1985-045, :on 850410,reactor Coolant Sample Taken 7 H & 45 Minutes After Reactor Trip Contrary to Tech Specs.Caused by Personnel Error.Shift Engineer Notified & Sample Collected & Analyzed
05000454/LER-1985-055, :on 850515,containment Floor Drain Isolation Valves 1RF026 & 1RF027 Declared Inoperable When Xomox Valve Manufacturer Reported That Valves Not Seismically Qualified. Brackets Installed on Valves
05000454/LER-1985-046, :on 850421,reactor Tripped Due to Steam Generator Lo-2 Level.Caused by Auxiliary Relay Sticking in Energized Position Producing Isolation of Feedwater Control Valves.Relays Replaced
05000454/LER-1985-056, :on 850515,CECo Engineering Notified Station That Rupture of Common Blowdown Line to Condenser or high-energy Auxiliary Steam Sys Line Could Produce Unacceptably Harsh Environ.Flowrate Reduced
05000454/LER-1984-012-01, :on 841110,five Radiation Monitors Lost Power. Caused by Power Down of non-ESF Electrical Bus.Power Supply Book Revised to Correctly Indicate Electrical Feeds to Monitors
05000454/LER-1985-041, :on 850412,Train B Main Control Room Ventilation Sys Automatically Realigned to Makeup Mode. Caused by Personnel Error.Individual Counseled
05000454/LER-1985-044, :on 850403,discovered Tech Spec Limiting Condition for Operation Action Statement Not Entered for Containment Isolation Valve Maint & Time Test Not Performed. Caused by Staff Error.Procedure Specs Issued
05000454/LER-1985-039, :on 850402,reactor Trip Occurred Due to Steam Generator 1B LO-2 Level.Caused by Loss of Feedwater Flow from Feedwater Pump 1B.Procedure Used for Power Ascension Revised
05000454/LER-1985-042, :on 850329 & 0410,reactor Tripped Due to Four Shutdown Bank a Group 1 Rods Losing Gripper Coil Current & Falling Into Core.Caused by Faulty Circuit Card in CRD Logic Cabinet.Card Replaced
05000454/LER-1985-036, :on 850327,radiation Monitors OPR34J & 1RT-AR012 Went Into Interlock Mode Due to Power Failure. Caused by Voltage Transient Due to Bushing Failure on Offsite Transformer
05000454/LER-1985-043, :on 850410,fire Watches in Auxiliary Bldg Suspended for 3 H Due to Evacuation.Caused by ALARA Concerns Following Rupture of Boric Acid Evaporator Rupture Disk.Area Surveyed by Health Physics Personnel
05000454/LER-1985-040, :on 850319,control Room Ventilation Sys Tech Spec Limiting Condition for Operation Action Statement Not Entered within Required Time Limit When Train a Process Radiation Monitor Not Available
05000454/LER-1985-038, :from 850117-0331,CO2 Fire Protection Sys Valve Alignment Not Verified Per Tech Specs.Caused by Surveillance Coordinator Error.Surveillance Coordinator Instructed to Check Failed Surveillances
05000454/LER-1985-032, :on 850314,low Pressure Feedwater Heater Nonreturn Check Valve 14C Discovered Improperly Installed. Caused by Const Installation Error.Valve Reinstalled Correctly
05000454/LER-1985-035, :on 850314,during Plant Recovery Following Loss of Offsite Power Test,Safety Injection Occurred Due to Low Steam Line Pressure.Caused by Operational Condition of Plant
05000454/LER-1985-037, :on 850323,while Plant Operated in Mode 5,main Control Room Outside Air Intake Radiation Monitor OPR33J Went Into Interlock Mode.Caused by Dirty Particulate Filter. Filters Now Changed Daily
05000454/LER-1984-033-03, :on 841218,26,30,850102 & 10,gas Monitor Channels on Radiation Monitors OPR34J & OPR33J Went Into High Radiation &/Or Interlock Alarm,Due to Externally Generated Noise.Cause of Noise Unknown
05000454/LER-1984-032-03, :on 841221,fire Penetration W/Four Conduit Pipes Discovered Improperly Sealed.Cause Not Stated. Penetration Sealed & Fire Watch Established
05000454/LER-1984-031-04, :on 841215,17 & 19,boron Dilution Protection Sys Actuated.Caused by Electrical Noise Spikes on Nuclear Power Source Range Channels.After Origin Determined,Operator Realigned Charging Pump Suction to Line Up
05000454/LER-1985-028, :on 850304,reactor Tripped Due to Manual Turbine Trip.Caused by Abnormally Fluctuating Generator Output.Training Dept Will Emphasize That Turbine Power May Vary from Generator MW Output
05000454/LER-1985-034, :on 850318,during MSIV Operability Test, Operator Accidentally Actuated Manual Safety Injection Handswitch Instead of Manual Main Steam Isolation Handswitch.Operators Reminded to Read Labels
05000454/LER-1984-034-03, :on 841227,discrepancy in Number of Sources Received on 841221 Discovered.Caused by Rad/Chem Technician Comparing Package Contents to DOT Sticker Instead of Packing List.Procedures Being Revised
05000454/LER-1985-033, :on 850314,particulate Filter & Iodine Cartridge Collected from Auxiliary Bldg Vent Stack Monitors 1RE-PR028 & 2RE-PR028 Not Analyzed as Required by Tech Spec Table 4.11-2.Caused by Personnel Error
05000454/LER-1984-030-03, :on 841218,instrument Bus 111 Deenergized & Boron Dilution on Protection Sys Actuated Due to Deenergization of Nuclear Instrumentation Channel I.Caused by Shorted Capacitor in Control Circuitry
05000454/LER-1984-042-02, :on 841031,data Sheet Incomplete for Surveillance 4.7.10.3.1 Not Accounting for electro-manual Pilot Control for Valve.Caused by Typo.River Screen House CO2 Sys Walked Down & Procedure Revised
05000454/LER-1985-025, :on 850301,emergency Trip Header Low Pressure Reactor Trip Surveillance Not Performed within Required Interval Prior to Reactor Startup.Caused by Surveillance Schedule Program Not Listing Applicable Mode
05000454/LER-1984-025-04, :on 841213,reactor Trip Occurred Due to Instrumentation Calibr of Turbine Impulse Pressure Channel. Caused by Procedural Error.Instrumentation Calibr Surveillance Procedure Revised
05000454/LER-1985-023-01, :on 850227,automatic Safety Injection Actuation Occurred.Caused by Improper Calibr of Digital electro- Hydraulic Controllers & Valve Interlocks.Valve Positions Recalibr
05000454/LER-1984-028-03, :on 841207,gas Monitor Channels of Radiation Monitors OPR32J & OPR36J Went Into High Radiation & Interlock Alarm.Apparently Due to Externally Generated Electrical Noise.Alarms Reset
05000454/LER-1984-027-04, :on 841212,21 & 22,main Control Room Outside Air Intake Gas Monitor Channels OPR32J,OPR33J,OPR36J Received High Radiation & Interlock Alarms During Filter Change.Caused by Noise at Controllers
05000454/LER-1984-023-04, :on 841208,during Digital Rod Position Indication Surveillance,Single Control Rod in Control Bank D Moved Out of Core.Caused by Reversed CRD Mechanism Coils. Wiring Corrected
05000454/LER-1984-029-02, :on 841205,VC Sys Makeup Fan Automatically Started & Sys Switched to Makeup Mode.Caused by Trip & Interlock Actuation of Process Radiation Monitors Being Serviced.Monitors Restarted & VC Sys Restored
05000454/LER-1984-024-04, :on 841129,both Radiation Monitoring Sys CRT Displays in Control Room Became Inoperable,Resulting in Loss of Indication & Alarm for Monitors W/O Dedicated Monitors. Caused by Particulate Buildup on Filters
05000454/LER-1984-026-04, :on 841202,boron Dilution Sys Blocked for Longer than Tech Spec Limits.Caused by Channel N31 Being Out of Svc & Channel N32 Being Blocked for Trouble Shooting of Noise Spikes for 63 Minutes
05000454/LER-1984-022-05, :on 841129,boron Dilution Protection Sys (Bdps) Actuations Occurred Four Times Because of Surveillances on Source Range Instruments.Caused by Bdps Not Blocked. Surveillance Revised
05000454/LER-1984-018-06, :on 841128,HVAC Outside Air Vent Fan Started During Filter Change.Caused by Monitor Tripping During Filter Change.Procedures Revised So Filter Changes Will Not Cause Radiation Monitors to Trip
05000454/LER-1984-021-05, :Between 841127 & 1203,main Control Room Process Radiation Monitors Failed Automatic Check Source Tests,Causing Ventilation Sys to Switch to ESF Mode.Caused by Insufficient Tolerance in Setpoints
05000454/LER-1985-019, :on 850128,monthly Surveillance of Containment Isolation,Containment Radioactivity,High Radiation Monitors Not Performed at Required Interval.Action Statement of Limiting Condition for Operation Entered
05000454/LER-1985-018, :on 850204,fire Protection Detectors Discovered to Be Inconsistent W/Layout Prints & Tech Specs. Caused by Ae Error Due to Oversight.Fire Watch Established & Tech Specs Revised
05000454/LER-1984-019-05, :on 841127,boron Dilution Protection Isolation Sys Actuated.Caused by Noise Spike on Source Range Channels. Westinghouse Requested to Investigate Means of Filtering Out Noise Spikes
05000454/LER-1985-017, :on 850119,PORV Block Valves Not Deenergized During RCS Leak Test.Caused by Misinterpretation of Tech Spec Limiting Condition for Operation.Personnel Briefed
05000454/LER-1985-016, :on 850124,reactor Trip Occurred.Caused by Instrument Mechanic Grounding Strip Chart Recorder Connector Using Incorrect Size for Connectors.Surveillances Performed to Verify Proper Operation of Trains
05000454/LER-1985-012, :on 850117,Tech Spec Surveillance for Steam Generator Blowdown Containment Isolation Valves Found Past Critical Date Re Valve 1SD005C.Caused by Testing of Improper Valve on 850108.Surveillance Program Modified
05000454/LER-1985-015, :on 850131,five Valves Found Outside of Acceptable Lift Setting Range.Caused by Const Activity Adjacent to Safety Valves.Valves Adjusted to Proper Setting
05000454/LER-1985-013, :on 850124,position Indication Test for Valve 1SI8809A Outside of Surveillance Interval.Caused by Omission of Valve from Revised Safety Injection Sys Position Indication Test Surveillance.Procedure Revised
05000454/LER-1985-011, :on 850111,both Safety Injection Trains Feeding Cold Injection Isolated.Caused by Personnel Error.Dept Heads Notified of Importance of Procedural Adherence & Changes
05000454/LER-1985-005, :on 850111,daily Surveillance of Diesel Generator 2A Not Performed.Caused by Personnel Error. Surveillance Performed & Licensed Operators Reminded to Perform Required Surveillances on Schedule
05000454/LER-1985-006, :on 850106 & 10,while Venting Containment to Reduce Internal Pressure,Both Containment Mini Purge Supply & Exhaust Lines Opened in Violation of Tech Specs.Caused by Use of Wrong Procedure
05000454/LER-1984-020, :on 841125 & 28,source Range Channel N32 Indicated Noise Spikes on Four Occasions,Resulting in Containment Evacuation Alarms.Cause Under Investigation. Source Range Channel Modified
05000454/LER-1985-001-02, :on 850103,auxiliary Bldg Vent Stack Monitor Tripped Due to Filter Loading.Caused by Personnel Error. Particulate Filter Collected from Monitor But Not Analyzed as Required to Meet Tech Specs
05000454/LER-1985-009, :on 850108,main Steam Line Isolation Caused by Technician Performing Work on Incorrect Steam Pressure Channel.Plant Operation Unaffected.Event Discussed W/ Technician & at Instrument Dept Meeting
05000454/LER-1985-008, :on 850104,reactor Trip & Auxiliary Feedwater Actuation Occurred Due to Steam Generator lo-lo Alarm. Operators Inadvertently Allowed Level to Drop in Steam Generator While Engaged in Shift Turnover
05000454/LER-1984-003-01, :on 841107,signal Spiking Seen on Both Source Range Channels.Caused by Electrical Noise Generated by or Induced Onto Sys.Source Range Channel Modified & Cleaned
05000454/LER-1984-040-02, :on 841225,reactor Trip Breakers Manually Opened Due to Greater than 12-step Difference Between Digital Rod Position Indication & Demand Step Counters. Caused by Stuck Step Counter
05000454/LER-1984-039-03, :on 841225,radiation Monitor OPR33J Loss of Sample Flow Alarm Caused Control Room Ventilation Sys to Switch to Makeup Mode.Caused by Operator Prematurely Stopping Ventilation Purge.Operator Counseled
05000454/LER-1985-004, :on 850102,during Mode 5,component Cooling Sys Surge Tank Level Rapidly Decreased Due to Const Personnel Unbolting RHR Sys HX Flange.Caused by Improper Review of out-of-svc Procedures
05000454/LER-1984-021-02, :on 841127,main Control Room Ventilation Sys Switched to ESF Mode.Caused by Main Control Room Process Radiation Monitors Failing Automatic Check Source Tests Due to Insufficient Tolerance in Check Setpoints
05000454/LER-1985-003-01, :on 850111 & 12,reserve Offsite Transmission Circuits Unavailable & Periodic Surveillance of Remaining Circuits Not Performed.Caused by Personnel Error
05000454/LER-1984-038-03, :on 841231,control Room Ventilation Sys Switched to make-up Mode of Operation.Caused by Spurious High Radiation & Interlock Alarm on Radiation Monitor OPR34J.Noise Suppression Devices Installed
05000454/LER-1984-035-03, :on 841226,control Room Ventilation Train B Makeup Air Filter Unit Fan Started W/O Automatic Start Input Signals.Caused by Bumped Control Switch.Guardrails Installed to Prevent Inadvertent Starts
05000454/LER-1985-002, :on 850109,gas Monitor Channels on Radiation Monitor OPR33J Went Into High Radiation.Caused by Externally Generated Electrical Noise.Source of Noise Spike Unknown. Investigation Underway
05000454/LER-1984-036-03, :on 841226,diesel Generator 1B Inoperable W/ Centrifugal Charging Pump 1B Operable.Caused by Personnel Error.Personnel Involved Reminded to Verify Plant Status When Making Equipment Inoperable
05000454/LER-1984-013-06, :on 841128,during Surveillance Testing,Fuel Oil Level Reduced to 93.5%,below Tech Spec 93.8% Limit. Caused by Running Diesel Generator for 64 Minutes.Storage Tanks Refilled & Procedures Revised
05000454/LER-1984-020-06, :on 841125 & 30,while in Mode 5,containment Evacuation Alarm Occurred.Caused by Source Range Channel N32 Noise Spikes.Work Underway to Suppress or Eliminate Source Range Noise Spikes
05000454/LER-1984-017-07, :on 841123,train a Safety Injection (SI) Actuated.Caused by Operator Placing Main Control Board Safety Injection Switch in Incorrect Position.Addl Training Re Protection Sys Initiated
05000454/LER-1984-015-07, :on 841125,auxiliary Bldg Vent Stack Monitor Inoperable & Gas Grab Sample Missed.Caused by Personnel Error.Control Room Personnel & rad-chem Foremen Required to Verify Action Prior to Sampling Termination
05000454/LER-1984-014-06, :on 841121,12 H Grab Samples from Process Monitors Not Obtained Per Tech Specs.Caused by Personnel Error.Tighter Administrative Controls Implemented
05000454/LER-1984-016-06, :on 841121,during insp,125-volt 1E Batteries Declared Inoperable.Caused by Battery to Rack Spacing Exceeding Manufacturer Physical Seismic Test Parameter Limit.Spacers Added to Gap
05000454/LER-1984-008-07, :on 841115,fire Watch in Diesel Storage Tank Rooms Terminated Before Fire Protection Foam Sys Reestablished.Caused by Poor Communication.Fire Watch Established & Sys Returned to Svc
05000454/LER-1984-010-08, :on 841112,boron Dilution Protection Sys Actuated.Caused by Noise Spike Due to Pulling Fuse.Mod to Boron Dilution Protection Sys Being Designed
05000454/LER-1984-004-08, :on 841108,process Radiation Monitor ORE-PR031B for Oa Control Room HVAC Outside Air Intake Failed.Train Ob Started
05000454/LER-1984-009-08, :on 841116,auxiliary Bldg Vent Stack Monitor 1RE-PR028 Tripped Due to Filter Loading.Particulate Filter & Iodine Cartridge Not Analyzed within 48 H Because of Lack of Instructions from Lab Foreman to Technician
05000454/LER-1984-011-06, :on 841108,all Communications W/Radiation Monitor OPR31J Lost in Control Room.Caused by Two Terminals Accidentally Shorting During Repairs.Work Request Written & Damaged Components Replaced
05000454/LER-1984-006-07, :on 841109,control Room HVAC Sys Unable to Maintain Positive Pressure.Caused by Operation of Auxiliary Bldg HVAC in Abnormal Lineup.Auxiliary Bldg HVAC Sys Restored to Normal Lineup
05000454/LER-1984-001-08, :on 841104,hourly Fire Watch Patrol Not Executed in Areas W/Degraded Fire Barriers.Addl Instruction Re Staffing for Fire Watches Provided to Security Supervisors
05000454/LER-1984-007-08, :on 841110,11 & 12,grab Samples Not Taken. Caused by Personnel Error.Personnel Counseled on Importance of Taking Samples as Required by Tech Specs
05000454/LER-1985-030, :on 850313,during up-power Maneuver to 10%, Steam Generator narrow-range Level Decreased to 4% Above lo-lo Setpoint.Caused by Low Feedwater Suction Pressure.Automatic Bypass Mod in Progress
05000454/LER-1985-031, :on 850308,reactor Trip Occurred Due to Steam Generator 1B lo-2 Level.Caused by Trip of Feedwater Pump 1B During Investigation of Lube Oil Problem.Instruments Recalibr
05000454/LER-1984-002-08, :on 841106,surveillance Requirements Not Performed to Record RHR Train Flow & Operability.Caused by Operator Oversight & Improper Review by Shift Supervisory Personnel.Personnel Cautioned
05000454/LER-1985-029, :on 850305,reactor Trip Occurred Due to Trouble Shooting by Instrument Maint Personnel.Caused by Personnel Error.Training Class for Technicians Re Reactor Trip Logic Will Be Conducted
05000454/LER-1984-003-08, :on 841107,during Initial Core Loading,Signal Spiking Seen on Both Source Range Channels.Source Range Channels Declared Inoperable.Caused by Electrical Noise on Sys or Induced Onto Sys.Fix Being Investigated
05000454/LER-1985-024, :on 850301,turbine/reactor Trip Occurred.Caused by Inability of Turbine electro-hydraulic Controller to Properly Position Governor Valves to Pick Up Generator Load. Load Vs Valve Position Curve Revised
05000454/LER-1985-022-01, :on 850218,reactor Trip Occurred Due to High Positive Rate on Power Range ex-core Neutron Detector. Caused by Lower Detector on One Channel Failing & Other Channel Being Out of Svc for Testing
05000454/LER-1985-026, :on 850228,radiation Monitor 1PR11J Left Isolated from Containment Atmosphere After Maint Activity on Valve 1PR001B.Administrative Controls Implemented to Ensure Sys Integrity/Proper Restoration After Maint
05000454/LER-1984-041-01, :on 841031,ultraviolet Detector in Zone 38 Failed to Annunciate & Fire Catch Not Initiated Until 841212.Caused by Inoperability of Detector.Replaced Detector Not Proven Operable
05000454/LER-1985-021-01, :on 850217,security Computer Failed,Preventing Hourly Fire Watch.Cause Unknown.Key Will Be Issued to Fire Watch Personnel When Computer Access Cannot Be Obtained
05000454/LER-1985-020-01, :on 850215,spurious Safety Injection Actuation Occurred.Caused by Maint on Pressure Channel & Spurious Trip of Second Pressure Channel Believed to Be Caused by Radio. Radios No Longer Allowed within Containment
05000456/LER-1990-008-06, :on 900608,reactor Trip Occurred Due to High Flux Rate Signal from Power Range Nuclear Instrumentation. Caused by Voltage Transient,Resulting from Lightning Striking Containment.Power Supply Reset
05000457/LER-1990-009-04, :on 900604,pressures for Active & Standby Accumulators Identified to Be Below 4,800 Psig Required for Operability.Caused by Component Failure.Four Way Valve & Hydraulic Oil Filter Used for MSIV Replaced
05000457/LER-1990-005-09, :on 900426,discovered That Diesel Generator 2A Starting Air Distribution Sys Tubing Crisscrossed to Cylinders 6L & 9L.Caused by Preservice Mfg Deficiency. Custom-routed Airlines Replaced
05000457/LER-1990-005-08, :on 900416,diesel Generator 2A Speed Oscillations Occurred Due to Defective Resistor.Caused by Failure of One Dropping Resistor in Governor Unit.Resistors Replaced
05000457/LER-1990-006-09, :on 900521,containment Fuel Handling Incident Area Radiation Monitor Failed Automatic Checksource Test Due to Low Count Rate.Caused by Component Failure.Detector Replaced
05000457/LER-1990-008-03, :on 900517,unit at Power Permissive Circuit Actuated on Train a of Solid State Protection Sys.Caused by Procedural Deficiency in That Switch Rotation Not Specified. Procedure Revised
05000457/LER-1990-007-03, :on 900523,pressurizer Pressure Channel 458 Failed Low & Channel 455 Deviated in Excess of Remaining Two Channels.Caused by Defective Wire on Internal Portion of Pressure Transmitter.Transmitter Replaced
05000456/LER-1990-006-04, :on 891204 & 900416,diesel Generator 1B Experienced Slow Start.Caused by Crisscrossed Starting Airlines for Cylinders 6L & 9L.Starting Airlines Reconnected & Verified to Correct
05000457/LER-1990-004-08, :on 900416,diesel Generator 2A Speed Oscillated Prior to Maint Teardown.Caused by Component Failure.Resistors Replaced & Placed on 3-yr Replacement Frequency
05000456/LER-1990-005-07, :on 900413,determined That Pressures for MSIVs a & D Were Outside Acceptance Criteria of Procedure.Caused by Procedural Deficiencies.Procedures Being Revised to Reflect Values of 4,800 Psig to 6,000 Psig
05000457/LER-1990-003-09, :on 900405,inadvertent Train B Safety Injection Initiation Signal Occurred Due to Programmatic Deficiency. Training Developed & Lens Evaluated for Replacement
05000456/LER-1990-003-08, :on 900326,trip Nuclear Instrumentation Bistables Failed to Trip within 6 H Required by Tech Specs. Caused by Personnel Error.Training Will Be Conducted for Operating Personnel.Procedures Revised
05000456/LER-1990-004-07, :on 900328,containment Ventilation Isolation Actuation Occurred.Caused by Perturbation of 345 Kv Transmission Sys as Result of Phase B Insulator Failure. Engineering Evaluation Conducted on Monitors
05000457/LER-1990-002-10, :on 900318,operator Placed RHR 2A Pump on Recirculation for Boron Sample Resulting in Transfer of Pressurizer Inventory to Refueling Water Storage Tank.Caused by Procedural Deficiencies
05000456/LER-1990-002-03, :on 900119,discovered That Flanges Not Added to Procedure 1BwOS, Primary Containment Integrity Verification of Outside Containment Isolation Devices. Caused by Program Weakness.Training Held
05000456/LER-1990-001-04, :on 900112,reactor Tripped During Dc Ground Isolation Activities When Auxiliary Relay Energized,Causing Turbine Governor & Reheat Interceptor Valves to Close.Caused by Increasing Steam Pressure.Valves Closed
05000456/LER-1989-019-04, :on 891219,discovered That Procedure Did Not Adequately Test Response Times for High Steamline Pressure Rate Steamline Isolation Signal.Caused by Deficient Procedure.Procedures Re Response Time Revised
05000456/LER-1989-017-05, :on 891206,gas Detector Channel of Process Radiation Monitor Experienced Spike,Resulting in Alert Alarm.On 891210,spike on Channel Resulted in High Radiation Alarm.Caused by Failed Detector
05000456/LER-1989-018-04, :on 891215,as Lead on volt-ohm Meter Landed, Containment Bldg Fuel Handling Incident Area Radiation Monitor Went Into Alert Alarm & Interlock Actuation.Caused by Procedure Deficiency.Signal Reset
05000456/LER-1989-016-05, :on 891201,RHR Pump Suction Relief Valve Premature Actuation Occurred & Failed to Reseat.Caused by Deficient Work Practices & Pesonnel Error.Maint Procedures Reviewed.Training Conducted
05000457/LER-1989-007-09, :on 891110,w/auxiliary Feedwater Pump 2B Pump Control Switch in Pull Out Per Stated Reasons,Automatic Initiation of Pump Sys Unavailable for 6 Minutes.Caused by Procedural Deficiency.Keys to Be Color Coded
05000456/LER-1987-006-03, :on 870120,4 H Fire Watch Patrol Detained by Radiation Chemistry Personnel Due to Not Signing Latest Radiation Work Permit & on 870131,did Not Start Route.Caused by Personnel Error.Personnel Retrained
05000457/LER-1989-008-10, :on 891228,equipment Attendant Discovered Refueling Water Storage Tank Vent Line Temp Less than 35 F. Caused by Preservice Deficiency.Storage Tank Vent Path Temp Verified at 36 F
05000456/LER-1989-020-04, :on 891223,failure to Verify Safety Injection Accumulator Boron Concentration within Specified Time.Caused by Programmatic Deficiency.Procedure Revised to Include Action Requirement Sheet
05000457/LER-1989-005-10, :on 891002,discovered That Tech Spec Action Statement Was Not Entered When safety-related Bus Was Removed from Svc.Caused by Procedural deficiency.Out-of-svc Procedure Will Be Revised
05000456/LER-1989-013-04, :on 891005,discrepancy W/Design of Steam Generator Blowdown Sys Identified,Minimizing Auxiliary Feedwater Flow Requirements.Caused by Preservice Design Deficiency.Temporary Design Changes Made
05000456/LER-1989-015-04, :on 891020,sample Canisters for Auxiliary Bldg Vent Stack Radiation Monitor Removed & Not Analyzed within 48 H.Caused by Programmatic Deficiencies & Personnel Error. Procedures & Training Programs Revised
05000456/LER-1989-002-01, :on 890416,main Steamline Low Pressure Reactor Trip,Safety Injection & Main Steamline Isolation Occurred. Caused by Mgt & Procedural Deficiencies.Formal Policy on Use of Extra Operator During Startup Developed
05000457/LER-1989-006-10, :on 890314,nonlicensed Operator Placed Eductor 2B Spray Additive Tank Suction Throttle Valve 2CS021B in Locked Open Position.Caused by Incorrect Valve Labeling. Valves to Be Provided W/High Visibility Labels
05000456/LER-1989-012-05, :on 891016,momentary Loss of Power to Fuel Handling Bldg (Fhb) Area Radiation Monitor Caused Fhb Charcoal Booster Fan to Auto Start.Caused by Personnel Error.Fan Secured & Isolation Signal Reset
05000456/LER-1989-010-04, :on 890915,measured Leakrate of Hydrogen Analyzer Containment Isolation Valve Was Larger W/Valve Indicating Closed.Caused by Incorrect Labeling of Coil Leads.Valve Replaced W/Different Model Valve
05000456/LER-1989-011-04, :on 890920,high Head Safety Injection Valve 1SI8801A Not Capable of Being Powered by Operable Emergency Power Source.Caused by Diesel Generator 1A Being Out of Svc. Policy Statement Issued & Program Revised
05000457/LER-1989-004-09, :on 890907,reactor Trip Occurred as Result of Lightning Induced Voltage Transient Affecting Rod Control Sys.Caused by Lightning Striking Containment.Rod Control Sys Devices Reset
05000457/LER-1989-002-10, :on 890511,unit 345 Kv Bus 11 Received Trip Signal from Transmission Substation 177,resulting in Reactor Trip.Caused by Defective Trip Coil.Phase a Trip Coil Repaired & Relay Time Delays Increased
05000454/LER-1984-037-03, :on 841226,gas Monitor Channels of Radiation Monitor OPR34J Went Into Interlock Due to Loss of Vacuum Alarm.Cause Unknown.Alarms Reset Automatically
05000454/LER-1984-005-08, :on 841106-07,block Wall Between Control Room Area & Auxiliary Bldg Discovered Open.Block Wall Penetration Sealed,Control Room Pressure Boundary Walked Down & Two Addl Leaky Penetrations Sealed