05000325/LER-1990-002-01, :on 900127,common Control Bldg HVAC Sys Isolated & Transferred to Recirculation Mode as Result of Spurious Actuation of Chlorine Detector.Sensor Connection Checked
05000302/LER-1989-037, :on 891026,determined That Instrumentation Used to Balance HPI Flow Through Four Injection Lines During Small Break LOCA Inadequate.Caused by Inadequate Review of B&W Guidelines.Flow Instrument Installed
05000285/LER-1993-011, :on 930624,experienced Reactor Trip Due to Loss of Load.Caused by Lack of Proper Job Planning,Lack of Formal Decision Making Process & Incomplete Communications.Training Will Be Provided to Operations Personnel
IA-92-382, Package Consisting of General Records Schedule 23,NRC Manual Chapter Bulletin 0231-30,NRC Manual Chapter 0231, Maint & Disposition of NRC Official Files & Records & Mgt Directive 3.53, NRC Records Mgt Program
05000410/LER-1988-014, :on 880313,reactor Scram & ESF Actuations Occurred.Caused by Equipment Failure Due to Design Deficiency.Transmitter Replaced W/Upgraded Model & Temporary Mod Performed to Bypass Logic for Valves
RC-98-0133, Responds to Violations Noted in Insp Rept 50-395/98-04. Corrective Actions:Need for Adding Applicable Action Statement for Tt & Feedwater Isolation Automatic Actuation Logic as Part of Conversion to Improved TS Will Be Assessed
05000327/LER-1989-017, :on 890613,observed That Auxiliary Control Room Pressurizer Level Indicators Were Indicating High as Compared to Main Control Room Level Indicators.Caused by Improper Calibr.Part 21 Related
05000328/LER-1988-019-02, :on 880407,discovered That Two ECCS Pumps to Be Inoperable,Resulting in Inadvertent Entry Into Tech Spec 3.0.3.Caused by Inadequate Work Control.Plant Procedure for Work Control Revised
05000301/LER-1998-004-01, :on 980424,operations W/Reactor Core Power Level Was in Excess of 1518.5 Mwt.Caused by Failure to Return FT-466V Input Parameter to Off Scan.Input FT-446V Was Removed from on Scan at Approx 1452
05000259/LER-1989-004-01, :on 890209,condensate Storage Tank Decreased from 26.7 Ft to 10.1 Ft.Caused by Mechanical Failure of Condensate Head Tank Heat Trace.Heat Trace on Condensate Head Tank Repaired
05000352/LER-1989-030, :on 890505,determined That Portion of Radiological Environ Monitoring Program Not Conducted in That Milk Samples No Longer Available from Farm.Caused by Personnel Error.New Station to Be Added
05000338/LER-1988-027, :on 881117,discovered That Requirements of Tech Spec 3.3.2.1 Do Not Refer to Testing of ESF Final Actuated Devices.Caused by Interpretation of Requirements. Justification for Continued Operation Written
05000382/LER-1989-009, :on 890504,discovered Discrepancy W/Steam Generator Eddy Current Test Results from Second Refuel Outage.Caused by Personnel Error & Inadequate Administrative Controls.Selection Process Will Be Revised
05000382/LER-1988-030, :Since 881110,number of Discrepancies Have Been Identified in fire-rated Assemblies at Plant.Cause of Events Appears to Be Inadequate Fire Seal Installation & Insp Program During Initial Plant Const
05000277/LER-1989-013-01, :on 890603,required Test for Diesel Generator Cardox Room Smoke Detectors Was Not Performed.Caused by Lack of Effective Method for Communicating Surveillance Test Status to Shift Manager
05000341/LER-1989-015, :on 890707,power Lost to Div I Reactor Protection Sys Bus a Due to Motor Generator Overvoltage Condition.Caused by Single Phase Sensing Potentiometer. Component Replaced W/Fixed Resistor
05000338/LER-1989-015-01, :on 890808,input Error in LBLOCA Analysis for 18% Steam Generator Tube Plugging Licensing Case Discovered. Caused by PCT Above Limit Specified in 10CFR50.46.Reanalysis Performed to Determine Impact
05000382/LER-1989-005, :on 890222,Limiting Condition for Operation Action 3.8.1.1 Not Performed When Component Cooling Water Pump a Temporarily Removed from Svc.Caused by Misapplication of Terms Operable & Operability
05000293/LER-1989-010, :on 890221,loss of Preferred Offsite Power Occurred That Resulted in Automatic Start of Emergency Diesel Generators.Caused by Actuation of Startup Transformer Differential Ground Relay.Cable Replaced
05000277/LER-1989-006-01, :on 890209,NRC Inspector Discovered That Tubing to Torus Air & Nitrogen Purge 18 Inch Containment Isolation Valve Installed W/Inadequate Support.Caused by Deficient Installation & Maint Instructions
05000277/LER-1989-016-01, :on 890722,APRM hi-hi Signal Caused LPRM Detector 4B-40-33 to Spike Upscale.Caused by Output Signal of LPRM Detector Spiking High.Detector Placed in Bypass Position & Scram Signal Reset
05000260/LER-1989-012, :on 890405,discovered That RHR Pump Breaker Not Racked Out as Required.Caused by Written Special Requirements Not Being Transmitted to Shift Personnel Prior to Board Transfer
05000298/LER-1989-023, :on 890522,during Insps,Wall Thickness Below Required Design Min Observed on RHR Loop a Injection Throttle Valve.Caused by Erosion Due to Throttling.Wall Thickness Measurements Performed More Often
05000327/LER-1989-022-01, :on 890722,power Range Excore Detector N-43 on Unit Failed During Operation & Declared Inoperable.Caused by Inadequate Procedure.Surveillance Instruction SI-178 Revised to Correct Deficiencies
05000382/LER-1989-010, :on 890520,determined That Low Recirculation Flow Not Included in Pump Operability Which Resulted in Noncompliance W/Tech Spec 4.0.5.Caused by Miscommunication. Procedures Revised
05000260/LER-1989-009, :on 890411,spurious Spikes on Independent Main Steam Line Radiation Monitors Resulted in Full Scram.Cause for Spikes Undetermined.Welding & Grinding in Area Stopped & Scram & Isolation Logic Reset
05000312/LER-1989-004, :on 890328,plant Main Feedwater Pumps (MFP) Experienced Speed Control Problems.Because of MFP Controller Problems,Integrated Control Sys Response Caused post-trip. Test Program Established to Monitor Pump
05000364/LER-1989-008, :on 890527,reactor Trip Occurred.Caused by Inadequate Procedure for Verifying Proper Insulation After Reassembly of Bearing Oil Piping.New Bearing & Permanent Magnet Generator Stator Installed
05000277/LER-1989-004-01, :on 890320,HPCI Sys Unable to Fulfill Safety Function During Postulated Design Basis Events.Caused by Design Deficiency.On 890330,step Starting Resistors Removed from Power Circuits
05000328/LER-1988-041, :on 881209,discovered That as-installed Instrument Cabinets Supplied by Bailey Meter Co Did Not Meet Seismic Qualification Requirements.Caused by Lack of Two Restraint Bars on Vendor Drawings
05000425/LER-1989-003-02, :on 890309,Tech Spec 3.0.3 Entered.Caused by Shift Supervisor Depressurizing RHR Sys W/O Approved Procedure,Lack of Closed Loop Communication & Inadequate Sys Status Sensitivity by Operations Shift Team
05000341/LER-1987-033, :on 870729,RWCU Containment Isolation Valve Closed Due to High Effluent Temp.Caused by Personnel Error & Failure of Alarms to Annunciate.Operator Disciplined & Investigation Into Alarm Failure Will Be Made
05000482/LER-1987-054, :on 871127,ESF Actuated.Caused by Moisture Induced Corrosion of Electrical Connector on Radiation Monitor Skid.Connector Cleaned & Sealed W/Heat Shrink Moisture Seal
05000213/LER-1987-009, :on 870718,main Steam Safety Valves (MSSV) Failed Lift Pressure Test.Caused by Failure to Address MSSV Lift Pressure Tolerance in SEP Steam Generator Tube Rupture (SGTR) Analysis.Sgtr Analysis Revised
05000336/LER-1987-011, :on 870723,automatic Reactor Trip Occurred. Caused by Low Level in Steam Generator 1.Spray Valve 2-RC-100F Repaired & Pdic 5270 Replaced
05000346/LER-1998-006, :on 980624,loss of Offsite Power Was Noted. Caused by Tornado Damage to Switchyard.Tested & Repaired Affected Electrical & Mechanical Equipment Necessary to Restore Two Offsite Power Sources
05000278/LER-1998-002-02, :on 980504,failure to Meet TS for Rcic,Was Revealed.Caused by Incomplete Procedural Guidance.Various Components Including Trip Tappet,Head Lever & Tappet Guide Were Replaced
05000277/LER-1998-004-01, :on 980606,failure to Meet TS for off-site Source,Was Determined.Caused by Lightning Strike & No Positive Verification That Tap Changer Was operational.3SU Tap Changer Circuitry Was Repaired,Tested & Returned to Svc
05000382/LER-1998-013, :on 980701,IST Valve Surveillances Were Missed. Caused by Inadequate Processing of Info Transferred Between Operations Procedure Group & Programs Engineering.Procedure Revised
05000213/LER-1987-017, :on 871023,fire Watch Left Post Before Svc Water Pump Water Curtain Sys Returned to Svc.Caused by Personnel Error.Review of Incident for Lessons Learned & Upgrades to Station Training Program Performed
05000369/LER-1998-004-02, :on 980619,discovered Missed Auxiliary Hoist Surveillance Prior to Rod Drive Latching.Caused by Inadequate Work Practices.Suspended Drive Rod Latching, Completed Load Test & Resumed Drive Rod Latching
05000423/LER-1998-033, :on 980610,manual ESF Actuation of Motor Driven Auxiliary FW Pumps Was Noted.Caused by Trip of Motor Driven SG FW Pump.Motor Driven FW Pump Impeller Was Replaced
05000259/LER-1987-028-01, :on 871008,unplanned Containment Isolations Occurred.Caused by Inadequate Procedures.Radiation Monitoring Sys & Alarm Response Procedures Revised
05000289/LER-1986-013, :on 861107,failure Declared on as-found Reactor Bldg Integrated Leak Rate Test.Caused by Leakage from Bldg Purge Exhaust Valve Interspace.Second Test Performed & Resultant as-left Bldg Leak Rate Acceptable
05000277/LER-1989-003-01, :on 890207,group 2C Primary Containment Isolation Sys Valve Isolation Occurred Resulting in motor- Operated Feedwater Flush Valves Receiving Signals to Close. Caused by Stated Inadvertent Signals
05000213/LER-1987-008, :on 870625,control Rod 31 Dropped Into Core & Overfeed to Steam Generator 2 Occurred.Caused by Faulty Fuse & Inadequate Maint Procedure,Respectively.Fuse Replaced & Procedure Revised
05000346/LER-1987-011, :on 870906,reactor Tripped from Power Level of 104.5 % High Flux Reactor Sys Signal.On 870907,two Attempts to Place Decay Heat Loop 2 in Svc Resulted in Pressurizer Level Drops of 10 & 6 Inches,Respectively
05000313/LER-1988-009, :on 880922,three Inoperable Snubbers Discovered on safety-related Piping Sys.One Snubber Failed Due to Spec of Undersized Snubber & Other Two Found W/Inadequate Travel Remaining for Thermal Growth
05000321/LER-1989-001-01, :on 890224,isolation of Group 5 Primary Containment Isolation Sys Occurred.Caused by Rapid Filling of Sys Piping When Pump Suction Valve Opened.Procedures Revised
05000260/LER-1988-016-01, :on 881209,unplanned Manual Start of RHR Pump Occurred.Caused by Personnel Error.Labeling of RHR Local Controls Will Be Corrected & Licensed Personnel Will Review Event
05000321/LER-1987-015-01, :on 870827 & 28,main Control Room Environ Control Sys Actuated on Signal from Refueling Floor Area Radiation Monitor,Resulting in 870827 Pressurization.Caused by Faulty Gm Tube.Tube Replaced
05000341/LER-1989-004, :on 890118,HPCI Inoperable Due to Isolation Logic Functioning W/Nonconservative Trip Valve.Caused by Equipment Failure of Master Trip Unit (Rosemont 710 DU) E41-N657A.Instrument Repaired
05000336/LER-1987-004, :on 870202 & 0208,automatic Actuations of Emergency Safeguards Actuation Sys Resulted in Containment Purge Valve Isolations.Caused by Broken Window on Beta Scintillation Detector.Detector Replaced
05000312/LER-1987-033, :on 870529,11 Hourly Fire Watches Required by Tech Specs Missed.Caused by Unexpected Demand on Available Manpower Due to Breakdown in Security Computer Sys.Fire Watch Pool Will Be Established
05000312/LER-1987-030, :on 870529,due to Concurrent Work on Radiation Monitors R15049 & R15050,number of Operable Channels to Trip Reactor Bldg Purge Sys Reduced to Zero.Caused by Cognitive Personnel Error.Personnel Trained
05000266/LER-1998-008, :on 980203,EDG Air Start Motor Solenoid Valves W/Spring Not in Accordance W/Design Occurred.Caused by Use of 275 Psig Solenoid Valve Which Does Not Meet Minimum DC Voltage Available.Solenoid Valves Modified
05000382/LER-1998-004, :on 980304,TS 4.0.3 Condition - CPC Channel Functional Test,Was Concluded from Preliminary CEOG Rept. Caused by Human Error.Cpc Channels A,B & C Were Satisfactorily Tested
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
05000354/LER-1997-022, :on 970910,unplanned Manual Scram Occurred Due to Relay Malfunction in a Phase Main Generator step-up Transformer.Sampled & Tested Oil in Main Steam Generators & Replaced Cooling Fan Control Circuit Relays
05000266/LER-1998-011, :on 980214,missed TS Surveillance of Radiation Monitor Prior to Discharge Occurred.Caused by Failure to Adhere to Procedures Based on Failure to Recognize.Thorough Root Cause Evaluation Performed
05000482/LER-1993-012, :on 930510,reported Unusual Noise Due to Small Frictional Force Release in RCS During heat-up.Implemented Thermal Expansion Monitoring Program in Refuel Viii to Aid in Identification of Locations of Restraint on RCS
05000255/LER-1998-005, :on 980217,actuation of Containment Isolation Occurred.Caused by Inadvertent Containment High Radiation Signal.Plant Status Evaluated & Equipment Lineups Restored
05000413/LER-1998-003-01, :on 980218,omission in Retest Manual Leads to Failure to Perform Required Retest Prior to Restoring Ci Valves to Svc.Retest Manual Will Be Updated to Reflect Specific TS Requirements for Ci Valves
05000413/LER-1998-004-01, :on 980216,missed TS Surveillance on CR Area Ventilation Sys Actuation Instrumentation Noted.Caused by Incorrect Mode Specification Requirements in Affected Ts. Submitted License Amend & Verified TS Are Met
05000325/LER-1999-008, :on 990809,electric Motor Driven & Diesel Driven Fire Pump Concurrent Inoperability Occurred.Caused by Human Performance Error.Diesel Fire Pump Jacket Water Temp Switch Replaced.With
05000364/LER-1998-001-05, :on 980328,manual Reactor Trip Due to Dropped Control Rod K-2,was Determined.Caused by Overcurrent Condition.Crdm Cable & Connectors Associated W/Rod K-2 Will Be Replaced & Rod Will Be Tested During Startup Testing
05000354/LER-1998-001-03, :on 980213,missed HPCI Resulted in Unavailability of Hpci.Caused by Personnel Error.Reactivated Recurring Tasks & Successfully Performed Surveillance Testing
05000281/LER-1999-004-02, :on 981109,EDG Was Inoperable Longer than Allowed by TS Due to Governor Compensation Valve.Root Cause Evaluation Being Performed to Determine How Compensation Valve Became Closed
05000338/LER-1999-006-01, :on 990904,potential for Safegurads Exhaust Flow to Bypass Charcoal Filter,Was Discovered.Caused by Degraded Damper.Plant Issue Rept Submitted for B Train of Savs Flow Rate.With
05000382/LER-1998-007, :on 980317,discovered That No Allowance for Instrument Loop Uncertainity Included in Surveillance for Chilled Water Outlet Temp.Caused by Failure to Consider Instrument Loop Uncertainty.Revised Task
05000382/LER-1998-006, :on 980306,increased Differential Pressure for Feedwater Isolation Valves Occurred.Caused by Failure to Consider All Pressure Source Affecting Mfivs.Admin Controls Have Been Enacted Requiring Entry Into TS 3.6.3
05000245/LER-1997-033-01, :on 970801,unmonitored Airborne Radioactivity Release Paths Were Discovered.Caused by Lack of Adequate Monitoring Program.Placed Low Vol Air Samplers at Areas in Question
05000302/LER-1998-003, :on 980211,loss of Power to Integrated Control Sys Occurred.Caused by Zener Diode Not Adequately Soldered to Printed Circuit Board Trace for Power Supply Monitor. FPC Replaced ICS Power Supply Monitor
05000412/LER-1997-004-01, :on 970911,discovered That Four Containment Isolation Valves Were Not Tested IAW Ts.Caused by Inadequate Mgt Change.Will Revise Licensing Requirements Manual Table 5.1-1 & UFSAR Table 6.2-60
05000298/LER-1987-016, :on 870526,unplanned Automatic Startup of Both Diesel Generators Occurred Due to Momentary Undervoltage Condition.Possibly Caused by Lightning Strike on 69kV Emergency Transformer.Generators Restored
05000341/LER-1987-018, :on 870520,during Troubleshooting of Leakage Discovered in Drywell,Rwcu Inboard Isolation Valve Isolated Twice & Outboard Isolation Valve Once.Caused by Latent Heat Migration in Sys Piping.Valve Repacked
05000414/LER-1986-016, :on 860521,main Feedwater Isolation Occurred. Caused by Insufficient Info Provided by Mfg to Allow Adequate Initial Calibr of Feedwater Control Sys.Sys Tuned & Startup & Shutdown Procedures Revised
05000400/LER-1986-004-03, :on 861107,safety Injection Signal Occurred During Mod Work to safety-related Inverters.Caused by Operator Failure to Recognize That de-energizing Process Cabinets Would Set Off Signal.Safety Injection Reset
05000364/LER-1986-010-01, :on 860804,reactor Tripped During Testing of Solid State Protection Sys.Caused by Faulty Secondary Disconnecting Contacts on Train B Reactor Trip Bypass Breakers.Contacts Replaced as Needed
05000409/LER-1986-024, :on 860719,water Splashed Off Pipe Onto Solenoid Causing Ventilation Header Solenoids to Deenergize. Caused by Blown Fuse 30-2.Fuse Replaced
05000338/LER-1987-005-01, :on 870419,primary Coolant I-131 Dose Equivalent Specific Activity Exceeded 1.0 Mci/G Limit Set by Tech Spec 3.4.8.a Following Reactor Trip.Caused by Minor Fuel Cladding Defects in Reactor Core
05000382/LER-1986-025, :on 861022,reactor Trip Occurred.Caused by Trying to Maintain Steam Generator Levels at Low Reactor Power for Prolonged Period,Following Reactor Trip on 861021. Valve Positioner Replaced
05000382/LER-1986-022, :on 861020,control Room Isolation Occurred. Caused by Degraded Electrical Connection in Barton Model 765 Flow Transmitter.Transmitter Replaced
05000327/LER-1986-059, :on 861231,eight Fire Dampers in Diesel Generator Bldg Identified as Not Being Verified Functional by Visual Insp Every 18 Months.Caused by Personnel Error. Surveillance Instruction SI-233.3 Changed
05000336/LER-1999-011, :on 990823,thermal Reactor Power Limit Was Exceeded.Caused by Lack of Conservatism in Procedures & Alarm Setpoints Used to Limit Reactor Power.Revised Operating Procedures
05000370/LER-1999-003-01, :on 990616,inadvertent Actuation of Turbine Driven Auxiliary Feedwater Pump Occurred.Caused by Inadequate Policy or Directive.Station Directives Will Be Reviewed & Appropriately Revised
05000317/LER-1998-011, :on 980428,prematurely Released Fire Watch Was Noted.Caused by Inadequate Cure Time Communications.Revised Configuration Control Documents.With
05000293/LER-1999-008-02, :on 990805,automatic Scram Occurred While at 100% Power Due to Automatic Turbine Trip.Caused by Malfunction of Moisture Separator Drain Tank a Drain Valve Controller.Level Controllers Replaced.With
05000409/LER-1986-034, :on 861112,containment Ventilation Valves Closed Automatically When Indication on Containment Bldg Immediate Particulate Monitor Spiked High.Caused by Manipulation of Range Switch.Contacts Cleaned
05000413/LER-1999-014, :on 990816,missed Surveillances & Operation Prohibited by TS Was Noted.Caused by Defective Procedures or Programs Inappropriate TS Requirements.Affected Procedures/ Programs Were Revised & Testing Was Performed
05000413/LER-1987-002, :on 870111,unit Shutdown Commenced When Unidentified Reactor Coolant Leakage Greater than 1 Gpm Determined.Caused by Leak in Loop C RTD Manifold Tubing. Leak Repaired & Unit Returned to Power
05000423/LER-1987-003, :on 870114 & 0205,Train B Emergency Diesel Generator Did Not Start within Required 10 During Surveillance Testing.Caused by Inadequate Purge of Air from Fuel Injectors & Low Oil Temp.Maint Performed
05000338/LER-1997-007, :on 970818,NIS High Flux Trip Setpoint Errors Occurred.Caused by Inherent Inaccuracies Associated with Calorimetric Heat Balance at Low Power Levels.High Power Trip Setpoints Were Reduced
05000382/LER-1997-024, :on 970528,emergency Diesel Generator Autostart Occurred Due to start-up Transformer Failure.Implemented Procedures OP-901-311,OP-901-511 & OP-901-513
05000335/LER-1986-008-03, :on 860827,Train B Exhaust Ventilation Fan HVE-9B Became Inoperable When Thermal Overload Relay Spuriously Actuated & Redundant Train a Fan HVE-9A Found Inoperable Due to Oil Tank Level.Causes Not Identified
05000424/LER-1999-002-03, :on 990630,high-energy Line Break Instrument Channels Were Inadequately Calibrated.Caused by Inadequate Surveillance Testing Procedures.Procedure Revs to Add Relay Testing in Progress.With
05000338/LER-1985-029, :on 851228,during Performance of RCS Leak Rate Test,Leak of 1.28 Gpm Noted.Caused by Reactor Vessel Seal Ring Leaks Chemical & Vol Control Sys Pipe Crack.Seal Rings & Pipe Replaced
05000382/LER-1987-001-01, :on 870330,gaseous Waste Mgt Effluent Radiation Monitor Alarm/Trip Setpoint Set Factor of 10 Too High Since Plant Startup.Caused by Personnel Error.Rms,Its Database & Data Base Change Methodology Under Review
05000220/LER-1987-004, :on 870210,discovered That Instrument Control Surveillance Test Not Performed on 870116,per Tech Specs. Caused by Failure to Complete Rev to Test Procedure Prior to Scheduled Test.Procedures Revised
05000483/LER-1999-001, :on 990119,failure to Implement Operating License Amend 106 Requirements within 30 Day Implementation Period Was Discovered.Caused by Programmatic Deficiency. Corrective Actions Implemented in Dec 1998.With
05000414/LER-1986-026-01, :on 860621,feedwater Isolation Occurred Due to Spurious hi-hi Steam Generator Level Signal.Caused by Design Problem Re Transfer from Main Steam Bypass Isolation Valve to Msiv.Procedures Will Be Revised
05000328/LER-1986-010-04, :on 861203,containment Phase B Isolation Occurred During Performance of Surveillance Procedure.Caused by Deficient Procedure.Procedures Re ESF Actuations During Testing Will Be Revised
05000334/LER-1999-002, :on 990121,4 Input Parameters Were Identified Which Underestimated DBA Dose.Caused by non-conservative Concurrent Iodine Spike Radiological Dose Calculation Methodology.Acs Have Been Implemented.With
05000440/LER-1986-026, :on 860618,containment Isolation Valves Closed. Caused by Technician Inadvertently Grounding Power Lead During pre-operational Test.Technician Counseled.Testing Instructions to Include Caution Note
05000461/LER-1999-004, :on 990126,plant Was Operating Outside Design Basis.Caused Because Design for CR Operator Dose Calculation Did Not Consider Single Failure of CR Ventilation Sys. Revised CR Operator Dose Calculation.With
05000281/LER-1986-007-02, :on 860617,reactor Trip Occurred Due to High Level in Steam Generator A.Caused by Failure of Valve FCV-2478 to Close Due to Metal Debris Between Plug & Valve Seat.Metal Debris Removed & Valve Reassembled
05000461/LER-1999-006, :on 990419,values Used for Containment & Drywell Free Vols Found to Be Smaller than Originally Analyzed Due to Inadequate Calculation Control During Initial Plant Const.With 9905517 Ltr
05000414/LER-1998-007-03, :on 981211,mispositioned Thumbwheel on Process CS Circuit Card Caused Inoperability of Overtemperature & Overpower Delta Temp Functions.Caused by Inadequate Program Design.Revised Procedures
05000263/LER-1999-002-01, :on 990329,event Sequence That Results in Available ECCS Being Reduced to Less than That Assumed in Current Safety Analysis.Caused by Failure of Edg.Plant Operating Procedures Revised.With
05000328/LER-1985-002-01, :on 850112,while Operating at 100% Power,Unit Experienced Automatic Reactor Trip from lo-lo Steam Generator Level on Loop.Caused by Failure of Discharge Valve LCV-6-106A on Heater Drain Tank Pump 3
05000324/LER-1999-002-02, :on 990329,reactor Tripped.Caused by Failed Electrical Connections on Vibration Detector for Number 9 Main Turbine Bearing.Vibration Detectors for Main Turbine Number 9 Bearing Replaced.With
05000301/LER-1999-002-01, :on 990323,discovered That Red Channel of SG Pressure Indication Passes Through Fire Zone.Caused by 1983 Modification Oversight.Twice Per Shift Fire Round Has Been Established for Fire Zone Pending Cable Routing Correction
05000245/LER-1986-017-01, :on 860521,during Downpowering of Planned Shutdown,Reactor Pressure Dropped Briefly Then Increased Rapidly to 1,047 Psig,Causing Manual Reactor Scram.Rate Stop Adjustment Screws Replaced
05000334/LER-1999-004-01, :on 990317,inadequate pre-fire Plan Procedure Guidance Resulted in Potential Damage to Charging/Hhsi Pumps.Caused by Inadequate Consideration of Required Operator Actions.Procedure Revised.With
05000382/LER-1999-003-02, :on 990311,determined That Four Containment Vacuum Relief valves,CVR-101,CVR-201,CVR-102 & CVR-202,were Not Tested.Caused by Contractor Supply of Misinformation. Details of Event Discussed with Contractor.With
05000369/LER-1999-001-04, :on 990306,TS SR for Ice Condenser Lower Inlet Doors Was Not Met.Caused by Failure to Recognize That Recorded Valve Was Outside Acceptance Criteria.Mgt Reinforced Expectations for Procedure Performance & Review
05000382/LER-1999-002-03, :on 990225,discovered RCS Pressure Boundary Leakage on Two Inconel 600 Instrument Nozzles.Caused by Axial Cracks Near HAZ of Nozzle Partial Penetration Welds Resulting from Pwscc.Leaking Nozzles Have Been Repaired
05000413/LER-1999-001-01, :on 990215,inoperable Refueling Water Storage Tank Level Channels Resulted in Operation Outside Design Basis.Caused by Inadequate Program Design.Reviewed Procedure & Communication Improvements Between Groups
05000414/LER-1986-028-01, :on 860627,safety Injection Actuated on Low Pressurizer & Main Steam Line Pressure.Pressure Decreased Due to Inadvertent Opening of Porvs.Caused by Procedure Deficiency.Procedure Revised
05000483/LER-1986-026, :on 860707,Tech Spec Surveillance of Large Stationary 125-volt Batteries Not Performed.Caused by Personnel Error.Personnel Reminded of Weekly Surveillance Responsibilities
05000529/LER-1986-040-01, :on 860701,Limiting Condition for Operation 3.0.3 Entered When Both Containment Spray Pumps Rendered Inoperable Due to Lack of Required Surveillance Tests.Caused by Personnel Error.Test sign-off Modified
05000245/LER-1998-001-02, :on 980109,MRP Determined That There Have Been Periods During Power Operation When Backup Pressure Regulator Was Oos.Caused by Inadequate Understanding of Safety Analysis.Evaluation Will Be Performed
05000255/LER-1998-002, :on 980112,potential Challenge to Channel Separation Was Noted.Caused by Inadequate of Temporary Mod. Specific Controls for Future Temporary Configuration Alterations Have Been Incorporated Into Plant Procedures
05000483/LER-1986-004, :on 860307,reactor Protection Sys Logic Actuation Occurred.Caused by Spurious Electrical Noise in Source Range Cables.Personnel Directed to Use Local Grounds for Welding Activities
05000293/LER-1997-019, :on 971104,discovered That Closure of RBCCW Sys Valves Which Isolate non-essential Heat Loads Were Not Translated Into Procedure.Caused by Inadequate Design Control.Performed SE & Revised Procedures
05000327/LER-1986-027, :on 860603,determined That Surveillance Requirements for Diesel Generators Not Performed as Required Due to Circuit Logic.Sys Design Prevents Performance.Tech Spec Rev Request Resubmitted
05000424/LER-1998-007-03, :on 981215,inadequate Surveillances Were Found. Caused by Wiring Error & Improperly Performed Response Time Testing.Wiring Error Corrected & Procedures Changed to Allow Online Testing
05000255/LER-1997-012, :on 971017,deenergized Control Rods While in Power Operation.Caused by Failure of Individual Barriers to Prevent Inadequate Performance.Post Maint Testing Was Performed.Pages 5,6 & 7 of Incoming Submittal Not Included
05000413/LER-1998-018-01, :on 981214,identified That There No Single Procedure That Specifically Verified Response Time for Two SI RT Functions.Caused by Inadequate Procedures.Procedures Will Be Revised &/Or Developed.With
05000213/LER-1997-019, :on 970808,compensatory Sampling Frequency Exceeded W/Rms Determined Inoperable.Caused by Personnel Error Due to Incorrect Interpretation of Ts.Compensatory Sampling to Be Conducted in Time Frame Required
05000346/LER-1997-013, :on 971002,potential Condition Adverse to Quality Rept Documented Failure to Perform Surveillance Test Before TS Surveillance Late Date.Caused by Administrative Error.Missed Surveillance Completed
05000259/LER-1986-008-01, :on 860212,two Events Experienced Re Failure of Air Solenoid Valves,Utilized in Diesel Air Start Sys,To Fully Close.Caused by Corrosion Products Entering Valves from Air Sys Piping.Air Sys Blown Down Daily
05000324/LER-1998-005-02, :on 981123,chlorine Leak Results in CREVS & Suspended Fire Watches,Occurred.Caused by through-wall Perforation in Cast steel/neoprene-lined Piping T Section. Event Review Team Formed to Investigate.With
05000293/LER-1997-026, :on 971206,automatic Scram Was Initiated.Caused by High Reactor Water Level During Power Ascension.Pilot Valve Clip Was Repositioned Inside Bailey Positioner & Valve Was Stroked Smoothly
05000269/LER-1998-017-01, :on 981128,missed Surveillance Was Noted.Caused by Inadequate Work Planning.Operations Mgt Expectations for Performance of Qpt SR Were Communicated to Appropriate Operations Personnel
05000281/LER-1997-004-02, :on 971202,invalid Mstv Indication Results in Manual Reactor Trip W/Esf Actuation Were Noted.Caused by Displaced Open Limit Switch Arms.Open Limit Switch for Mstv a Was Relocated Closer to Valve Position Bar
05000528/LER-1985-073, :on 850915,step Determining RCS (AB) Flowrate Signed Off as Not Applicable.Flowrate Determination Also Missed in Surveillances on 850606 & 0705.Flowrate Verified Satisfactory by Completion of 41ST-12218
05000354/LER-1997-030, :on 971122,inoperability of CAC Sys Vacuum Breaker Isolation Valves Noted.Caused by Failure to Review Accumulator Sizing Calculation.Repaired Subject Valves, Revised Procedures & Updated IST Program
05000302/LER-1998-011, :on 981029,determined That Control Complex Chillers May Have Operated Outside Design Basis.Caused by non-conservative Assumption Used in RB Temp Profile Analysis.Implemented Procedural Controls.With
05000369/LER-1996-005-01, :on 961101,TS Required Shutdown of Both Units Due to Failed Surveillance Test of Vital Battery Evcc.Caused Is Unknown.Replaced & Retested Vital Battery Bank Evcc
05000423/LER-1999-007-01, :on 990518,discharge Filter Associated with Crss Cubicle Sump Pump 3DAS-8A,was Determined to Be Contaminated.Caused by Back Leakage from Contaminated Drains Feeding Into ECCS Pump.Lines Modified.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
05000339/LER-1987-018-02, :on 871221,inadvertent Emergency Diesel Generator (EDG) Start Occurred During Testing.Caused by Personnel Error.Periodic Test Terminated & EDG Secured & Returned to Normal Standby Status
05000423/LER-1999-005-01, :on 990510,failure to Perform Surveillance on RCS Pressurizer Heater Penetration Breakers Was Noted.Caused by Lack of Mgt Support.Required Surveillance of Identified Ten Breakers Was Completed
05000328/LER-1998-002-05, :on 981016,turbine Trip Occurred Followed by Reactor Trip.Caused by Generator Lockout.Mod Being Evaluated to Physically Isolate Relays from Vibration of Transformers & Adding Two of Two Logic for Actuation of Sudden Pressure
05000321/LER-1999-003-01, :on 990507,incorrect Performance of Equipment Clearance Led to Scram on High Reactor Pressure.Caused by Personnel Error.Personnel Disciplined & Improved Procedure.With
05000327/LER-1988-021-01, :on 880523,loss of Operating Train of RHR Sys Occurred.Caused by Opening of Manual Isolation Valve.Train B RHR Pump Stopped by Placing in put-to-lock Condition
05000423/LER-1988-017, :on 880425,4 H Sample Flow Rate Estimate Not Performed Per Tech Spec 3.3.3.10.Caused by Personnel Error. Written Communications Between Depts Required When Directing Another Dept to Comply W/Tech Spec Action
05000424/LER-1998-005-02, :on 980824,surveillance Was Not Performed When DG Was Rendered Inoperable.Caused by Failure to Control Amount of Debris at DG Exhaust.Expectations for Controlling Work on SR Sys Were re-emphasized.With
05000338/LER-1998-003, :on 980804,service Water Supports Surveillance Was Missed.Caused by Personnel Error.Component Supports Were Examined & Found to Be Acceptable.With
05000369/LER-1998-006-02, :on 980812,noncompliance with Ice Condenser TS SR 4.6.5.1b.3 Noted.Caused by Lack of Clear Documentation Re Interpretation of TS SR 4.6.5.1b.3.Submitted TS Amend to Clearly Establish SR & Will Review Ice Condenser TSs
05000334/LER-1997-018, :on 970705,potential for Spurious Seismically Induced FPS Sys Activation Affecting EDG Was Noted.Caused by Deficiency in Original Design.Established Fire Watch
05000334/LER-1997-015, :on 970501,voluntary Entry Was Proceduralized Into TS 3.0.3 by Allowing Bypass of Source Range Channels Input to High Flux Trip.Caused by Misinterpretation of TS 3.3.1.1,Table 3.3-1,Item 6.Changed Procedure
05000445/LER-1996-001-01, :on 960117,Units 1 Inverter IV1PC2 Output Breaker Tripped on Over Current.Caused by Large Tavg -Tref Error Signal Following Restoration of Power to Distribution Panel.Plat Stabilized to Mode 3
05000302/LER-1994-010, :on 941114,discovered That Door Between Control Complex & Bldg Roof Blocked Open for Roofing Work,Resulting in Operation Outside Design Basis.Caused by Personnel Error. Door Immediately Closed
05000364/LER-1987-010-01, :on 871209,unit Shutdown Due to Pressure Boundary Leakage on RCS Loop B Cold Safety Injection Line Between Check Valve & Loop.Caused by Cracked Joint Due to Fatigue.Defective Pipe Section Replaced
05000382/LER-1997-019, :on 970529,non-compliance with TS 3.3.3.6 for Containment Isolation Valve Position Indication Was Noted. Caused by Misinterpretation of Requirements of RG 1.97. Revised Submittal to NRC
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
05000289/LER-1997-006-01, :on 970424,reactor Bldg Fan Motors Unqualified Cable Termination Occurred Due to Incorrect Engineering Guidance.Caused by Personnel Error.Qualifiable Repair of AH-E-1A Fan Motor Termination Was Installed on 970323
05000336/LER-1988-007, :on 880216,plant Entered Mode 3 W/Only One of Two Diesel Generators Operable,Violating Tech Spec Section 3.04.Caused by Personnel Error.Addl Attention Directed to Tech Spec Actions Statements & Mode Changes
05000336/LER-1988-006-01, :on 880218,combined Bypass Leakage Rate Exceeded Tech Spec 3.6.1.2.C Limit.Caused by Debris Lodged in Caged Area of Valve Preventing Plug from Entering Seat. Debris Removed & Seating Surface Cleaned
05000213/LER-1997-004, :on 970219,potential for Fuel Assembly Exceeding Maximum Load Limit Over Spent Fuel Pool.Cause Due to Removing Exclusion for Fuel Assemblies from TS Requirements in 1989.TS Will Be Amended
05000336/LER-1987-013-02, :on 871219,fire Watch Patrol Failed to Conduct Hourly Insp Per Tech Specs.Caused by Watchstander Failure to Releive Position in Timely Manner.Fire Watch Contractor Replaced
05000219/LER-1997-006, :on 970419,reactor Shutdown Required by Control Rod 5% Scram Times Occurred.Caused by Sticking of Viton a Diaphragms in Scram Solenoid Pilot Valves.Diaphragms Replaced
05000364/LER-1997-003-03, :on 970424,failed to Perform Diesel Generator Surveillance Requirements.Caused by Procedural Inadequacy. Changed Shared Surveillance Schedule to Ensure Testing Will Be Performed for Each Individual Unit
05000289/LER-1997-005-01, :on 970410,declared motor-operated Reactor Bldg Purge Valves Inoperable Due to Inadequate Closing Torque. Caused by Deficient Design Analysis.Will Perform Evaluation of Valve Specific Seating Torque Test Data
05000293/LER-1997-007, :on 970401,safeguard Buses Were de-energized Due to Severe Storm.Replacement of Microprocessor Control Units Installed in Voltage Regulating Transformers
05000338/LER-1996-004, :on 960910,identified Seismic Concerns Re Containment Particulate & Gaseous Radiation Monitors.Caused by Personnel Error in Understanding Regulatory Requirements. Performed Review of Design Changes
05000338/LER-1997-003-01, :on 970516,positive Reactivity Addition During Refueling Was Determined.Caused by Personnel Error.Control Room Crews Were Coached on Positive Reactivity Effect of Filling Cavity from R ST When RCS Is Greater
05000323/LER-1985-023-01, :on 850725,unit Entered Hot Shutdown W/O Necessary Surveillance on Some ECCS & Associated Containment Spray Motor Operated Valves.Caused by Personnel Error. Procedure STP V-7B Satisfactorily Performed
05000354/LER-1986-001-01, :on 860215,diesel Generator D Windings & Rotor Extensively Damaged.Caused by Personnel Error.Field Work Package Incomplete,Qc Involvement Informal & Work Not Properly Implemented
05000255/LER-1986-009, :on 860106 & 08,watertight Fire Doors to safety-related Equipment Rooms Found Open.Caused by Personnel Failure to Follow Requirements for Fire Doors. Personnel Counseled
05000348/LER-1996-007, :on 961107,IEEE-279 Requirements Were Not Met for Protection Channel III SG Instrumentation.Caused by Personnel Error.Implemented Administrative Controls
05000387/LER-1984-044, :on 840613,average Rod Scram Insertion Time Required by Tech Spec 3.1.3.4 Not Met for All Rods. Apparently Caused by Poor Control Rod Scram Pilot Valve Performance.Valves Modified
05000528/LER-1985-076, :on 851007,reactor Trip Resulting from Loss of Offsite Power Occurred.Caused While Troubleshooting Plant Multiplexor (Pmux).Switchyard Breakers Hardwired to Bypass Pmux Breaker Control
05000289/LER-1997-002, :on 970129,potential Inability of Startup Feedwater Block Valves to Fully Close Following Main Steam Line Break Occurred Due to MOV Program Weakness.Increased Torque Switch Settings on Valve Operators
05000250/LER-1985-021-01, :on 850722,two Automatic Initiations of Auxiliary Feedwater Sys Occurred Due to Bypass Feedwater Control Valves Malfunctioning.Caused by Moisture in Instrument Air.Actuators Inspected & Cleaned
05000423/LER-1997-008, :on 970124,TS 3.0.3 Action Statement for MSIV Closure Was Entered Due to TS Being Inconsistent W/Msiv Safety Function & Design.Submitted Proposed License Amend Request Ptscr 3-13-95
05000324/LER-1996-003, :on 960317,units Declared Inoperable & Reactor Shutdown of Units Initiated.Caused by Corrosion Induced by Galvanic Coupling of Retainer Bolting.Corroded Bolting Replaced
05000282/LER-1997-003-02, :on 970325,discovered That Afp Will Trip on Low SG Pressure During Complete Loss of Feedwater ATWS Event. Operability Evaluation of Plant Was Performed
05000498/LER-1996-004, :on 961120,unanalyzed Conditions Were Noted Due to Discovery of Two Spare SR Circuit Breakers Not in Seismically Qualified Position.Caused by Failure to Follow Established Procedures.Revised Procedures
05000266/LER-1997-015, :on 970324,control Room Ventilation Sys Declared Inoperable Due to Failures of Backdraft Damper & Vent Duct Access Door.Backdraft Damper,Replaced
05000369/LER-1997-003-02, :on 970326,both Trains of Control Room Ventilation Sys Inoperable Due to Isolated Air Intake Valves.Radiation Monitor Will Be Evaluated to Determine If Changes Are Needed in Design or Maint
05000382/LER-1997-009, :on 970325,discovered Steam Generator (SG) Low Pressure Setpoint Below Ts.Caused by Inadequate Surveillance Procedure.Revised Surveillance Procedure to Require Channel for Each SG to Be Placed in Bypass During Test
05000348/LER-1997-004-01, :on 970318,safety Related 600 Volt Position Sensitive Seismic Qualification Was Not Seismically Qualified in All Positions.Caused by Personnel Error. Operating Procedures Modified
05000336/LER-1997-008-02, :on 970310,repts Review Facility Compliance W/ GL 96-01 for Reactor Protective Sys Received.Caused by Inadequate Program to Ensure Surveillance Procedures Fully Implement TS Requirements.Procedures Revised
05000338/LER-1997-001-03, :on 970312,auxiliary Svc Water Pump Bolts Exceeded Design Basis Allowable Due to Personnel Error. Asw Pumps Were Declared Inoperable
05000213/LER-1997-007, :on 970311,potential for Svc Water Sys Water Hammer Following Loss of Normal Power Was Noted.Caused Because Original Design of Plant Did Not Identify Potential for Water Hammer.Check Valve Was Installed
05000339/LER-1997-001-02, :on 970314,reactor Vessel Level Dynamic Range Indication on a Train Declared Inoperable.Caused by Procedural Error.Revised Calibr Procedures,Normalized a & B Trains & Returned Train to Service
05000259/LER-1997-002-02, :on 970314,inadequate CREVS Surveillance Instruction Was Identified During GL 96-01 Review.Caused by Deficient Procedure.Rev to O-SI-4.2.G-2 Was Made & SI Section Was Successfully Completed
05000364/LER-1997-002-01, :on 961030,inappropriate Interpretation of Penetration Room Filtration Sys Power Supply Requirement Occurred.Caused by Personnel Error.Revised Interpretation of TS 3/4.9.13 Requirements
05000289/LER-1996-001, :on 961112,investigation of Seismic Qualification of Class 1E 4160 W Breakers Was Conducted Due to Incident Caused by Personnel Error.Racked Out Breakers Were Removed from Associated Modules
05000237/LER-1985-044-04, :on 851213,discovered Power Cable to Diesel Generator 2/3 Cooling Water Pump Damaged & Generator 2 Tripped When Brought Offline.Caused by Use of Conduit as Support When Climbing Ladder
05000334/LER-1997-003, :on 970220,identified RCS Pressure Isolation Valves Were Not Tested.Caused by Operator Error.Affected Valves Declared Inoperable & Verified to Be Closed & Deenergized & Procedures Revised
05000298/LER-1985-013, :on 851022,automatic Closure Emergency Transformer Power Supply Challenged W/Plant in Shutdown. Caused by Inadvertent Opening of 125-volt Dc Feeder Breaker. Breaker Reclosed.Electrical Lineup Established
05000245/LER-1997-012-01, :on 970214,discovered Seismic Deficiency in Gas Turbine Generator Digital Control Sys.Caused by Inadequate Interface Review During Installation of Digital Control Sys in 1987.Implemented Physical Mod
05000499/LER-1997-002-01, :on 970215,Steam Generators 2A Eddy Current Insp Results Fell Into Category C-3.Caused by Stress Corrosion Cracking at tube-to-tube Support Plate.Sg Tubes Were Plugged in Four Unit 2 Steam Generators
05000424/LER-1997-003, :on 970213,unlatched Doors on MCC Changed Seismic Qualifications.Caused by Failure to Maintain MCC Doors Secured.Mcc Doors Were Secured as Necessary
05000259/LER-1997-001-03, :on 970203,potential Overpressurization Containment Penetration Pipe Occurred Due to Thermal Expansion of Entrapped Water Was Identified.Plant Procedures Will Be Revised
05000289/LER-1997-001-02, :on 970117,potential Overpressurization of Piping Between Closed Reactor Building Containment Isolation Valves Occurred Due to Inadequate Design Code Guidance. Results of Review Will Be Documented.Pages 2 & 3 Corrected
05000354/LER-1996-026-01, :on 961108,ESF Actuation/Single Rod Scram Occurred Due to Stuck Scram Solenoid Pilot.Sspv Replaced & CR 42-07 Returned to Svc
05000370/LER-1996-005-07, :on 961109,automatic Start of 2B EDG Due to 6 Kv Switchgear 2TD Bus Lockout,Resulting in 2ETB Blackout. Cause Unknown.Relay Replaced & Will Be Analyzed to Determine Cause
05000321/LER-1996-014, :on 961106,incorrect Circuit Breaker Setting Resulted in Inoperable Edg.Caused by Failure to Incorporate Design Info Into Appropriate Plant Single Line Electrical Drawing.Temporary Plant Mod Will Be Installed
05000369/LER-1996-004, :on 961010,incorrectly Calibrated Rcl Loss of Flow Reactor Trip Bistables Identified.Caused by Procedural/ Technical Inaccuracy.All Affected Procedures Were Changed & Instruments Calibrated within TS Limits
05000346/LER-1997-002, :on 970122,identified Potential Overpressurization of Penetrations During Accident Conditions.Plant Mods & Procedure Changes Being Developed to Prevent Overpressurization of Piping
05000346/LER-1997-001, :on 970122,nuclear Instrumentation Declared Inoperable & Incapable of Performing Safety Functions.Caused by Small Shift in Degraded Bottom Linear Amplifier.Power Range Bottom Linear Amplifier Replaced
05000321/LER-1997-001-01, :on 970129,pressure Boundary Leakage Results in Condition Prohibited by Tss.Cause of Event Cannot Be Determined Conclusively.Maint Personnel Repaired Line.W/
05000446/LER-1996-007-01, :on 961018,reactor Trip Occurred Due to Loss of Reactor Coolant Pump.Caused by Loss of Electrical Bus 2A3. Meter & Relay Technicians (Utility non-licensed) Tested All Relays & Relays Tested Satisfactorily
05000382/LER-1996-009, :on 960726,valves Failed to Pass Leakage Test. Caused by Excessive Roughness in Valve Body Core.Replaced Valves CVR-402A & CVR-402B & Retested Both Valves Successfully
05000364/LER-1997-001, :on 970113,nuclear Instrumentation Sys Inaccuracies Were Below 50% Power.Caused by Personnel Error. Unit Operating Procedures Have Been Modified to Specify That Nis Must Be Adjusted
05000313/LER-1996-009-02, :on 961017,discovered Fire in Reactor Bldg. Caused by Cracked Weld in Oil Line on Reactor Coolant Pump Motor.Extinguished Fire,Replaced Damaged Insulation & Repaired Cracked Weld
05000302/LER-1996-022, :on 961122,operation Outside of 10CFR50 App R Design Basis Occurred.Caused by Design Error.Will Perform Top to Bottom Exam of post-fire Shutdown Analysis & Implement Appropriate Modifications
05000528/LER-1985-041, :on 850705,essential Air Filtration Units for Control Room & ESF Pump Rooms Declared Inoperable Due to Improper Sampling Procedures.Caused by Tech Spec Requirements Not Being Met
05000445/LER-1996-008, :on 961017,two Pressurizer Safety Valves Were Found with Unsatisfactory Lift Setpoints.Caused by Setpoint Drift.Valves Were Returned to Operable Status Using Normal Rework for Components
05000425/LER-1996-006-02, :on 961014,reactor Trip Occurred Due to Main Feedwater Regulating Valve Closure.Mfrv Positioner Was Replaced & Valve Was Returned to Service
05000301/LER-1997-001-01, :on 970107,containment Liner Clearance Was Not IAW Plant Design Basis.Caused by Void Between Containment Liner & Concrete Containment Structure.Inspected Containment
05000266/LER-1997-002, :on 970109,potential to Overpressurize Piping Between Containment Isolation Valves Occurred.Caused by Original Design Not Providing Overpressure Protection for Piping.Review Completed
05000348/LER-1996-006, :on 961008,Kaowool Fire Barrier Sys on Six Unit 1 Raceways Did Not Comply with Program Requirements. Caused by Personnel Error.Hourly Fire Watches Established & Will Remain Until Sys in Compliance
05000414/LER-1997-002, :on 970107,new Incore Fission Detector Was Installed in Unit 2 Reactor & 43 Days Had Elapsed Since Last Survey.Caused by Inadequate Procedural Guidance.Procedure Revised
05000293/LER-1985-020, :on 850726,operations Personnel Notified by Chemistry Group That Emergency Diesel Fuel Oil Storage Tank a Test Results Did Not Meet Tech Spec Criteria.Caused by Personnel Error & Procedural Inadequacy
05000266/LER-1997-001, :on 970108,safety Injection Delay Times Exceeded Design Basis Values.Caused by Degraded Voltage Conditions.Licensee Engineers Will Prepare FSAR Change Requests to Reflect LBLOCA Evaluation
05000293/LER-1996-010, :on 961003,TS Required Composite Analysis Were Not Always Performed for Neutralizing Sump Discharges.Caused by Programmatic Deficiency.Interim Measure Will Be Incorporated Into Procedures 7.9.2. & 7.9.5
05000412/LER-1997-001, :on 970106,reactor Trip Occurred Due to Main Transformer Ground Protection Relay.Caused by Inadequate Design Implementation.Procedures 2OM-35.3C & 2OM-35.4L Revised
05000414/LER-1997-001, :on 970103,maint Found Nitrogen Supply Isolation Valves for Power Operated Relief Valve (PORV) 2SV-1 Closed.Caused by Poor Work Practices.Nitrogen Isolation Valves for 2SV-1 & 2SV-13 Opened
05000446/LER-1996-006, :on 960918,automatic Reactor Trip Occurred. Caused by Lightning Strike.Design Change Was Implemented to Eliminate Ground
05000354/LER-1996-029-01, :on 961228,unplanned Reactor Core Isolation Cooling Sys Inoperability Occurred Due to Stuck Governor Valve.Valve Stem Was Replaced & RCIC Sys Was Returned to Service on 961230
05000334/LER-1996-013, :on 961130,failure to Perform Gaseous Waste Disposal Sys Oxygen Testing as Required by TSs Discovered. Caused by Operator Error & Inadequate Operating Logs. Oxygen Analyzers Were Restored
05000416/LER-1985-028, :on 850717,diesel Generator Tripped.Plant Shutdown Initiated.Caused by Failed Generator Bearing. Bearing Replaced.Generator Returned to Svc Prior to Required Shutdown
05000293/LER-1996-004, :on 960409,low Voltage Power Containment Electrical Penetrations with Degraded Electrical Protection Occurred.Caused by Unawareness of Coordination Requirements. Circuits Breakers Replaced
05000483/LER-1996-008, :on 961223,missed TS 4.8.2.1.a Surveillance of 125-VDC Batteries Due to Cognitive Personnel Error. Individual Involved Has Been Counseled on Importance of Attention to Detail & Self Checking
05000382/LER-1985-028, :on 850627,DNBR & Local Power Density Trip Generated,Resulting in Actuation of Reactor Protective Sys. Caused by Control Element Assembly Position Deviation.Ler to Be Emphasized During Operator Training
05000336/LER-1996-038-02, :on 961202,inadequate Surveillance Procedure Used to Verify EDG Operability.Caused by Failure to Properly Incorporate TS SRs During Recent Revs of Monthly EDG Tests. Changed EDG Surveillance Procedures
05000282/LER-1996-019, :on 961127,spent Fuel Storage Racks Outside Design Basis Due to Boraflex Degradation.Boric Acid Has Been Placed in Immediate Vicinity of Spent Fuel Pool in Event Manual Addition Is Required
05000461/LER-1996-018, :on 961014,incorrect Torque Value for Control Rod Drive Hydraulic Control Units Was Specified by Supplier. Caused by Lack of Attention to Detail.All Hold Down Bolts on CRD HCUs Were Replaced
05000461/LER-1996-019, :on 961120,inadequate Surveillance Procedures Were Noted Due to Misinterpretation of TS Bases Results in Source Range Monitor Reactor Period Display Not Verified. Procedures CPS 9031.13 Will Be Revised
05000327/LER-1996-010-01, :on 961116,manual Reactor Trip Occurred.Caused by Unexpected Feedwater Heater Isolation.Informed Personnel of Effects Changing Proportional Band on Operating Range of Associated Valve Controllers
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
05000413/LER-1985-043, :on 850622,manual Reactor Shutdown Initiated Following Automatic Trip of Main Feedwater Pump Turbine 1B Due to Loss of Condenser Vacuum.Caused by Personnel Error. Incident Discussed W/Personnel
05000309/LER-1996-037, :on 961114,leaking P-29C Gland Cooling Check Valve Was Observed.Caused by Sticking Check Valve in Gland Cooling Water Supply Line to Pump.Affected Check Valves Have Been Replaced
05000483/LER-1985-030, :on 850617,pressurizer Vapor Sample Outer Containment Isolation Valve Not Tested within Required Tech Spec Frequency Extension Limits.Caused by Personnel Error. Personnel Counseled
05000285/LER-1996-012, :on 961111,potential for Vaporizing Cooling Water in Containment Fan Cooling Units Occurred.Caused by Loop Coincident with Loca.Analyses Have Been Performed
05000425/LER-1996-005-02, :on 960925,pressurizer Safety Valve Were Found to Be Open at Pressures Above Setpoints.Caused by Drift in Valves.Worn Bellows & Spindles Were Replaced,Psvs Were Readjusted Valves Were reinstalled.W961024 Ltr
05000352/LER-1985-022, :on 841129,during Fire Damper Insp,Two Reactor Enclosure Fire Penetrations Discovered Unsealed.Caused by Failure to Reinstall Seal After Const Activities.Fire Watch Established.Conduit Penetration Seals Replaced
05000382/LER-1996-011-01, :on 960820,CR Normal Ventilation Isolation Valves (HVC-101 & HVC-102) Were Leaking.Caused by Debris Which Accumulated Inside Valves Disc Regions.Valves Were Closed
05000423/LER-1996-035-01, :on 960920,motor Operated Valve Performance Found Outside Design Basis of Plant.Caused by Inadequate Design & Verification of Actuator.Mov Calculations Will Be Revised
05000263/LER-1996-009-01, :on 960924,failure to Perform Required Actions within One Hour Following Discovery of Water in Fire Hydrant Barrel Noted.Water Was Pumped Out & Drain Port Was Repaired Under Work Orders 9602567 & 9602627
05000413/LER-1985-041, :on 850613,main Feedwater Pump Trip Resulted in Manual Reactor Trip.Caused by Pump Recirculation Valve Not Capable of Modulating Quickly During Flow Reduction.Design Deficiency Corrected
05000271/LER-1993-002, :on 930114,discovered That TS Required Monthly Surveillance Test on Steam Jet Air Ejector Not Completed within 38 Days.Caused by Inadequate Training.Surveillance Testing Control Procedure Will Be Revised
05000369/LER-1985-012-01, :from 850214-0425,fire Doors Normally Locked Closed Were Unlocked & Not Verified Closed Daily Nor Was Fire Watch Posted.Caused by Administrative/Procedural Deficiency.Required Surveillance Implemented
05000334/LER-1992-010-01, :on 921019,while Restoring Motor Operated valves,WR-P-1A auto-started & Immediately Shutdown.Caused by Low Sys Pressure.Maint Work Request Initiated to Check Transmitter Calibr
05000369/LER-1985-016-01, :on 850508,discovered That Temp Compensation Chart Not Incorporated in Hydrogen Analyzer Operation Emergency Procedure.Caused by Procedural Deficiency.Temp Compensation Charts Incorporated in Procedure
05000327/LER-1992-018, :on 921026,reactor Tripped Due to Turbine Trip. Caused by hi-hi Feedwater Level in SG 3 & Failure in automatic-manual Switching Relay.Unit Stabilized in Hot Standby & Relays Replaced
05000344/LER-1992-035, :on 921221,power Operated Relief Valve & Block Valve Protection Indicator Alarms Channel Functional Tests Not Performed Due to Personnel Error.Surveillance Requirements Added to Procedures
05000325/LER-1996-010-01, :on 960813,load Side Conductors Installed on EDG 1 Normal DC Control Power Breaker 8 Were Improperly Secured.Cause Not Known.Edg 1 Normal DC Control Power 8 Load Side Conductors Were Properly Terminated
05000328/LER-1996-002-05, :on 960822,discovered Failure to Properly Identify Steam Generator Tube May Have Exceeded Tech Spec Plugging Criteria.Caused by Misjudgement by Two Independent Analysts.Evaluation Performed
05000339/LER-1985-006-01, :on 850426,unit Tripped from 100% Power When 120-volt Ac Vital Bus 2-I Inadvertently Deenergized.Caused by Misidentification of Power Supply Cabinet & Subsequent Opening of Power Supply Breaker to Inverter
05000423/LER-1996-002-02, :on 960310,inadequate Surveillance for Determining Shutdown Margin When Unisolating Rcl Identified. Caused by Inadequate Procedure.Procedures Revised
05000423/LER-1996-003-01, :on 960312,temporary I-Beams Located Overhead of Recirculation Spray Sys HXs Discovered.Caused by Inadequate Work Control.Work Control Procedures Revised
05000413/LER-1996-003-06, :on 960802,TS 3.0.3 Required Shutdown Initiated,Due to Ventilation Sys Motor Failures.Unit 2 Was Shutdown to MOD 5 Per Requirements of TS 3.0.3.Damaged Motors Were Replaced
05000325/LER-1996-007-01, :on 960509,high Pressure Coolant Injection Declared Inoperable.Caused by Degradation of Valve Stem Packing.Valve 1-E41-F001 Repaired & Valve Packing Replaced
05000293/LER-1996-005, :on 960419,automatic Scram Occurred Due to Turbine Vibration During Planned Power Reduction.Turbine Vibration Trip Setting That Initiates Trip of Turbine Due to High Vibration Changed
05000293/LER-1996-002, :on 960205,loss of Valve Position Indication for MO-1301-16 Occurred.Caused by Loose Control Power Fuse in Breaker B1864.Investigation & Troubleshooting Plan Was Implemented
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
05000382/LER-1996-009-01, :on 960725,failure of Containment Vacuum Relief Valves CVR-402A & CVR-402B Occurred.Caused by Excessive Roughness in Valve Body Bore.Valves Replaced & Retested
05000445/LER-1996-005, :on 960310,entry Into TS 3.0.3 Occurred Due to Cracked Weld in SI Sys Piping.Removed & Replaced Cracked Weldment W/New Weld
05000445/LER-1996-006, :on 960411,rod Control Malfunction Resulted in Manual Rt.Replaced Bank Overlap Counter Circuit Board
05000327/LER-1996-009-01, :on 960718,auxiliary Building Secondary Containment Boundary/Fire Barrier Not Maintained as Required by Design.Caused by Failure to Follow Design Control Process
05000382/LER-1992-011, :on 920924,noted That CCW Sys Grab Sample Per TS Action Requirement Had Not Been Taken within Specified Periodicity,Due to Personnel Error.Processing of Permits Will Be Assigned Only to Plant Technicians
05000528/LER-1985-015, :on 850312,Tech Spec Surveillance Requirement Not Completed within Required Interval.Caused by Personnel Error Involving Scheduling of Surveillance Test Procedure. Effective Scheduling Coordination Implemented
05000382/LER-1996-012-01, :on 951111,normally Locked Closed Valve Discovered 1.5 Turns Open.Caused by Equipment Failure. Closed & Repaired CS-118A to Ensure Ease of Operation.W/
05000382/LER-1996-013-01, :on 960822,possible Operation in Excess of 100% Licensed Power.Cause Is Being Investigated
05000334/LER-1996-011, :on 960820,failed to Provide Administrative Control of Isolation Valves Required by Ts.Caused by Station Operating Procedures for Plant Startup Not Emphasizing TS Requirements for Valves.Revised Surveillance
05000348/LER-1996-003, :on 960602,actuation of ESF Equipment Occurred Due to Relay Contact Failure.Relay Replaced
05000382/LER-1996-007-01, :on 960411,discovered That Design Basis Flow Rates Could Not Be Achieved on Auxiliary Component Cooling Water Sys.Caused by Inadequate Design.Modified Sys Design & Reviewed Other safety-related Fluid Systems
05000413/LER-1996-004-01, :on 960506,standby Shutdown Sys Found Outside Design Basis.Caused by Misinterpretation of Info.Changed Design Basis Document Based on Corrected Calculations & Implemented Mod to Ensure Water Availability
05000424/LER-1996-004-01, :on 960420,surveillance Test Not Performed for Neutron Flux Channel.Caused by Personnel Error.Operations Personnel Counseled,Event Reviewed in Training & Procedures Will Be Modified
05000317/LER-1996-002, :on 960410,required Fire Watch Missed.Caused by Lack of Fire Watch Ownership.Circumstances of Event Will Be Reviewed W/Appropriate Groups
05000334/LER-1996-005, :on 960401,core Alterations Performed Without Required Radiation Monitors Being in Svc Occurred.Caused by Contradiction Between Refueling Procedure & Reactor Vessel Head Removal.Procedures Revised
05000369/LER-1985-004-01, :on 850128,reactor Tripped on lo-lo Steam Generator Level When Main Feedwater Pump Tripped on Low Suction Pressure Signal.Caused by Failure of Pneumatic Pressure Transmitter.Components Replaced
05000445/LER-1996-004-01, :on 960326,potential Failure of Personnel Airlock Control Sys for Units Was Discovered.Caused by Failure to Consider All Design & Licensing Interfaces in Design Validation.Completed Procedure Changes
05000334/LER-1996-001-01, :on 960320,main Steam Valve Setpoints Not within Specification.Caused by Relatively Small Amount of Normal Setpoint Drift.C/A:Main Steam Safety Valve Adjustment Performed
05000293/LER-1995-011, :on 951206,RCICS Was Inoperable Due to Unplanned Maint to Replace Intermittent Tripping Power Inverter.Mr 19503503 Was Initiated to Perform Initial Troubleshooting
05000374/LER-1996-001-01, :on 960117,discovered During TS Hourly Fire Watch Surveillance of Div I,Ii & III CSC Pump Rooms,Div I Room Not Observed.Caused by Personnel Error.Fire Watch Surveillance for Div I Room Established
05000338/LER-1996-002, :on 960303,containment Particulate & Gaseous Radiation Monitors Inoperable.Caused by Inadequate Review of Containment Gaseous & Particulate Radiation Monitor. Suppl & Exhaust MOVs Shut
05000280/LER-1984-024, :on 841116,spurious Safety Injection Occurred When Returning Consequences Limiting Safeguards,High Phase (Equivalent to Containment Depressurization Actuation Sys) to Svc.Impact on Unit Minimal
05000336/LER-1996-006-01, :on 960207,service Water Pump Motor Flood Protection Not Provided.Caused by Inadequate Administrative Controls.Administrative Controls Established
05000261/LER-1984-003-01, :on 840521,two Steam Generator Snubbers Being Tested Offsite Were Low on Fluid.Rear Monoball Bearing on One Steam Generator Snubber Failed at Less than Design Load. All Snubbers Rebuilt
05000354/LER-1996-001, :on 960113,safety & Turbine Acs Heat Exchangers Fouled W/Detritus Occurred Due to Failed Svc Water Strainer. Strainers Replaced & Enhanced Maint & Design Mod
05000354/LER-1995-016, :on 950708-09,SDC Bypass Event Occurred, Rendering SDC Mode of RHR Sys Inoperable Due to Procedural non-compliance & Inadequate Operator Knowledge,Skills & Training.Special Training on Event Conducted
05000414/LER-1996-001-02, :on 960206,loss of Offsite Power Due to Electrical Component Failures Occurred.Caused by Application of Type of Resistor Bushing Used.All Resister Bushing in Application Replaced
05000285/LER-1995-007, :on 951108,potential Tripping of 480 Volt Circuit Breakers W/Digital Reip Units Identified.Caused by Circuit Breaker Component Not Operating as Specified.Issued SA for Operability
05000369/LER-1996-002-01, :on 960204,inadvertent Manual Initiation of Unit 1 FW Isolation Occurred Due to Inappropriate Action. OPS Mgt Evaluated Depressing & Holding Train a & B CF Isolation
05000382/LER-1996-003-01, :on 960130,logarithmic Power Channels Indicated 5 Percent of Scale Below Actual Power.Caused by Not Periodically cross-correlating Log Power to Linear Power. Recalibrated Log Power Channels
05000370/LER-1984-027, :on 841025,manual Reactor Trip Initiated Following Loss of Main Feedwater Pump 2A Due to Water in Pump Control Oil Sys.Water Drained from Filters & Sys Restarted
05000445/LER-1996-002-01, :on 960122,loss of MFW Flow Due to FW Isolation Valves Closing Resulted in Manual Rt.Caused by Less than Adequate Initial Troubleshooting Plan.Revised Operations Procedures
05000327/LER-1996-001-02, :on 960121,discovered Fire Watch Patrol Did Not Patrol Some Assigned Areas in Control Bldg & on 960126,fire Watch Patrol Not Performed within Timeframe Required by Ts. Appropriate Disciplinary Action Taken
05000370/LER-1985-004-02, :on 850204,small Hole Discovered in Metal Plate Covering Fire Barrier Penetration in Floor of Control Room. Cause Unknown.Fire Watch Established,Pending Repair of Hole
05000395/LER-1996-002, :on 960126,voluntary Entry Into TS 3.0.3 Made to Recover Train a Chillwater Due to Equipment Problem on Chiller a Which Was Supplying Train a ESF Equipment.No Specific Corrective Action for Event Warranted
05000446/LER-1996-002, :on 960126,noted That TS Surveillance for Turbine Overspeed Missed Due to Oversight in Rescheduling Required Surveillance by Cognizant Personnel.Test Completed on 960126 & Event Reviewed as Lesson Learned
05000423/LER-1995-019-02, :on 951201,leaks Found in 3/4 Inch Socket Welds on C RCS Loop Flow Instrumentation Line & RCP Seal Injection Drain Line.Caused by Vibration Induced Fatigue at Stress Riser in Weld.Welds & Weld Bosses Removed
05000305/LER-1985-003, :on 850208,reactor Tripped.Caused by Decrease in Steam Generator Vol to Low Level Alarm Setpoints. Corrective Action Being Investigated
05000354/LER-1996-001-03, :on 960113,safety & Turbine Acs HXs Fouled W/Grass Due to Failed Service Water Strainer.Caused by Detritus Overloading.Strainer Replaced & Maint & Design Mods Enhanced
05000269/LER-1995-007, :on 951106,LPIS Was Technically Inoperable Due to Deficient Design Change.Valves Modified to Prevent Key from Vibrating Out of Keyway
05000271/LER-1992-005, :on 920306,Group 1 Primary Containment Isolation & Plant Scram Occurred.Caused by Failure of Contacts on Reactor Mode Switch to Fully Close.Switch Taken to Refuel & Scram & Isolation Reset
05000423/LER-1995-021-02, :on 951207,loop Stop Valves on One Loop Opened W/O Performing TS Surveillance Due to Procedure Inadequacy. Util Evaluated Whether Change Needed to Clarify TS
05000382/LER-1995-007-04, :on 950525,ECW Sys Flow Degradation Occurred Due to Iron Deposits Settling on Seats of Individual Room Cooler Chilled Water Manual Throttle Valves.Restored Chilled Water Flow to Established Design Conditions
05000382/LER-1995-006-04, :on 951207,failed to Provide Backup Overcurrent Protection Due to Personnel Error.Installed Backup Overcurrent Protection for Circuits & Tested Two Breakers
05000302/LER-1995-027, :on 951206,leak Found in Underground EFW Pump Recirculation Line.Caused by Nearby Excavation Using Power Tools.Mechanical Clamping Device Temporarily Used to Stop Leak Until Repairs Scheduled for 960229
05000298/LER-1995-017, :on 951023,safety/relief & Safety Valves Found Outside TS Limiting Safety Sys Setting.Caused by Corrosion Bonding of Pilot Disc to Pilot Seat.Safety Relief Valve Surveillance Procedure Revised
05000364/LER-1995-008, :on 951128,reactor Trip Occurred During DEH Card Change Out.Caused by Latent Design Defect in DEH Circuitry.Three Cards W/Latest Hardware Rev Replaced Correcting Defect
05000325/LER-1992-011, :on 920406,coil of Control Relay in Containment Atmospheric Control Sys Failed,Resulting in Loss of Power to Containment Isolation Valves.Caused by Relay Aging.Relay Coil Replaced & Action Plan Developed
05000354/LER-1995-030, :on 951106,FRVS Noble Gas Surveillance Was Missed Due to Personnel Error.Revised Procedure
05000302/LER-1995-024, :on 951030,annubar Flow Tap Orientation Caused Seismic Qualification Concerns Resulted in Operation Outside Design Basis of Plant.Caused by Personnel Error.Placed Aft Under Administrative Control
05000331/LER-1995-011, :on 951019,during Surveillance Test Procedure, a Sdg Outboard Bearing Temp Reached 205 F.Caused by Incorrectly Installed Room Temp Controller.Controller Reconfigured
05000354/LER-1995-029, :on 951102,both Trains of Standby Liquid Control Declared Inoperable Due to Failure to Perform Surveillance Per IST Requirements.Audit Team Performed in- Depth Review of Sys
05000354/LER-1995-020, :on 950908,automatic Actuation of HPCI Suction Path Swapover ESF Occurred.Caused by Absence of Realistic Operating Band Considering Loop Inaccuracies.Incorporated Realistic Band Into Operations Procedures
05000301/LER-1995-004-01, :on 951026,inadvertent ESF Actuation Occurred as Result of Improper Relay Alignment.Assigned Addl Technician to Concurrently Check Proper Removal & Installation of Remaining Relays
05000354/LER-1995-028, :on 951030,failed to Exert Best Efforts to Restore Liquid Effluent Radiation Monitoring Sys to Operable Status.Caused by Low Mgt Priority Given.Improved Related Processes
05000382/LER-1995-005-04, :on 951102,calibr Input Data for Rosemount Instrument Transmitters Was in Error.Caused by Ineffective Review Process for Instrument Calculations.Established Administrative Control for SIT Level Control
05000301/LER-1995-005-01, :on 951025,plugged 46 Tubes Due to Degradation in Roll Transition,Tubesheet Crevice & Tube Support Plate Regions.Performed Closeout Insps Following Maint of Each Sg
05000285/LER-1995-006, :on 950824,improper Start of Number 1 DG Caused Rt.Caused by Inadequate Administrative Controls on Critical Parameter.Provided Addl Administrative Controls to Ensure That Governor Was Operated Correctly
05000327/LER-1995-015, :on 951101,ESF Actuation Occurred Due to Misinterpretation of Procedural Note of Determining Differential Proessure Across MSIV Prior to Opening Valve. Counseled Involved Personnel
05000424/LER-1995-006-01, :on 951101,maximum Reactor Power Exceeded Over 8 Hour Period Due to Oversight in Original Validation of Computer Calorimetric Software in Identifying Limitations of Software Program.Changed Procedures
05000327/LER-1995-013, :on 951010,surveillance Was Missed During Mode 6.Caused by Inadequate Training of Licensed Operators in Use of 12-wk Schedule.Revised Procedures to Include Comprehensive List of Routine SIs
05000456/LER-1995-013-04, :on 951012,fire Protection App R Design Discrepancies Occurred Due to Inadequate Evaluations During Preparation of Original Analysis.Maintained Hourly Fire Watches for All Fire Zones
05000263/LER-1995-007-01, :on 951012,valve RHR 74-2 Found Closed & Unlocked.Caused by Personnel Errors.Event Discussed W/Shift Personnel & Formal Training Will Be Provided to Personnel Involved in Valve line-ups
05000354/LER-1995-024-01, :on 950928,missed Special Rept for Filtration Recirculation Ventilation Sys High Range Noble Gas Monitor Rendered Inoperable on 950913.Caused by Personnel Error. Required Special Rept 95-03 Issued on 951024
05000456/LER-1995-011-04, :on 951002,B Dilution Prevention Valve Opened W/Unit in Mode 5 & One Source Range Nuclear Instrument Channel Inoperable Due to Inadequate Surveillance Procedure. Closed & re-hanged Temp Lift on 1CV8428
05000348/LER-1995-009, :on 951008,classified Results of SG Tube Insps Performed During Unit 1 Thirteenth Refueling Outage of 328 Tubes as Category C-8 Due to 3.34% of Tubes Inspected Being Defective.Required Tubes Plugged or Repaired
05000369/LER-1995-005-03, :on 950927,manual Reactor Trip Initiated After Valve 1SM-0007AB,MSIV Steam Line a Moved to Fail Safe (Closed) Position.Cause Unknown.Associated Fuses,Sv Coils, Some Wiring Terminations & Relays Replaced
05000412/LER-1995-007-01, :on 951003,recirculation Spray Sys B Train Header Flow Was Less than TS Requirement Due to Personnel Error.Properly Adjusted 2SWS-MOV105D
05000336/LER-1995-036, :on 950922,identified That Quarterly Surveillance for Valve 2-SW-1A Missed Due to Personnel Error.Valve 2-SW-1A Tested & Verified Operable & IST Program Surveillances Reviewed
05000339/LER-1995-001-01, :on 950403,MS Pressurizer Safety Valve Setpoints Out of Tolerance Due to Setpoint Drift.Repaired MSSVs
05000315/LER-1984-007-01, :on 840522,detector Code Programming Error Discovered in Calculational Logic While Modifying Code. Procedure Change Made to Require Independent Line by Line Review of Coding
05000336/LER-1995-034, :on 950822,TS Surveillance Was Missed Due to Personnel Error.Performed Surveillance Shortly After Time Interval Had Expired
05000277/LER-1995-003-03, :on 950815,unplanned ESF Actuation Occurred When Wire Was Out in Junction Box.Evaluated Addl Labelling & Print Revs
05000293/LER-1995-008, :on 950814,primary Containment Sys Isolation Valve Was Unable to Close Fully on Automatic Signal Due to Wiring Discrepancy.Trained Personnel for Maint on Specific Event
05000317/LER-1995-004-01, :on 950816,inoperable Fire Barrier Penetration Seal Was Discovered.Caused by Inadequate Engineering Oversight & Less than Adequate Surveillance Procedure.Sealed Penetration Seal
05000336/LER-1995-033, :on 950809,manual RT Initiated Due to Loss of Atmospheric Dump Valve Control.Caused by Blown Fuse on Circuit Board in Control Circuit of Valve.Circuit Board Replaced & Valve Returned to Svc
05000416/LER-1984-028, :on 840507,during Storm,Arcing Occurred Across Open Disconnect for 500 Kv Switchyard Breaker,Causing Loss of Power Which Resulted in Reactor Water Cleanup Reactor Isolation.Plant Shut Down
05000327/LER-1992-006, :on 920209,failure to Verify RCS Flow Above TS Limits Led to LCO 3.2.5.After Exit from Lco,Failure to Check SI Criteria Renewed Error.Caused by Personnel Error.Si Data Sheets Revised & Personnel Counselled
05000287/LER-1984-002-02, :on 840216,reactor Trip Initiated by Reactor Protection Sys When High RCS Pressure Setpoint Reached. Caused by Failure of Rc Loop a Flow Transmitter Due to Malfunctioning Amplifier Assembly
05000423/LER-1995-014-01, :on 950713,TDAFWP Did Not Start within One Minute as Required by TS While Performing Surveillance Test on Tdafwp Due to Governor Valve Position.Revised Procedures
05000277/LER-1991-039, :on 911206,excessive Leakage Noted in RHR Sys B Loop Injection Check Valve &/Or Associated Bypass Valve. Caused by Obstruction in Valve Seating Area.Valve Disassembled & Repaired
05000336/LER-1995-024, :on 950614,surveillance Frequency for Fire Detection Instrumentation Was Incorrect Due to Personnel Error.Revised Applicable Surveillance Procedure That Changed Frequency to Required semi-annual Interval
05000425/LER-1995-005, :on 950627,incorrect Train Identification Resulted in Missed TS Surveillance Test.Caused by Cognitive Personnel Error on Part of Uss.Counseled Uss on Importance of Accuracy in Identifying Components
05000328/LER-1991-006-03, :on 911107,reactor Tripped on lo-lo Steam Generator Level in Loop 4 During MSIV Partial Stroke Test. Caused by Failure of Limit Switch to Actuate.Switch Replaced & MSIV Successfully Retested
05000318/LER-1995-005, :on 950524,facility Manually Tripped Due Ground Fault in Mcc.Area Around MCC 208 Quarantined,Action Taken to Strengthen Expectations & Work Practices & Maint Orders Issued to Inspect,Repair,Clean & Test MCC 208
05000364/LER-1995-005, :on 950601,loss of electro-hydraulic Fluid Resulted in Manual Rts.Repaired & Selected Welds on Eh Sys of 2A & 2B SGFP
05000369/LER-1995-001-01, :on 950129,Unit 1 Manual Reactor Trip Was Initiated Due to Equipment Failure.Replaced Type of Fuse in Applications Deemed Critical to Plant Operation
05000317/LER-1995-001-01, :on 950415,Unit 1 Entered TS 3.0.3 When EDG Supplying Backup Power Became Inoperable.Caused by Leaking Fuel Injector Pump Due to Improper Drainage.Drain Lines Cleaned
05000318/LER-1995-004, :on 950414,fire Occurred in Section of Expansion Joint Matl in K Line Wall,Burning Approx Three Linear Feet of Cork Matl.Caused by Sparks from Welding Near Wall.Fire Watches Posted & Walkdown Performed
05000336/LER-1995-016, :on 950428,operator W/Inactive SRO License Assumed Position of Fuel Handling SRO for Movement of Upper Guide Structure Into Rv.Caused by Failure to Recognize Inactive Status.Briefing Conducted
05000285/LER-1995-002, :on 950327,containment Polar Crane Was Used to Move Reactor Vessel Internals Lift Rig Over Reactor Vessel.Usar & TS Did Not Clearly Identify Containment Closure Requirements.Ca Will Revise USAR
05000336/LER-1995-014, :on 950404,continuous Fire Watch Was Found Sleeping in West 480 Volt Switchgear Room Due to Personnel Error.Posted Another Individual as Fire Watch
05000334/LER-1991-020, :on 910622,hydrogen Recombiner Declared Inoperable Due to Incorrect Thermocouple/Control Circuit Wiring.Design Change Package 1757 Implemented to Reverse Wiring of Thermocouples 3A & 4A
05000269/LER-1994-004, :on 950215,determined That LPSW Sys Inoperable in Past Due Design Deficiency.Hpsw Design Basis Document Will Be Reviewed & Updated as Required
05000302/LER-1991-004, :on 910514,reactor Vessel Level Instruments Discovered Incorrectly Calibrated.Caused by Personnel Error. Plant Recalibrated Reactor Vessel to Proper Range & Review by Engineer Performed
05000336/LER-1995-002-01, :on 950125,confirmed That Assumptions Made for Original Design Basis Analysis for Containment Sump Isolation Valve non-conservative.Caused by Inadequate Evaluation.Second Review Completed
05000263/LER-1995-001, :on 950206,missed Grab Sample on SW Radiation While Maint Was Being Performed on Sample Pump.Caused by No Administrative Aids to Ensure That Shift Took Required Samples.Took Sample Immediately
05000346/LER-1995-001, :on 950126,determined That LOCA Analysis Results for 2 Ft Core Elevation Potentially non-conservative Due to Modeling Errors.Vendor Evaluated Current Fuel Cycle to Determine If Operating Limits Valid
05000369/LER-1995-002-01, :on 950221,Train a of Control Room Ventilation Sys Judged Technically Past Inoperable Occurred.Caused by Inadequate Review of Cumulative Effects of Field Changes. Throttling Procedure Put in Place
05000369/LER-1994-007, :on 941024,DGs 1B & 2A Experienced Inadvertent Starts Due to Unanticipated Interaction of Components. Struthers Dunn 219DXBP Type Relays Used in DG Control Circuitry for Four DGs Replaced
05000412/LER-1995-002-01, :on 950313,spurious Train B Control Room Emergency Habitability Sys Actuation Generated.Caused by Unintentional Electrical Shorting Across Adjacent Terminal Screws.Air Bottle Subsystem Isolated
05000423/LER-1995-009, :on 950426, as Found Leak Rate for Containment Isolation Valves Exceeded TS Bypass Leakage Limit.Caused by Deterioration of Resilient Valve Seats.Seats Continue to Be Replaced
05000458/LER-1995-001, :on 950125,ESG Actuation Occurred During Performance of Surveillance Test Procedure.Cause Could Not Be Determined.Isolation Had Been Reset & Steam Supply Valve Opened After Event
05000336/LER-1995-001, :on 950118,crane Operated Over Spent Fuel Pool While Enclosure Bldg Ventilation Sys Inoperable.Caused by Inadequate or Insufficient Procedures.Ts 3.9.7,3.9.14 & 3.19.15 Will Be Reviewed for Clarifications
05000336/LER-1994-033, :on 941031,loss of Containment Integrity Discovered During Course of Irradiated Fuel Movement within Containment.Caused by Failed Ventilation Exhaust Damper.Fuel Movement Stopped
05000336/LER-1994-032, :on 941028,post Incident Recirculation Fan Flow Below Design Occurred.Cause Unknown.Work Scheduled to Adjust Fan Blades as Necessary to Achieve Required Air Flow Rate.W/
05000293/LER-1994-007, :on 941228,primary Containment Pressure Boundary Degraded Due to Uninstalled Instrument Plug.Caused by Personnel Error.Isolation Valves Will Be Installed on Selected Instruments
05000285/LER-1994-011, :on 941228,SR for SG Level Check Was Unsatisfied.Caused by Inadequate Review.Dept Personnel Trained on Event
05000338/LER-1994-008-02, :on 941215,inadequate Missile Protection Due to Incomplete Procurement/Design Review of Manhole Covers.Info Action Statement for AP-41,Severe Weather Conditions Was Entered at 1045 Hr on 941215
05000369/LER-1994-009, :on 941125,boron Dilution of Unit 1 VCT Occurred Due to Procedural Deficiencies Caused by Inadequate Self Checking.Procedure CP/0/A/8400/10 Placed on Administrative Hold
05000423/LER-1994-014-02, :on 941121,TDAFWP Failed to Start During Cold Start Surveillance Test.Caused by Preexisting Conditions of Tdafwp Trip Valve Linkage.Corrective Maintenance Performed on Linkage
05000338/LER-1991-001, :on 910224,discovered That Hot Leg Safety Injection Branch Flow Above Tech Spec Requirements of Less than or Equal to 650 Gpm.Caused by Errors in Flow Measurements.Throttle Valves Adjusted
05000324/LER-1994-002, :on 940117,spurious Div 1 RCIC Isolation Signal Received,Closing Inboard Steamline Isolation Valve 2-E51-F007.Cause Unknown.Steam Leak Detection Sys Will Be Replaced During Refueling Outage
05000318/LER-1994-003-01, :on 940711,commenced Reactor Shutdown for Leak from Fatigue Crack in SIT Line.Support for Line Redesigned & Installed to Reduced Levels of Vibration to Acceptable Level & Similar Lines Examined
05000269/LER-1994-003-03, :on 940623,discovered That Failure of an Air Pressure Regulator Resulted in Kh Main Transformer Lockout Relay Actuation.Caused by Design Deficiency.Repaired Affected Air System Components
05000445/LER-1991-009, :on 910321,automatic Isolation of Steam Generator Blowdown Occurred.Caused by Cognitive Personnel Error & Inadequate Procedural Guidance.Operations Shift Crew Counselled & Procedure Revised
05000285/LER-1994-004, :on 940413,fire Damper Designed to Retain Halon in Cable Spread Room in Event of Fire Was Found Improperly Latched Open.Caused by Personnel Error.Corrective Actions: Event Consequences Related to Personnel
05000259/LER-1991-002-01, :on 910201,discovered That Reactor/Turbine Bldg Ventilation Radiation Monitor 1-RM-90-250 Did Not Contain Particulate Filter & Charcoal Cartridge.Caused by Personnel Error.Filter Holder Assembly Replaced
05000336/LER-1994-018-01, :on 940602,filter Fans Crac Appeared to Be Feeding Opposite Supply Train.Caused by Incorrect Installation of Crac Sys.Plant Design Change 2 Was Implemented on 940605
05000336/LER-1994-021-01, :on 940615,determined That Shielding Had Been Installed Without Processing Temporary Shielding Request.Caused by Bricks Installed W/Inadequate Controls & Methods.Shielding Was Removed
05000317/LER-1994-005, :on 940424,experienced Partial Loss of Offsite Power.Caused by 13.8 Kv Voltage Regulator Fault.Voltage Regulator 1102 Replaced
05000285/LER-1994-005, :on 940427,found That out-of-tolerance Test Results for Snubbers Not Appropriately Addressed Due to Procedural Inadequacy.Snubber Surveillance Test Procedure Will Be Revised
05000366/LER-1994-005, :on 940423,Full RPS & Partial Group 2 PCIS Actuation Occurred.Caused by Inadvertent Action on Part of I&C Technician.Rps Signal Reset & Affected Sys Returned to Lineups Required for Plant Conditions
05000285/LER-1994-001, :on 940211,safeguards Actuation & Reactor Trip Occurred Due to Relay Failure.Containment Pressure High Signal Relay Replaced & Sent for Investigation of Failure Mechanism
05000285/LER-1993-019, :on 931209,AFW Pumps Rendered Inoperable Due to Inappropriate Testing Lineup.Surveillance Test SE-ST-AFW-3005 Will Be Revised
05000285/LER-1993-014, :on 930926,PORV PCV-102-1 Inadvertently Opened During Test.Caused by Improper Valve Maint During 1984 Mod. C/A:Pcv Refurbished & Tested
05000269/LER-1993-009-01, :on 930927,determined That Epsl Channel 1 Not Operable Per TS in Past as Result of Design & Installation Deficiencies in Load Shed Circuitry.Wiring Associated w/3TD 10 Amp Dc Fuse Block Reconfigured
05000366/LER-1994-002-01, :on 940301,during Monthly Operability Test of HPCI Thrust Bearing Temp Increased to 437 F & Decreased Below 200 F.Caused by Mfg Error in Thrust Bearing Housing. Failed Bearing & Gear Coupling Replaced
05000412/LER-1990-018, :on 901026,ESF Actuation - Inadvertent Diesel Start Occurred & Deficiency Discovered in D/G Ventilation Fan Circuit
05000423/LER-1994-005, :on 940210,containment Drain Sump Level & Pumped Captivity Monitoring Sys Not Performing in Accordance W/Ts.Caused by Personnel Error.After Design & Procedural Improvements,Original Sump/Pump Back in Svc
05000423/LER-1994-001-02, :on 940120,discovered That Overtemp Delta T & Overpower Delta T Channel Checks Not Being Adequately Performed Due to Procedural Deficiency.Channel Check on Four Delta T Channels Performed
05000416/LER-1993-010, :on 931004,loss of Shutdown Cooling & ESF Actuation Occurred During Unit Outage Due to Class 1E Bus Voltage Oscillations.Replaced Faulty Current Limiting Card
05000445/LER-1990-029, :on 900910,turbine/reactor Trip Caused by Failure of Personnel to Assure Availability of Drain Path. Operators Responded to Trip Per EOP & Stabilized Plant in Mode 3
05000445/LER-1990-033, :on 900926,personnel Error Lead to Momentary Loss of Containment Integrity
05000454/LER-1993-004-10, :on 931208,notified of Potential Inoperability of AFW Switchover Due to Inadequate Design Change.Temporary Alteration Installed to Move Feeds for 4 Seconds SW Switchover Time Delay Relay
05000445/LER-1990-023, :on 900808,reactor Tripped on Loss of Feedwater Flow.Caused by Loose Fuse in Main Feedwater Control Power Circuit.Corrective Maint Performed on Malfunctioning Fuse Clip
05000455/LER-1993-006-08, :on 930924,identified That Surveillance for Source Range Instrumentation Missed Due to Incorrect Computer Status Update.Changes Made to Update Process.W/
05000293/LER-1993-022, :on 930910,simultaneous Loss of Preferred Offsite Power & Automatic Scram Resulting from Load Rejection Occurred.Caused by Load Rejection.Switchyard Walked Down for Evidence of Damage
05000285/LER-1993-017, :on 931116,time Delay Relays for Offsite Power Low Signal (Opls) Found Out of Tolerence Due to Inadequate Technical Review of Calibr Procedures for Opls Circuitry. Opls Calibr Procedures Revised
05000213/LER-1993-016, :on 930920,determined That Potential Existed to Divert Inventory from Dwst.Issue of Thoroughness in Engineering Analyses & Evaluations Will Be Addressed by Reviewing Event W/Engineering Personnel
05000285/LER-1993-015, :on 931109,emergency Boration of RCS Was Initiated Due to Induced Electrical Noise.Performed Maint on WR Nuclear Instrumentation Channels a & D
05000285/LER-1993-016, :on 931113,CEA Withdrew from Reactor Core & Rod 31 Became Fully Withdrawn.Caused by Lack of Ground Detection Sys for Associated Power Supplies.Ground Detection for CRD Power Supply Installed
05000293/LER-1993-021, :on 930824,unplanned Automatic Actuation of RCIC Portion of PCIS Occurred Due to RCIC Turbine Steam Supply Line High Flow Signal.Personnel Will Evaluate Setpoint for RCIC Sys High Steam Flow
05000331/LER-1993-011, :on 931111,control Bldg Chiller a Tripped During Normal Operation While Chiller B Removed from Svc for Preplanned Maint.Caused by Ineffective Setup for Low Load Conditions.Chillers Rebalanced
05000317/LER-1993-006, :on 931010,surveillance on Electrical Fire Pump Missed Due to Personnel Error.Pump Declared Inoperable & Missed Surveillance Performed
05000483/LER-1990-011, :on 901003,ESF Actuations Occurred Due to Spurious Signal on Fuel Bldg Radiation Monitor
05000293/LER-1993-018, :on 930721,planned Shutdown Initiated Due to Unidentified Leakage of 3 Gpm.On 930722,planned Shutdown Became TS Required Shutdown When Insp Revealed Leakage to Be Rc Pressure Boundary Leakage.Leakage Repaired
05000285/LER-1993-004, :on 930301,confirmed That Channel D Axial Shape Index (Asi) Being Calculated in Reverse Since 921031-930301 Due to Drawing Discrepancies Associated W/Control Channel B. Temporary Mod 92-078 & Standing Order 0-25 Revised
05000318/LER-1993-003-01, :on 930625,SG Tripped Due to Low Water Level. Caused by Insufficient Feedwater Addition Due to Inadequate Communication.Reemphasis on Improved Communication Stressed
05000285/LER-1993-010, :on 930611,1 of 14 Halon Cylinders Did Not Meet Min Pressure Acceptance Criteria Listed in Semiannual Switchgear Rooms Surveillance Test.Caused by Failure of Test to Include Necessary Steps.Cylinder Recharged
05000317/LER-1993-003, :on 930610,dual Unit Trip Occurred Due to Partial Loss of Offsite Power.Flashover Protection Relay for Breaker 552-61 Replaced & Training for Personnel W/ Access to Relays Will Be Reinforced
05000302/LER-1993-006, :on 930520,inadequately Secured Separation Barrier Identified That Could Affect Control Switches for safety-related Equipment on Main Control Board.Caused by Human Error.Placard Posted to Restrict Area
05000285/LER-1993-008, :on 930520,determined That TS SR Not Satisfied for Stack Flow Indicator,Per Amend 137 Issued on 910307. Caused by Lack of Attention to Detail.Calibr & Functional Test Procedures Developed
05000293/LER-1993-010, :on 930519,SUT Became de-energized During Planned Calibr of Turbine/Generator Relays Lockout Test While Shut Down.Caused by Personnel Error.Discussion Conducted W/Personnel Re Attention to Detail
05000285/LER-1993-007, :on 930430,unplanned Emergency Generator Start & RT Signal Occurred.Caused by Inadequate Attention to Detail,Labeling of Fuse Drawers,Caution Signs & Training. Labeling & Caution Signs Upgraded
05000285/LER-1993-006, :on 930118,Halon Fire Suppression Sys for Switchgear Rooms Disabled to Allow Repair/Replacement of Halon Sys Piping.On 930427,individual Responsible for Fire Watch Not Present.Individual Relieved of Responsibilities
05000445/LER-1990-016, :on 900521,engineering Determined That Three Atmospheric Relief Valves Declared Inoperable Resulting in Entry Into Tech Spec Limiting Condition for Operation 3.0.3. Pneumatic Controls Drifted Out of Calibr
05000445/LER-1990-015, :on 900520,chemistry Sample Special Condition Surveillance Missed.Caused by Procedural Error.Procedures Revised to Provide Appropriate Cautions Re Required Sample
05000445/LER-1990-014, :on 900514,containment Penetration Improperly Isolated While Containment Isolation Valve Made Inoperable for Repairs.Caused by Inadequate Review of Work Order. Supervisor Counseled & Shift Order Issued
05000266/LER-1990-005, :on 900510,steam Generator lo-lo Level Reactor Trip Occurred During Cold Shutdown.Caused by Inadequate Warning Sign Posting.Nonconformance Rept Written to Document Event & Recommend Evaluation
05000482/LER-1990-008, :on 900504,fuel Bldg/Control Room Ventilation Isolation Signals Received from Exhaust Radiation Monitor. Caused by Burned Out Lamp & Blown Fuse in Power Supply.Fuse & Lamp Replaced & Monitor Returned to Svc
05000445/LER-1990-010, :on 900428 & 29,2-h Surveillance Interval, Including 25% Extension Allowed by Tech Spec 4.0.2,exceeded. Caused by Personnel Error.Procedure Enhancements Initiated & Personnel Involved Counseled
05000482/LER-1990-004, :on 900405,Tech Spec Surveillance Requirement Not Satisfied Because of Personnel Error in Scheduling Surveillance Test.Procedure Adm 02-300 Revised
05000424/LER-1990-010, :on 900418,oncoming Shift Supervisor Found That Containment Level C Temp Improperly Recorded.Caused by Data Being Recorded & Reviewed from Malfunctioning Indication.Individuals Counseled
05000285/LER-1993-005, :on 930422,determined That Incident Reportable in That SIRWT Recirculation Piping Associated w/MR-FC-83-046 Used Between Dec 1986 & 1992 Refueling Outage in Unacceptable Configuration
05000499/LER-1993-001, :on 930123,unit Automatically Tripped from Full Power Due to Turbine Trip Above P-9 Setpoint as Result of Depressurization of electro-hydraulic Control Supply Header. Failed Line & Differential Transformer Replaced
05000333/LER-1993-004-01, :on 930225,scram Initiated by Taking Reactor Mode Switch Out of Run Mode When Water Level Observed to Be Below Normal.Caused by Slush Ice Present in Front of Bar Racks.Water Level Indicator Installed
05000333/LER-1993-006-01, :on 930225,fire Pump 76P-2 Declared Inoperable Due to Inadequate Pump Discharge Pressure.On 930226,fire Pump 76P-1 Declared Inoperable Due to Engine Overheating. Fire Pumps Will Be Replaced/Rebuilt
05000338/LER-1993-005, :on 930219,emergency Bus de-energized Due to Emergency Bus Feeder Breakers Tripping Open.Caused by Failure of Two Degraded Voltage Auxiliary Relays.Procedures Revised to Preclude Emergency Trip
05000445/LER-1993-002, :on 930124,spurious Signal from Pressurizer Pressure Channel 2 Resulted in Overtemp Nitrogen 16 Reactor Trip.Caused by Instrument Failure During Surveillance Testing.Failed Component Replaced
05000298/LER-1990-003, :on 900328,safety/relief Valve & Safety Valve Setpoint Variance Not within Tech Spec Limits.Cause Not Determined.Valves Inspected,Refurbished & Satisfactorily Retested at Wyle Labs Before Return to Site
05000336/LER-1994-007-01, :on 940412,CRAC & Ebfs Were Inoperable Due to Previous Charcoal Testing Performed to Industry Std Different than Ts.Corrective Actions:Ts Changed to Reflect Newest Charcoal Testing Procedure
05000338/LER-1990-003, :on 900228,52 Valves Identified Not Included in Tech Spec Required Monthly Containment Integrity Verification Surveillance Program.Caused by Personnel Error & Inadequate Procedure.Procedure Revised
05000293/LER-1989-029, :on 890914,locked High Radiation Area Door Found to Have Been Unsecured Contrary to Tech Spec 6.13.2. Caused by Failure to Adhere to Approved Procedures. Training on Access Requirements Initiated
05000483/LER-2018-001, Violation of Technical Specification 3.6.3 Containment Isolation Manual Found in Open Position
05000410/LER-1998-017, :on 980602,control Room Ventilation Sys Was Declared Inoperable.Caused by Original Design Deficiency. Mod Designed,Tested & Implemented Prior to Startup from RF06 to Correct Design Deficiency
05000400/LER-1997-020, :on 970814,inadequate Fire Protection Provided for safety-related EDG Fuel Oil Transfer Pump Cables Resulted in Operation Outside Design Basis.Caused by Engineering Oversight.Established Fire Watches
05000400/LER-1997-001-01, :on 970131,automatic Reactor Tripped Resulting from SG low-low Level.Caused by Inadvertent Closure of Mfiv (1FW-159) & Faulty Hydraulic Relays.Shuttle Valves Replaced, SG Level Discrepancy Investigated
05000400/LER-1996-021, :on 961107,inadequate post-maint Testing Following Repairs on Containment Isolation Valve 1SP-208 Identified.Caused by Misinterpretation of ASME Code. Procedures Revised
05000400/LER-1987-040, :on 870630,discovered That Surveillance Interval for Calorimetric Exceeded.Caused by Personnel Error.Night Order Issued Instructing Personnel on Importance of Performing Surveillances
05000458/LER-2015-003, Regarding Operations Prohibited by Technical Specifications and Loss of Safety Function Due to Inoperability of Division 2 Containment Penetration Leakage Control System
05000269/LER-2014-001, Regarding Unanalyzed Condition Associated with the 13.8kV Emergency Power Cables Located in the Underground Trench
05000397/LER-2014-003, Regarding Degraded Tornado Missile Barrier
05000237/LER-2013-001, Secondary Containment Inoperable Due to Two Interlock Doors Being Open Simultaneously
05000237/LER-2009-004, Shutdown Cooling System Isolation During Cooldown Due to Temperature Instrumentation Failure
05000219/LER-2008-001, Automatic Reactor Shutdown Caused by Main Transformer Failure
05000390/LER-2001-004, Turbine/Reactor Initiated by an Invalid AMSAC Signal
05000425/LER-1998-004-02, :on 980419,defeat of Turbine Trip Function Led to Improper Mode Entry.Caused by Inadequate Administrative Controls of Work Process.Controls to Prevent Recurrence Are Being Instituted
05000266/LER-1998-015, :on 980420,containments Fan Cooler Test Results Were Outside Acceptance Criteria.Cause Is Still Being Evaluated.Pressure Washing of Air Side of Cooling Coils for All Four Unit 1 CFCs Has Been Completed
05000277/LER-1998-003-01, :on 980513,failure to Meet TS for Main Control Room Emergency Ventilation,Was Identified.Caused by Failure to Follow GP-25 Procedure Guidance.Main Control Room Emergency Ventilation Relays Inspected for Loose Screws
05000302/LER-1998-006, :on 980514,low Rc Pressure Bistable Contacts Were Not Uniquely Tested.Caused by Personnel Error.Revised Sps SP-110 A,B,C & D
05000348/LER-1998-003, :on 970315,failure to Comply W/Ts 4.5.3.2 & 3.5.2,was Determined.Caused by Personnel Error.Personnel Involved Have Been Coached Re Procedure Adherence
05000341/LER-1989-007, :on 890307,increasing Trend Observed in Vibration of Number 8 Bearing on Main Turbine Generator. Cause Undetermined.Turbine Balanced in Subsequent Outage. Disassembly &/Or Insp of Portions Planned
05000341/LER-1987-021, :on 870607,RCS Leakage Limit Surveillance Interval,Including 25% Max Allowable Extension,Exceeded by 1 H.Caused by Personnel Error.Instructions Given to Personnel Re Completing Surveillance on Time
05000354/LER-1987-034, :on 870730,reactor Scram Occurred Due to Inadvertent Deenergizing of 120 Volt Ac Uninterruptible Power Supply Inverter.Caused by Inadequate Equipment Operator Training Program.Training Upgraded
05000483/LER-1998-006, :on 980707,RCS Pressurizer Safety Relief Valves Failed Low on as Found Set Pressure Test.Caused by Set Pressure Drift.Pressurizer SRVs Were Refurbished Following Set Pressure Testing
05000334/LER-1997-022, :on 970730,ESFA of P-12 Interlock Occurred Due to Decreased Reactor Water Temp.Caused by Operator Unfamiliarity W/Level Controller Response in All Situations. Controller Windup Will Be Demonstrated
05000302/LER-1997-024, :on 970731,feedwater Valves Did Not Meet Requirements for Main Steam Line or Feedwater Line Break Event Mitigation.Caused by Inadequate Design & Calculation Errors.Fsar Will Be Updated by 971130
05000425/LER-1998-001-04, :on 980308,personnel Noticed Discrepancies Between Demand Position Step Counters & Digital Rod Position Indicators.Caused by Rod Control Firing Card Operating Abnormally.Firing Card Replaced
05000425/LER-1998-002-01, :on 980311,evaluation Determined That as-found lug-to-post Connection Represented Condition Outside of Design Basis,Per 10CFR50.72(b)(1)(ii)(B).Caused by Cognitive Personnel Error.Nut Placed on Terminal Post
05000293/LER-1999-006-02, :on 990705,both EDGs Were Inoperable.Caused by Ambient Air Temp Exceeding 88 Degrees Fahrenheit.Temporary Mods Tm 99-41 & Tm 99-42,implemented for EDG a Were Completed on 990706.With
05000302/LER-1997-020, :on 970718,identified Failure of CREVS in-place Testing of HEPA Filters to Meet Improved TS Surveillance Requirement.Caused by Cognitive Personnel Error.Will Revise Ventilation Filter Test Program
05000409/LER-1987-001, :on 870107,reactor Scrammed When Turbine Stop Valve Partially Closed.Possibly Caused When Turbine Reset During Simulated Overspeed Test or Oil Pressure at Stop Valve Temporarily Decreasing.Valve Closed
05000293/LER-1987-004, :on 870218,dry Chemical Fire Suppression Sys of Piping Trench Below Emergency Diesel Generator Discovered Inoperable.Caused by Personnel Error.Work Prioritization Identification Requirements Reviewed
05000334/LER-1998-029, :on 981218,inadequate Meterological Instrumentation Calibr Led to Failure to Comply with Tss.Caused by Human Error.Current Wind Direction Sensor Was Replaced.With
05000324/LER-1998-002-01, :on 980708,excessive FW Temp Reduction Was Noted as Result of Loss of Stator CW with Main Turbine. Caused by Failure to Analyze Worst Case Lfwh Transient. Process Computer Databank Was Updated.With
05000327/LER-1992-022, :on 921122,CREVS Declared Inoperable Because of Closure of Tornado Dampers.Caused by Tornado Warning & Sighting of Tornado Moving Toward Snp.Corrective Actions Not Applicable
05000416/LER-1984-052, :on 841124,scram Occurred on Low Reactor Water Level.Caused by Opening of Feedwater Isolation Valve Per Cleanup Procedure.Level Restored by Resetting Reactor Feed Pump Turbine a
05000293/LER-1995-009, :on 950821,discovered Surveillance Procedure 8.5.1.3, Core Spray Motor Operated Valve Quarterly Operability Test Not Performed.Caused by Personnel Error. Appropriate Mgt Attention/Action Taken
05000334/LER-1995-011, :on 951218,missed Source Range Surveillance Occurred.Caused by Lack of Attention to Detail by Operations Supervisors Controlling Plant Shutdown Procedure.Operations Supervisors Involved Counseled
05000336/LER-1995-043, :on 951115,reactor Core Power Exceeded Rated Thermal Power of 2,700 Mw for Period of 11 H.Caused by Personnel Error.Changed Procedure OP 2316A
05000324/LER-1991-017-02, :on 911017,Wyle Labs Notified Util That safety- Relief Valves Exceeded Tech Spec Setpoint Drift.Caused by pilot-disc-to-seat Bonding Preventing Valves from Actuating.Ts Change Will Be Requested
05000277/LER-1994-005-02, :on 940722,actual Torus Water Level Less than That Indicated on Narrow Range Instrumentation.Initial Ref Marking Used to Support Calibr Activities Not Correct