05000311/LER-1991-004-02, :on 910218,radiation Monitoring Sys intermediate-range Vent Monitor 2R45B Spiked High,Causing Channel 2R41 to Deenergize.Caused by Damaged Cable Shield Connection.Detector Cable Replaced
05000272/LER-1989-003, :on 881010,discovered That Relay Room Penetrations,Identified in Sept 1988 Special Rept,Not Addressed Per Tech Specs.Caused by Personnel Not Including Seals in Special Rept.Individuals Counseled
05000311/LER-1988-017-01, :on 880831,reactor Trip Occurred After Turbine Trip as Result of Steam Generator hi-hi Level.Caused by Design/Equipment Problem Associated w/23BF19 Valve.Maint Requirements Will Be Modified
05000373/LER-1997-028, :on 970618,missed RHR Sys Increased Frequency Surveillance Resulted in Operation to Be Outside of TS Requirements Due to Personnel Error.Improved Procedures Governing Station Surveillances
05000373/LER-1998-004-02, :on 980227,TS Fire Watch Was Missed Due to Personnel Error.Permanent Policy Was Established to Ensure That Fire Watch Supervisors Check That Each Insp Route Started at Top of Each Hour
05000373/LER-1997-032, :on 970904,failure to Comply W/Ts Action Statement Was Determined.Caused by non-conservative Maintenance Planning.Dg 1A Control Room Frequency Meter Was Replaced
05000374/LER-1999-002-06, :on 990821,automatic Scram Occurred Due to Failure of Reactor Water Level Control.Caused by Inadequate Maint on 2A Tdrep Servo Valve 2FW163AA.Repaired Servo Valve
05000318/LER-1988-002, :on 880122,reactor Tripped Due to Reduced Feedwater Flow Due to Loss of Power to Instrument Bus 2Y10. Caused by Personnel Error.Event Reviewed W/All Electricians. Mfg Electrical Prints Clarified
05000373/LER-1997-025, :on 970613,erroneous Determination of RHR Sys Pump Operability Resulted in Operation Outside of TS Requirements Due to Personnel Error.Shift Manager Was Counseled
05000309/LER-1997-003, :on 970117,leaking Fuel Pins Identified in Westinghouse Fuel.Caused by grid-pin Fretting at mid- Assembly Fuel Spacer Grids.Replaced All Installed Westinghouse Fuel Assemblies
05000373/LER-1997-002-03, :on 970203,main Control Room & Auxiliary Equipment Room Ventilation Sys Found Outside Design Basis Due to Inadequate Initial Design.Will Perform Analysis to Determine Whether Sys Was Capable of Function
05000352/LER-1984-035, :on 841216,prior to Initial Criticality, Spurious Isolation of Reactor Water Cleanup Sys Occurred. Caused by Steam Leak Detection Sys Temp Switch Trip. Isolation Reset
05000443/LER-1995-006, :on 951030,unit Operated Above Maximum Thermal Power Level.Caused by Inadequate Procedure That Did Not Ensure That re-normalization Was Considered After Transmitter Recalibration.Revised Procedures
05000282/LER-1995-010, :on 950804,discovered Deficiencies in Flow Testing of RHR Sys.Caused by Deficient Procedure Which Failed to Consider Effect of Recirculation Line Downstream of Flow Orifice.Procedure Changes Will Be Made
05000325/LER-1991-010, :on 910415,ESF Actuation,Primary Containment Isolation Sys Group 1 Isolation Occurred.Caused by Normally Closed Contacts of Relay Failing to Maintain Closure After Relay Coil Deenergized.Relay Card Replaced
05000325/LER-1991-019, :on 910723,maint Surveillance Test Procedures Found to Be Revised Incorrectly.Caused by Lack of Formal Process for Ensuring That Procedure Was Electronically Altered Via Word Processing.Procedure Revised
05000456/LER-1995-002-07, :on 950222,insp Revealed That Line Ended W/Open Elbow Directed Into Floor Drain in Unit 1 AF Tunnel.Caused by pre-service Deficiency.Required Check Valves Installed in Unit 1 Drain Line from Unit 1 AF Tunnel
05000364/LER-1994-002-01, :on 941214,surveillance Not Performed on Swp Lube & Cooling Valves Due to Cognitive Personnel Error. Surveillance Schedules Reviewed to Ensure Corrected Schedules Placed
05000440/LER-1994-016, :on 940609,keepfill Pressure for ESW Loops B & C Was Reported as Out of Specification Low.Caused by Deficiency in SW System Design Change.Design Change Is Being Developed
05000266/LER-1993-009, :on 931202,EDG G02 Declared Inoperable Due to Relay Malfunction in One of Redundant Starting Circuits. Testing & Insp of STLO-2 Relay Ongoing to Improve Understanding of Root Cause of Failure
05000445/LER-1990-022, :on 900807,realized That Pressurizer Heatup Limit Exceeded Due to Failure to Comply W/Tech Spec Action Statement Following 900726 & 30 Events.Caused by Inadequate post-trip Review.Procedures & Training Revised
05000306/LER-1993-003-02, :on 930719,both Trains of Ventilation Safeguards Electrical Equipment Secured for Hours Due to Inadequate Administrative Control.Review of DGs D5/D6 Design Repts Will Be Performed
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
05000346/LER-1980-077-03, /03L-0:on 801013,nine of 20 Control Room Normal Ventilation Dampers Did Not Close within 10-s Limit.Caused by Insufficient Bleedoff Capacity for Control Air Header Which Feeds & Bleeds 10 Dampers Per Header
05000281/LER-1990-002-01, :on 900205,two Control Rods of Control Bank D Differed from Rod Group Demand Counter by Greater than 12 Steps.Caused by Inadequate Procedures.Rampdown Stopped & Individual Rod Position Indicators Adjusted
05000281/LER-1988-022-01, :on 880910,reactor Trip by Turbine Trip Occurred While Attempting to Maintain Turbine at Synchronous Speed.Caused by Inadequate Procedure & Faulty Valve Position Indication.Testing to Be Performed
05000281/LER-1988-011-02, :on 880423,control Room/Relay Room Chiller Removed from Svc After Second Chiller Removed from Svc. Caused by Fouled Chiller Refrigerant filter-dryer Elements. Filter-dryer Elements Replaced
05000280/LER-1987-010, :on 870313,improper Routing of App B Related Cables Discovered.Caused by Relocation of Cables Through Cable Vault & Tunnel.Fire Watch of Area at Least Once Per Shift Established & Design Changes Reviewed
05000272/LER-1991-002-02, :on 910117,RHR Pump 11 Room Cooler Leakage Noted on Metal Weld of Inlet Control Valve.On 910124,leakage Noted on SI Pump Room Cooler & Auxiliary Feedwater Pump Cooler.Caused by Equipment Failure
05000311/LER-1990-033, :on 900809,isolation Signals Received from Containment purge/pressure-vacuum Relief Sys & on 900824, Second ESF Signal Occurred.Caused by Design/Equipment. Channel 2R11A Repaired
05000272/LER-1989-026, :on 890618,controlled Shutdown Per Tech Spec 3.3.2.1 Occurred Due to Inoperable Sec.Caused by Equipment Failure.Failed Pc Boards Replaced & Sequence Timing Switch Reset
05000272/LER-1988-017-02, :on 880919,Steam Flow Channels I & II for 12 & 14 Steam Generators Declared Inoperable.Channels Were Reading -5% Low.Investigation of Root Cause Continuing.Steam Flow Channels Recalibr
05000311/LER-1988-018-01, :on 880914,discovered That Plant Vent Tritium Grab Samples Not Taken Between 880913-15.Refueling Canal Flooded on 880913 in Support of Refueling Efforts.Caused by Inadequate Administrative Controls
05000272/LER-1988-011-02, :on 880517,monthly Tech Spec Surveillance 4.0.5 for Apr Not Performed for Valve 12SW39.Caused by Personnel Error.Programmatic Review Conducted to Determine Progammatic Improvements Needed
05000311/LER-1988-010-02, :on 880509,identified That for 37 Electrical Circuits Penetrating Containment,Backup Overcurrent Protection Device Would Not Operate.Caused by Inadequate Design Review.Detailed Calculation Prepared
05000400/LER-1988-028, :on 881014,plant Tripped Due to Loss of Feedwater Caused by Low Condenser Hot Well Level.Caused by Low Level in Condenser Hot Well.Failed Relay Coil Replaced
05000397/LER-1989-015, :on 890512,three-quarter-inch High Point Vent Line Failed During Performance of HPCS Sys Operability Procedure.Caused by Reverse Bending Fatigue Caused by Vibration.Design Change Implemented
05000389/LER-1994-001-02, :on 940217,pressurizer Auxiliary Spray Declared Out of Svc.Caused by Mispositioned Valve Due to Personnel Error.Valve Correctly Realigned,Plant Records Reviewed & Nonlicensed Operators Counseled
05000335/LER-1991-002, :on 910219,unplanned Actuation of AFW Sys Occurred.Caused by Personnel Error.Engineering Revises Vendor Technical Manual to Clarify Fuse Designations & Provide Separation on Circuit Schematic
05000389/LER-1990-001-01, :on 900114,steam Generator Feed Pump 2B Low Suction Pressure Alarm Received,Condensate Pump 2A Would Not Start & Pump B Tripped on Low Suction Pressure.Caused by Personnel Error.Pump Governor Oil Drained