05000482/LER-1985-052, :on 850712,control Room Ventilation Isolation Signal Initiated Due to Alarm on Control Room HVAC Chlorine Monitor.Caused by Broken Filter Paper Tape.Tape Replaced
05000482/LER-1985-050, :on 850710,hi-hi Water Level in Steam Generator Initiated Feedwater Isolation,Main Turbine Trip & Feedwater Pump Trip.Caused by Excessive Leakage Through Feedwater Control Valve.Valve Connections Adjusted
05000482/LER-1985-040, :on Seven Occasions Between 850702 & 12,ESF Actuation Initiated Control Room Intake Radiation Monitor Spurious Alarm.Caused by Mismatch Between Software & Hardware in Microprocessing Unit
05000482/LER-1985-042, :on 850705 & 11,ESF Actuation Occurred Resulting in Feedwater Isolation,Main Turbine Trip & Main Feedwater Pump Trips.Caused by High Water Levels in Steam Generator & Overlap Between Setpoints
05000482/LER-1985-045, :on 850623,reactor Trip Occurred During Performance of Surveillance Test STS IC-211A.Caused by Inadvertent Breaker Trip Due to Confusing Procedural Steps. Procedure Revised
05000482/LER-1985-047, :on 850622,hourly Fire Watch Patrol Not Performed in Several Areas of Auxiliary Bldg.Caused by Personnel Error.Individual Dismissed & Hourly Fire Watch Patrols Performed by Permanent Personnel
05000482/LER-1985-048, :on 850628,daily Calorimetric Heat Balance Test & Adjustment of ex-core Nuclear Instrumentation Channel Gains Determined Not Performed from 850615-0623.Caused by Isolated Personnel Oversight
05000482/LER-1985-023, :on 850501,reactor Protection Sys Trip Signal & ESFAS Initiated During Startup Test Procedure in Mode 3. Caused by Personnel Error.Plant Testing Temporarily Suspended.Personnel Counseled
05000482/LER-1985-022, :on 850430,safety Injection & Main Steam Line Isolation Occurred,Causing ESF Actuation.Unusual Event Declared & Subsequently Canceled.Caused by Interference from Operator Radio.Radio Use Restricted
05000482/LER-1985-010, :on 850413,preaction Sprinkler Sys for Redundant Sys or Components Discovered Taken Out of Svc on 850411 W/O Establishing Continuous Fire Watch.Caused by Personnel Error.Event Reviewed W/Personnel
05000482/LER-1985-039, :on 850606,during Test of Steam Dump Control Sys,Reactor Trip & Low Coolant Sys Average Temp Initiated Feedwater Isolation Signal.Caused by lo-lo Steam Generator Water Level.Water Levels Returned to Normal
05000482/LER-1985-043, :on 850609,feedwater Isolation Signal,Main Turbine Trip & Steam Generator Feed Pump Turbine Trip Signals Occurred Due to hi-hi Water Level in Steam Generator A.Caused by Leak Through Main Control Valves
05000482/LER-1985-026, :on 850506,ESFAS Signal Initiated When Two Radiation Monitors Deenergized Due to Inadvertent Loss of Power to safety-related 480-volt Ac Load Ctr.Caused by Personnel Error.Sys Restored to Normal
05000482/LER-1985-041, :on 850609 & 13,auxiliary Feedwater Actuation & Steam Generator Blowdown & Sample Isolation Occurred. Caused by Main Feedwater Pump a Trips
05000482/LER-1985-024, :on 850501,ESFAS Signal Initiated When Steam Generator a Level Indication Spiked Low,Resulting in Initiation of Feedwater Isolation Signal & Auxiliary Feedwater Actuation Signal
05000482/LER-1985-025, :on 850501,two Main Steam Line Isolation Valves Declared Inoperable.Caused by Hydraulic Oil Pump Malfunction.Oil Pumps Replaced & Valves Tested
05000482/LER-1985-037, :on 850602,spurious Electronic Spike in Control Room Intake Radiation Monitor (GK-RE-04) Occurred. Caused by Mismatch Between Software & Hardware in Microprocessing Unit RM-80
05000482/LER-1985-021, :on 850428,ESF Actuation Occurred.Caused by Anticipatory Trip Generated by rate-sensitive Steam Generator Circuiting Due to Personnel Error.Setpoint Actuation Will Be Stressed During Training
05000482/LER-1985-019, :on 850426,auxiliary Feedwater Actuation Signal Occurred.Caused by Operator Placing Switch FC-HS-25 in Permit Position.Switch Returned to Block Position.Error Discussed W/Operating Personnel
05000482/LER-1985-017, :on 850424,Ruskin Mfg Co Fire Dampers Found in Violation of Tech Specs Since Issuance of OL on 850311. Caused by Insufficient Clearance Between Damper Frames & Penetration Sleeves.Fire Watches Established
05000482/LER-1985-038, :on 850604,auxiliary Feedwater Actuation Signal & Steam Generator Blowdown & Sample Isolation Signal Initiated.Caused by Auxiliary Boiler Trip.Pumps Secured
05000482/LER-1985-014, :on 850421,ESFAS Initiated When Control Room Chlorine Monitor Ran Out of Paper,Causing Ventilation Isolation Signal.Caused by Personnel Error.Schedule for Changing Paper Increased to Twice Weekly
05000482/LER-1985-044, :on 850614,feedwater Isolation,Auxiliary Feedwater Actuation,Steam Generator Blowdown & Sample Isolation Occurred.Caused by Higher than Actual Indication of Reactor Power Level
05000482/LER-1985-036, :on 850531,when Steam Generator Level Bistable Tripped in Error During Maint,Esfas Initiated.All ESF Equipment Responded Properly.No Equipment Damage or Release of Radioactivity Noted
05000482/LER-1985-031, :on 850611,ESF Actuation Signal Initiated Due to hi-hi Water Level in Steam Generator C,Initiating Feedwater Isolation,Main Turbine Trip & Main Feedwater Pump Trip Signals
05000482/LER-1985-036-01, :on 850531,ESF Actuation Signal Initiated When Steam Generator Level Bistable Tripped in Error During Maint Activity.Caused by Technician Pressing Trip Button on Wrong Bistable Logic Card.Personnel Counseled
05000482/LER-1985-012, :on 850419,inadvertent Train B Safety Injection Occurred.Caused by Loose Limit Switch Tug in Valve Motor Operator.Switch Lug Repaired
05000482/LER-1985-033, :on 850523,manual Control Room Ventilation Isolation Signal Initiated.Caused by Electronic Spike from Control Room Chlorine Monitor Displaying Erratic Behavior. Potential Equipment Mod Under Evaluation
05000482/LER-1985-011, :on 850412,control Room Ventilation Isolation Signal Occurred.Caused by Spurious Spike on Chlorine Monitor GK-AITS-2.Monitor Placed in Bypass & Later Returned to Svc
05000482/LER-1985-034, :on 850524,containment Water Level Instrument LF-LI-09 Found in out-of-svc Condition.Caused by Obstruction on Slide Pole Resulting from Insulation Activity.Obstruction Removed & Instrument Returned to Svc
05000482/LER-1985-028, :on 850516,auxiliary Feedwater Actuation Signal Initiated When Steam Generator D Decreased Below lo-lo Actuation Setpoint.Caused by Personnel Error.Personnel Counseled & Required to Read LER
05000482/LER-1985-030, :on 850518,ESFAS & Feedwater Isolation Occurred When Steam Generator Level Transmitter Sensed Erroneous High Level Condition.Caused by Pressure Perturbation in Common Sensing Line
05000482/LER-1985-027, :on 850506,ESF Actuation Occurred,Resulting in Safety Injection & Main Steam Line Isolation Due to Low Steam Line Pressure Signal on Steam Generator A.Caused by Personnel Error.Personnel Counseled
05000482/LER-1985-013, :on 850506,15,23,26 & 30,ESF Actuation Signal Initiated by Control Room Intake Radiation Monitor Spurious Alarm,Causing Control Room Ventilation Isolation Signal. Caused by Mismatch in Microprocessing Unit
05000482/LER-1985-020, :on 850429,ESF Actuation Signal Initiated When Steam Generator C Water Level Increased to High Level Setpoint.Caused by Personnel Error.Event Considered Isolated Case.Shift Supervisor & Personnel Counseled
05000482/LER-1985-010-01, :on 850411,preaction Sprinkler Sys for Area Containing Redundant Sys Taken Out of Svc W/O Establishing Required Continuous Fire Watch.Situation Discovered on 850413.Caused by Personnel Error
05000482/LER-1985-009, :on 850412,ESF Actuation Signal Initiated When Several Radiation Monitors Deenergized.Caused by Ground Fault Indication Tripping Power Supply Breaker.Breaker Reset & Power Restored
05000482/LER-1985-006, 00:on 850407,ESF Actuation Resulted Due to Inadvertent Actuation of Fuel Bldg Ventilation & Control Room Ventilation Isolation Signals.Caused by Personnel Error.Personnel Counseled
05000482/LER-1985-029, :on 850506,containment Purge Isolation Control Room Ventilation Isolation & Fuel Bldg Ventilation Isolation Signals Occurred During Recovery from Safety Injection. Caused by Procedural Deficiency