Semantic search
Jump to navigation
Jump to search
| Issue date | Title | Topic | |
|---|---|---|---|
| ML20046B148 | 30 July 1993 | LER 93-012-00:on 930702,reactor Core Isolation Cooling Sys Declared Inoperable Due to Associated Bus Voltage Dropping Below TS Limits.Sent Operator to Cycle Timer Which Caused Affected Contact to reclose.W/930730 Ltr | Safe Shutdown |
| ML20045D933 | 2 July 1993 | LER 93-004-00:on 930604,unexpected CRD Low Charging Water Header Scram Received Followed by Charging Water Header A2/B2 Alarm.Caused by Crud or Foreign Matl Passing Through Suction Filter.Filters Cleaned & reused.W/930702 | |
| ML20045D750 | 23 June 1993 | LER 93-003-00:on 930524,Div 1 ECCS Initiation Signal Received & LPCS Pump,Lpci Pump 2A & EDG Unit 0 Automatically Started.Caused by Personnel Error.Pumps Secured & Event Documented in Personnel file.W/930623 Ltr | |
| ML20044E416 | 28 May 1993 | LER 92-009-01:on 920923,spurious Auto Start of CR Ventilation Emergency make-up Train Occurred Due to High Radiation Spike.Radiation Monitor Circuit modified.W/930528 Ltr | |
| ML20044E419 | 21 May 1993 | LER 93-011-00:on 930423,manual Scram Initiated.Caused by Disconnected Linkage on Valve Positioner on Heater Drain Valve Due to Loose Jam Nut.Tailgate Session Will Be Held W/ Instrument Maint Dept Re Jam nuts.W/930521 Ltr | Scram Discharge Volume |
| ML20044D516 | 15 May 1993 | LER 92-007-01:on 920613,high Radiation Spike Received from CR Ventilation Process Radiation Monitor,Initiating Emergency Makeup Train B.Caused by Normal Variations in Radiation Readings.Spike modified.W/930515 Ltr | |
| ML20044D557 | 14 May 1993 | LER 93-010-00:on 930414,DG Cooling Water Pump Automatically Tripped on Magnetic Overload.Caused by Inexperienced Trainee in Operation of Control Lever.Lesson Plans & Training Programs for Operators to Be reviewed.W/930514 Ltr | |
| ML20044C980 | 7 May 1993 | LER 91-010-01:on 910719 & 0805,CR a Ventilation Emergency Makeup Fan auto-started on Spurious Trip of CR Air Intake Process Radiation Monitor.Caused by Normal Variations in Background Radiation.Supply Board replaced.W/930507 Ltr | |
| ML20044B616 | 25 February 1993 | LER 93-002-00:on 930126,Unit 1 Manual Scram Due to a SRV Being Stuck Open Due to Duct Tape Being Over Actuators Air Valve Manifold Exhaust Port.Maint Procedures That Involve Cleanliness reviewed.W/930225 Ltr | |
| ML20024G977 | 10 May 1991 | LER 91-005-00:on 910410,determined That Tech Spec Required Surveillance of Suppression Chamber Oxygen Sampling Missed. Caused by Inadequate Review of Tech Spec Change.Drywell & Suppression Chamber Checked for oxygen.W/910510 Ltr | Missed surveillance |
| ML20044A385 | 25 June 1990 | LER 90-008-00:on 900525,Tech Spec Hourly Fire Watch Missed Due to Miscommunications Between Security Personnel & Radiation Protection Personnel.Fire Watch re-established & Memo issued.W/900625 Ltr | High Radiation Area Fire Watch Hourly Fire Watch |
| ML20043F172 | 5 June 1990 | LER 90-009-00:on 900510,RWCU Outboard Suction Isolation Valve 2G33-F004 Auto Closed Which Tripped RWCU Pump B. Caused by Procedure Deficiency.Procedure LTS-500-209 Will Be revised.W/900605 Ltr | |
| ML20043F128 | 1 June 1990 | LER 90-009-00:on 900511,apparent Ruptured Diaphragm Found on Pressure Differential Switch in RCIC Steam Line.Caused by Torn Diaphragm Inside Switch.Replacement Switch Installed, Calibr & Functionally Tested satisfactorily.W/900608 Ltr | |
| ML20043B568 | 23 May 1990 | LER 89-027-01:on 891113,primary Containment Isolation Sys Group 1 Isolation Occurred During Surveillance Testing. Caused by Burnt Out Window Light Bulbs on Alarm Window. Light Bulbs Replaced & Jumpers installed.W/900523 Ltr | Reactor Vessel Water Level Half scram |
| ML20043A772 | 18 May 1990 | LER 90-007-00:on 900421,reactor Protection Sys Bus a Transfer & Reactor Recirculation Hydraulic Power Unit a Inboard Isolation Valves Closed,Causing Partial Group II isolation.Out-of-svc Procedure revised.W/900518 Ltr | |
| ML20043D059 | 18 May 1990 | LER 90-008-00:on 900502,ESF Actuation of Control Room B Emergency Ctk Ventilation Makeup Fan Occurred.Caused by Procedure deficiency.LTS-800-205 & Similar Procedures Will Be revised.W/900601 Ltr | |
| ML20042H021 | 10 May 1990 | LER 90-006-00:on 900412,loop a Primary Containment Chilled Water Sys Inboard Isolation Valves & Reactor Bldg Closed Cooling Water Sys Inboard Isolation Valve Went Closed.Caused by Inadequate Procedure.Procedures revised.W/900510 Ltr | |
| ML20042F900 | 4 May 1990 | LER 90-005-00:on 900411,experienced Loss of Dc Power to Portion of Div I Primary Containment Isolation Sys Logic Which Resulted in Isolation Signal & Actuation.Caused by Failure to Update Drawings & procedures.W/900504 Ltr | |
| ML20042F194 | 30 April 1990 | LER 89-025-01:on 891101,sys Auxiliary Transformer Feed to Bus 142Y Tripped Open When Door Containing Undervoltage Relays Closed.Caused by Misalignment of Door.Door Repaired. W/900430 Ltr | |
| ML20012D534 | 16 March 1990 | LER 90-003-01:on 900201,RCIC Isolation Signal Occurred During Warmup.Caused by Spurious High Steam Flow Signal.Rcic Sys Piping Integrity Verified & Isolation Logic Reset.W/ 900316 Ltr | |
| ML20012D537 | 16 March 1990 | LER 90-002-01:on 900129,oil in Diesel Generator Governor 1A Found to Be Low & Could Not Be Seen in Sight Glass.Caused by Slow Leak from Compensation Needle Valve Plug.Proper Amount of Oil Added & Operability Test performed.W/900316 Ltr | |
| ML20012C493 | 15 March 1990 | LER 90-004-00:on 900213,control Room B HVAC Intake Radiation Monitor Lost Power Causing auto-start of Emergency make-up Train B.Caused by Blown Fuses.Fuses Replaced.Logic Revs for Radiation Monitors Will Be installed.W/900315 Ltr | |
| ML20012B650 | 9 March 1990 | LER 90-002-00:on 900209,Operating Surveillance LOS-TG-W1 Determined to Have Exceeded Required Testing Interval,Per Tech Spec 3/4.7.10.Caused by Personnel Error.Personnel Counseled & Ref Procedures Will Be revised.W/900309 Ltr | Safe Shutdown Missed surveillance Grace period |
| ML20012B552 | 8 March 1990 | LER 90-001-00:on 900206,full Reactor Scram Occurred During Instrument Surveillance Testing.Caused by Actuation of APRM E Trip Circuitry.Shutdown Margin Revised & Caution Card Placed on Control Room Bench board.W/900308 Ltr | Shutdown Margin Half scram |
| ML20011F825 | 2 March 1990 | LER 90-003-00:on 900201,RCIC Received Div 2 Isolation on RCIC High Steam Line Flow.Caused by Spurious High Steam Flow Signal Generated When Steam/Water Mixture Admitted to RCIC Steam Line.Isolation Logic reset.W/900302 Ltr | |
| ML20011F555 | 28 February 1990 | LER 90-002-00:on 900129,after Filling Diesel Generator 1A Governor W/Oil,Generator Started & Declared Inoperable. Caused by Slow Leak Coming from Compensation Needle Valve Plug.Oil Added & Plug Washer replaced.W/900228 Ltr | |
| ML20006F595 | 21 February 1990 | LER 90-001-00:on 900122,RWCU Sys Received Div 1 Leakage Detection Ambient Temp High Isolation Signal,Causing Trips of RWCU Pumps a & C.Caused by Broken Thermocouple Input Lead.Lead Wire Reconnected & Isolation reset.W/900221 Ltr | |
| ML20011F492 | 16 February 1990 | LER 89-013-01:on 890907,Group I Isolation Received During Performance of Instrument Surveillance LIS-MS-401.Caused by Depressurization of Main Steam Line Low Pressure Switch. Surveillance Revised to Split Into Two parts.W/900216 Ltr | |
| ML20006E450 | 15 February 1990 | LER 89-010-01:on 890715 & 17,voltage Oscillations Noted on Div II Battery Charger,Resulting in Inoperability of HPCS Sys.Caused by Failure of Charger in High Voltage Shutdown Relay.Charger Energized & Relay replaced.W/900215 Ltr | |
| ML20006E445 | 14 February 1990 | LER 89-009-01:on 890619,diaphragm Leak Discovered in RCIC Steam Line High Flow Isolation Switch.Caused by 1 & 1/2-inch Tear in Diaphragm.Pressure Differential Switch Replaced & Calibr.Reported Per NRC Bulletin 86-002.W/900214 Ltr | |
| ML20006E398 | 14 February 1990 | LER 89-008-01:on 890228,reactor Vessel Low Water Level 2 Switch Found W/Setpoint in Excess of Reject Limit.Caused by Setpoint Drift.Channel Placed in Tripped Condition & All Static-O-Ring Pressure Switches to Be replaced.W/900214 Ltr | |
| ML20006E395 | 14 February 1990 | LER 89-010-01:on 890303,automatic Depressurization Sys Permissive Switch Found W/Setpoint in Excess of Reject Limit.Caused by Setpoint Drift.All Static-O-Ring Reactor Vessel Level Switches Will Be replaced.W/900214 Ltr | |
| ML19354D836 | 15 January 1990 | LER 89-018-00:on 891216,plant 250-volt Battery & RCIC Sys Declared Inoperable Due to Low Battery Electrolyte Temps. Caused by Failure of Div I Switchgear Heat Removal Sys Damper Actuators.Air Intake Dampers closed.W/900115 Ltr | |
| ML20042D392 | 4 January 1990 | LER 89-011-01:on 890826,spurious Reactor Protection Sys Actuation Occurred.Definite Cause of Trip Not Determined. Brief Disturbance in Reactor Protection Sys Allowed Some Contactors to Trip.Procedure revised.W/900104 Ltr | |
| ML20005E274 | 22 December 1989 | LER 89-028-00:on 891204,RHR Shutdown Cooling Suction Header Outboard Isolation Valve Automatically Isolated.Caused by Miscommunication Between Technician & Station Operator.Task Force Developed to Review event.W/891222 Ltr | High Radiation Area Missed surveillance |
| ML19351A630 | 15 December 1989 | LER 89-006-01:on 890214,reactor Vessel Low Water Level 3 Switch Setpoint Found Out of Tolerance.Caused by Setpoint Drift.Level Switch to Be Replaced by Analog Trip Sys During First Quarter 1990.W/891215 Ltr | Reactor Vessel Water Level |
| ML20011D134 | 14 December 1989 | LER 89-017-00:on 891117,flow Switch FS-2E22-N006 Found W/ Setpoint Out of Tolerance Above Reject Limit.Caused by Setpoint Drift.Work Request Written to Replace Flow Switch. W/891214 Ltr | |
| ML19351A675 | 12 December 1989 | LER 89-027-00:on 891113,primary Containment Isolation Sys Group I Isolation Occurred While Performing Instrument Surveillance.Caused by Loss of Power to Leak Detection Sys Logic.Isolation reset.W/891213 Ltr | Reactor Vessel Water Level |
| ML19332F008 | 8 December 1989 | LER 89-016-00:on 891109,RWCU Isolation Occurred While Instrument Surveillance on Ventilation Differential Temp Isolation Functional Test in Progress.Caused by Faulty Thermocouple.Thermocouple repaired.W/891208 Ltr | |
| ML20005D662 | 6 December 1989 | LER 89-026-00:on 891106,inadvertent Primary Containment Isolation Actuation Occurred While Clearing out-of-svc. Caused by Inadequate Logic Setup During Mod Installation. Trip Status & Output Switches repositioned.W/891206 Ltr | |
| ML19332F243 | 1 December 1989 | LER 89-025-00:on 891101,sys Auxiliary Transformer Feed to Bus 142Y Tripped Open When Equipment Operator Closed Door Containing Relays.Caused by Misalignment of Door.Isolations Reset,Bus Energized & Circuit Logic tested.W/891201 Ltr | |
| ML19332E658 | 29 November 1989 | LER 89-015-00:on 891030,shift Control Room Engineer Noted That Quarterly Standby Liquid Control Operating Surveillance LOS-SC-Q1 Was Past Critical Date.Caused by Clerical Data Entry Error.Missed Surveillance performed.W/891129 Ltr | Missed surveillance |
| ML19332D518 | 22 November 1989 | LER 89-018-01:on 890515,RCIC Received Div I & Div II Isolation on RCIC High Steam Line Flow.Caused by Spurious High Steam Flow Signal When Steam Added to RCIC Steam Line. Special Test Initiated.Isolation Logic reset.W/891122 Ltr | |
| ML19327C260 | 17 November 1989 | LER 89-014-00:on 891020,primary Containment Isolation Sys Group 4 Isolation Occurred Causing Isolation Dampers to Close.Caused by Opening of Div 2 125-volt Dc Breaker.Power Supply replaced.W/891117 Ltr | Emergency Lighting |
| ML19325F341 | 13 November 1989 | LER 89-024-00:on 891013 & 30,unsealed Openings in Main Control Room Floor & Main Control Room West Wall Discovered. Caused by Wide Gap Between Structural Beam & Cable Tray. Openings Sealed & Fire Watch established.W/891113 Ltr | Fire Barrier Fire Watch Hourly Fire Watch |
| ML19324C175 | 8 November 1989 | LER 89-012-01:on 890309,diaphragm Leak Found in Pressure Differential Switch 1E31-N013BB.Caused by Tear Found in Diaphragm.Replacement Switch Installed,Calibr & Functionally Tested satisfactorily.W/891108 Ltr | |
| ML20024E912 | 26 August 1983 | LER 83-093/03L-0:on 830801,discovered full-in Indication on Core Display for Control Rod 34-47 Inoperable.Caused by Failed Switching Transistor on Data Memory Board 19.Data Memory Board replaced.W/830826 Ltr | |
| ML20024B838 | 5 July 1983 | LER 83-060/03L-0:on 830606,following Turbine Trip & Scram Due to High Vibration on Main Turbine,Reactor Recirculation Breaker 4B Closed.Cause Undetermined.Auxiliary Contacts cleaned.W/830705 Ltr | |
| ML20024B072 | 16 June 1983 | Updated LER 83-012/03X-1:on 830210,w/reactor in Cold Shutdown,Setpoints for Switches 1E31-N612A/B Found Above Tech Spec Limits.Cause Unknown.Switches calibr.W/830616 Ltr | |
| ML20024A696 | 14 June 1983 | LER 83-051/03L-0:on 830516,reactor Protection Sys Trip Channel H2 Limit Switch Failed to Operate Properly.Cause Unknown.Limit Switch readjusted.W/830614 Ltr |