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Issue date | Title | Topic | |
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ML20046C313 | 28 July 1993 | LER 93-015-00:on 930630,HPCI Sys Declared Inoperable Due to Indicated Flow During Surveillance.Caused by Foreign Matl That Plugged Portion of Restricting Orifice.Restricting Orifice Removed,Cleaned & reinstalled.W/930728 Ltr | |
ML20046B524 | 26 July 1993 | LER 93-007-01:on 930317,automatic Closing of RCIC Sys Turbine Steam Supply Isolation Valves Occurred Due to High Steam Flow Signal.Increased Frequency of Valve Testing from Monthly to weekly.W/930726 Ltr | |
ML20045F860 | 30 June 1993 | LER 93-014-00:on 930531,automatic Scram Occurred,Resulting from Operation of Auxiliary Transformer Differential Relay During Power Ascension.Uat Phase B & C Differential Relays Left Interchanged as Investigative aid.W/930630 Ltr | Abnormal operational transient |
ML20045E230 | 25 June 1993 | LER 93-013-00:on 930530,RCIC Sys Declared Inoperable & 7 Day TS 3.5.D.2 LCO Entered Due to Speed Oscillations Which Occurred After Several Minutes of steady-state Operation. Caused by Actuator Failure.Actuator replaced.W/930625 Ltr | |
ML20045E225 | 25 June 1993 | LER 93-012-00:on 930529,unplanned PCIS Group I Isolation Signal Occurred While Opening MSIV During Startup,Resulting in Automatic Closing of Related Valves.Caused by Licensed Operator Error.Group 1 Isolation reset.W/930625 Ltr | |
ML20045D694 | 23 June 1993 | LER 93-011-00:on 930525,determined That Initial as-found Popping Pressures of Pilot Valves for Three Target Rock Main Steam Relief Valves Out of TS Tolerance.Caused by Setpoint Drift.Valves Reworked & Reassembled by Target Rock Corp | |
ML20045D186 | 18 June 1993 | LER 93-010-00: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.W/930618 Ltr | Safe Shutdown Abnormal operational transient |
ML20044H044 | 2 June 1993 | LER 93-009-00:on 930504,circuit Breaker Did Not Close During Planned Bus Transfer Due to Loose Control Circuit Wire.Lug Replaced & Reterminated on 930505 & Post Work Testing Completed W/Satisfactory results.W/930602 Ltr | |
ML20024G745 | 24 April 1991 | LER 91-005-00:on 910325,diesel Generator Inoperable,Causing Loss of Ac Power to Train B Components of Safety Sys & Actuating Portions of Primary/Secondary Containment Sys. Caused by Voltage Regulator failure.W/910424 Ltr | Abnormal operational transient |
ML20029A672 | 25 February 1991 | LER 91-001-00:on 910125,automatic Primary Containment Isolation Control Sys Group 5 Actuation Occurred,Resulting in Closing of RCIC Turbine Steam Supply Isolation Valves. Caused by High Flow conditions.W/910225 Ltr | |
ML20028G973 | 20 September 1990 | LER 89-036-01:on 891122,determined That HPCI Sys Inoperable Due to Inoperable Gland Seal Condenser Blower Motor.Caused by age-related Wear of Motor.Blower Motor Replaced & Blower Tested W/Satisfactory results.W/900920 Ltr | |
ML20028G912 | 18 September 1990 | LER 89-037-01:on 891130,primary Containment/Traversing in-core Probe Ball Valve Discovered to Be Almost Full Open. Caused by Damage to Valve Stem Due to Manual Manipulation of Stem.Ball Valve & Solenoid Actuator replaced.W/900918 Ltr | Squib Local Leak Rate Testing |
ML20043G354 | 12 June 1990 | LER 90-008-00:on 900513,automatic Scram Resulting from Load Rejection Occurred While at Full Power,Resulting in Trip of Generator Field Breakers.Caused by Fault on Offsite 345 Kv Transmission sys.Loss-of-field Relay replaced.W/900612 Ltr | High winds Temporary Modification |
ML20043F829 | 6 June 1990 | LER 90-007-00:on 900507,discovered That Drywell to Suppression Chamber Vacuum Breaker Surveillance Not Performed Prior to Startup in 1988.Caused by Misunderstanding of requirements.W/900606 Ltr | Excess Flow Check Valve |
ML20042F591 | 30 April 1990 | LER 90-006-00:on 900330,determined That Position of Primary Containment Sys Isolation Valve Not Recorded Daily,Per Tech Specs.Review Performed to Determine If Other Problems Existed.Plant Shut Down & Review performed.W/900430 Ltr | Hot Short Safe Shutdown Time of Discovery Condition Adverse to Quality Fuel cladding |
ML20012F575 | 6 April 1990 | LER 90-003-00:on 900311,automatic Actuation of Main Steam Sys Group 1 Portion of Primary Containment Isolation Control Sys Occurred.Caused by False High Reactor Vessel Water Level Signal.Procedure Developed Re backfill.W/900406 Ltr | Reactor Vessel Water Level |
ML20012E983 | 30 March 1990 | LER 90-002-00:on 900228,determined That Max Fraction of Limiting Power Density Not Checked Daily During Reactor Power Operation,Per Tech Spec 4.1.B.On 900323,addl Tech Spec Issue Discovered.Tech Specs changed.W/900330 Ltr | Time of Discovery |
ML20012C487 | 12 March 1990 | LER 90-001-00:on 900209,24 H Limiting Condition for Operation Entered When Two RCS Instrumentation Excess Flow Check Valves Inappropriately Verified Operable During Testing.Cause Undetermined.Two Valves replaced.W/900312 Ltr | |
ML20005G098 | 8 January 1990 | LER 89-038-00:on 891208,unplanned Automatic Reactor Protection Sys Scram Signal & Reactor Scram Occurred.Caused by False Low Reactor Vessel Water Level Signal.Local Level Indicators Satisfactorily calibr.W/900108 Ltr | Reactor Vessel Water Level Scram Discharge Volume |
ML20005F848 | 8 January 1990 | LER 89-039-00:on 891209,automatic Actuation of RHR Sys Portion of Primary Containment Isolation Control Sys Occurred.Caused by Hydrodynamic Transient That Actuated Protective High Pressure switches.W/900108 Ltr | Hydrostatic |
ML20005E855 | 30 December 1989 | LER 89-037-00:on 891130,discovered That Traversing in-core Probe Ball Valve,Mfg by Consolidated Controls,Inc,Closed,In Violation of Tech Specs.Caused by Damage to Valve Stem.Ball Valve & Actuator replaced.W/891230 Ltr | Squib |
ML20011D136 | 11 December 1989 | LER 89-035-00:on 891111,inadvertent Actuation of Portion of Secondary Containment Sys During Surveillance Testing Occurred.Caused by Location of Radiation Isolation Control Sys Channel a Logic Relay.Procedure revised.W/891211 Ltr | |
ML20005D742 | 6 December 1989 | LER 89-033-00:on 891106,automatic Actuation of Group 1 Portion of Primary Containment Isolation Control Sys (PCIS) Occurred.Caused by High Reactor Vessel Water Level.Manual Valve Closed & PCIS Logic Circuitry reset.W/891206 Ltr | Reactor Vessel Water Level |
ML19351A458 | 6 December 1989 | LER 89-034-00:on 891108,determined That Reactor Pressure Exceeded 150 Psig on 891107 W/O Performing Surveillance Procedure 8.5.4.4, HPCI Valve Operability Test. Caused by Personnel Error.Procedure initiated.W/891206 Ltr | Time of Discovery Missed surveillance |
ML19332D142 | 22 November 1989 | LER 89-031-00:on 891024,closing Times for Two in-series Primary Containment Isolation Valves Exceeded Acceptance Criteria During Shutdown Testing.Cause Undetermined.Closing Time Retested W/Satisfactory results.W/891122 Ltr | Pressure boundary leak |
ML19332D623 | 20 November 1989 | LER 89-032-00:on 891020,pneumatic Pressure Drop for Two of Four Automatic Depressurization Sys Accumulators Discovered Greater than Max Acceptable Value.Caused by Leakage from Seat of Supply Check Valves.Seat replaced.W/891120 Ltr | Mission time Pressure Boundary Leakage |
ML19324C318 | 9 November 1989 | LER 88-002-01:on 880117,full Reactor Protection Sys Scram Trip Signal Occurred During Surveillance Test,Resulting in Incomplete Actuations.Caused by Procedure Inadequacy.Logic Relay Replaced & Procedure revised.W/891109 Ltr | |
ML19324B113 | 21 October 1989 | LER 89-030-00:on 890926,control Room High Efficiency Air Filtration Sys Flowrate non-conservative Due to Procedure Error.Caused by Transcription Error.Procedure Revised & Test Reperformed Using Corrected procedure.W/891021 Ltr | |
ML19325D468 | 16 October 1989 | LER 89-029-00: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.W/891016 Ltr | High Radiation Area Locked High Radiation Area |
ML19325D186 | 10 October 1989 | LER 89-028-00:on 890907,HPCI Sys Declared Inoperable Because Mechanical Overspeed Trip Occurred During Surveillance Test. Caused by Failure of Ramp Generator Signal Converter Module. Module Removed & Sent to Mfg for exam.W/891010 Ltr | |
ML17277B822 | 20 July 1984 | LER 82-049/01X-1:on 821102,main Steam Line Safety Valve a Set W/Nitrogen at Steam Relief Setting.Caused by Personnel Error.Valve Removed & Replaced W/Properly Set Spare Valve. Procedure revised.W/840720 Ltr | |
ML20024C323 | 24 June 1983 | Updated LER 82-038/03X-1:on 820817,RCIC Steam Line High Differential Pressure Alarm Received.Caused by Air in Sensing Lines to Pressure Switches.Cross Threaded Cap Found on in-line Snubber.Snubber replaced.W/830624 Ltr | |
ML20024C221 | 24 June 1983 | Updated LER 80-053/03X-1:on 800814,0907 & 14,HPCI Turbine Exhaust Line Snubber 23-3-36 Determined Inoperable.Caused by Transient Hydrodynamic Shock During Startup & Shutdown. Snubbers upgraded.W/830624 Ltr | |
ML20024B845 | 24 June 1983 | LER 83-031/03L-0:on 830528,HPCI Sys Made Inoperable to Repair Steam Leak on AO 2301-31.Caused by Leaking Stem Packing.Packing Replaced.Valve Tested Satisfactorily.Sys Returned to svc.W/830624 Ltr | |
ML20024B832 | 24 June 1983 | LER 83-030/03L-0:on 830527,both HPCI Area Smoke Detection Sys Alarmed in Main Control Room.Caused by Valve A02301-31 Steam Leak Causing False Indications.Valve repaired.W/830624 Ltr | |
ML20024C310 | 21 June 1983 | Updated LER 79-007/03X-1:on 790212,while Performing Test 8.7.4.3,valves AO-5033A,CV-5065-10,15,16 & 17 Failed to Give Proper Position Indication When Cycled & to Close within Specified Tolerance.Cause Not stated.W/830621 Ltr | |
ML20024A886 | 16 June 1983 | LER 83-027/03L-0:on 830518,during Routine Insp,Folding Fire Door Found Inoperable.Caused by Operating Cable Becoming Detached from Pulley Due to Slack.Cable Reattached & Operating Mechanism adjusted.W/830616 Ltr | |
ML20023D169 | 9 May 1983 | Updated LER 82-008/01X-1:on 820331,HPCI Injection Valve MO-2301-8 Failed to Open in Required Manner.Caused by Missing Wire Jumper Intended to Bypass Motor Operator Torque Switch.Jumper Installed & Valve Tested Satisfactorily | |
ML20023D067 | 9 May 1983 | LER 83-021/03L-0:on 830411,during Surveillance Test 8.7.4.3, Primary Containment Isolation Valve AO-5033B Failed to Meet 10-s Closing Time Requirements.Caused by Lubricant Infiltrating Solenoid Valve Components.Components Replaced | |
ML20023D018 | 4 May 1983 | LER 83-022/03L-0:on 830413,overload on Valve Motor 1301-17 Resulted in Loss of High Pressure Core Cooling Backup Capability.Caused by Oxidation in Motor End Bell & Motor Brushes,Due to Humidity Caused by Leaking Valve Packing | |
ML20028G159 | 28 January 1983 | LER 83-002/01T-0:on 830116,flow Ref off-normal Alarm Received.Average Power Range Monitor Flux Scram Trip Settings Affected.Cause Under Investigation.Flow Inputs Monitored & Amplifier B Recalibr | |
ML20028F412 | 17 January 1983 | LER 83-002/01X-0:on 830116,while Clearing off-normal Alarm for Flow Comparators,Average Power Range Monitor Flux Scram Trip Settings Found in Nonconservative Direction.Caused by Drifting Proportional Amplifiers.Settings Checked Daily | |
ML20028B042 | 16 November 1982 | LER 82-049/01T-0:on 821102,main Steam Line Safety Valve a Set W/Nitrogen at Steam Relief Setting of 1240 Psig, Exceeding Tech Specs.Caused by Personnel Error.Set Valve Removed,Procedure Adherence Stressed & Procedure Revised | |
ML20027C980 | 20 October 1982 | LER 82-039/03L-0:on 820920,timing Tests of Three Reactor Water Cleanup Isolation Valves 1201-2,-5 & -80 Not Completed within Allowed Time.Caused by Operational Constraints Requiring Testing at Reduced Power | |
ML20027C994 | 20 October 1982 | LER 82-040/03L-0:on 820920,found Reactor Protection Sys Initiation Function of Turbine Stop Valve Completed 1 Day Late.Caused by Decision to Defer Test Due to MSIV D Line Isolation.Tracking Sys Implemented to Prevent Recurrences | |
ML20052B914 | 23 April 1982 | LER 82-010/03L-0:on 820326,during Review of Testing Requirements,Surveillance Test 8.I.4 Standby Liquid Control Sys Found Not Verified.Caused by Breakdown in Multidiscipline Review of Results | |
ML20052F207 | 14 April 1982 | Updated LER 81-060/03X-1:on 811020,determined Potential Exists to Reduce Number of Operable APRM & IRM Instrument Channels in Rod Block Trip Sys to Below Tech Spec Min | |
ML20050A632 | 19 March 1982 | Updated LER 82-055/01T-1:on 810926,during Shutdown,Yarway Level Indicators Started Oscillating.Drywell Temp Was 240 F at 81-ft W/Elevation Coolant Temp 220 F.Caused by Ineffective Drywell Cooling.Ventilation Returned to Svc | |
ML20050A452 | 19 March 1982 | LER 82-006/01T-0:on 820304,while Performing Maint Re SIL 352 on Pressure Adjustment Mechanism HPCI Stop Valve,Three Broken cap-screws Found.No Cause Determined.Screws Examined, Replaced & Sys Returned to Svc | |
ML20050A433 | 19 March 1982 | Updated LER 81-062/01X-1:on 811116,Wyle Labs Informed Util That Two Target Rock Safety Relief Valves Had Not Passed Setpoint Tests.Caused by Setpoint Shift Due to Changes to Designed Differential Forces from Excessive Pilot Leakage |