Pages that link to "10 CFR 50.73(a)(2)(iv), System Actuation"

The following pages link to 10 CFR 50.73(a)(2)(iv), System Actuation:

Displaying 50 items.

• 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release (← links)
• 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor (← links)
• 10 CFR 20.2201(a)(1)(i) (← links)
• 10 CFR 73.71(b)(1), Safeguards Event (← links)
• 10 CFR 35.3045(a)(3) (← links)
• 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation (← links)
• 10 CFR 35.3045(a)(1) (← links)
• 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat (← links)
• 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident (← links)
• 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition (← links)
• 10 CFR 50.72(a)(1)(i), Emergency Class Declaration (← links)
• 10 CFR 50.72(b)(3)(iv)(A), System Actuation (← links)
• 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown (← links)
• 10 CFR 30.50(b)(2) (← links)
• 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness (← links)
• 10 CFR 20.2201(a)(1)(ii) (← links)
• 10 CFR 50.73(a)(1), Submit an LER (← links)
• 10 CFR 20.2202(b)(1) (← links)
• 10 CFR 40.35(f) (← links)
• 10 CFR 50.72(b)(3)(xii), Transport of a Contaminated Person Offsite (← links)
• 10 CFR 30.50(b)(1) (← links)
• 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge (← links)
• 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded (← links)
• 10 CFR 20.1906(d)(2) (← links)
• 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material (← links)
• 10 CFR 76.120(c)(2) (← links)
• 10 CFR 40.60(b)(2) (← links)
• 10 CFR 40.60(b)(3) (← links)
• 10 CFR 26.719, FFD Reporting requirements (← links)
• 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect (← links)
• Agreement State (← links)
• NUREG-1022, Event Reporting Guidelines for 10 CFR 50.72 and 10 CFR 50.73 (← links)
• 05000286/LER-2015-001, Safety System Functional Failure Due to Inoperable Refueling Water Storage Tank Level Alarms Due to Freezing of the Level Instrument Sensing Lines Caused by a Failed Strip Heater (← links)
• 10 CFR 50.73(a)(2)(iv)(A), System Actuation (← links)
• 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition (← links)
• 10 CFR 50.72(b)(3)(v), Loss of Safety Function (← links)
• 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor (← links)
• 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat (← links)
• 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material (← links)
• 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident (← links)
• 10 CFR 50.73(a)(2)(v), Loss of Safety Function (← links)
• 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability (← links)
• Licensee Event Report (← links)
• 05000458/LER-2015-002, Operations Prohibited by Technical Specifications Due to Deficient Local Leak Rate Test Procedures Containing Erroneous Valve Alignments (← links)
• 10 CFR 50.73(a)(2)(iv) (redirect page) (← links)
  • 10 CFR 50.73(a)(1), Submit an LER (← links)
  • 05000458/LER-2015-002, Operations Prohibited by Technical Specifications Due to Deficient Local Leak Rate Test Procedures Containing Erroneous Valve Alignments (← links)
  • 05000529/LER-2000-007 (← links)
  • 05000529/LER-2000-001 (← links)
  • 05000482/LER-2002-003 (← links)
  • 05000336/LER-2002-002 (← links)
  • 05000287/LER-2002-001 (← links)
  • 05000530/LER-2001-001 (← links)
  • 05000458/LER-2001-001 (← links)
  • 05000457/LER-2001-002 (← links)
  • 05000457/LER-2001-001 (← links)
  • 05000455/LER-2001-002 (← links)
  • 05000440/LER-2001-003 (← links)
  • 05000440/LER-2001-001 (← links)
  • 05000413/LER-2001-001 (← links)
  • 05000412/LER-2001-001 (← links)
  • 05000373/LER-2001-001 (← links)
  • 05000366/LER-2001-001 (← links)
  • 05000336/LER-2001-004 (← links)
  • 05000336/LER-2001-003 (← links)
  • 05000335/LER-2001-007 (← links)
  • 05000334/LER-2001-003 (← links)
  • 05000334/LER-2001-002 (← links)
  • 05000334/LER-2001-001 (← links)
  • 05000325/LER-2005-006 (← links)
  • 05000313/LER-2001-001 (← links)
  • 05000293/LER-2001-005 (← links)
  • 05000277/LER-2001-004 (← links)
  • 05000277/LER-2001-001 (← links)
  • 05000275/LER-2001-002 (← links)
  • 05000272/LER-2001-008 (← links)
  • 05000269/LER-2001-002 (← links)
  • 05000247/LER-2001-001 (← links)
  • 05000458/LER-2017-008 (← links)
  • 05000301/LER-1989-010, Forwards LER 89-010-00 Describing Generation of Containment High Pressure Signal During Leak Testing of Containment Penetrations for Facility (← links)
  • 05000446/LER-1993-008, Revised Ltr Correcting Docket Number & Rept Date to LER 93-008-00 Re Auto Start of Both Motor Driven Feedwater Pumps Which Caused ESF Actuation (← links)
  • 05000285/LER-1991-009, Corrected Ltr Forwarding LER 91-009-00.Memo Stationery Inadvertently Used Instead of Letterhead Stationery for Cover Ltr (← links)
  • 05000387/LER-1984-047, Forwards LER 84-047-00,originally Issued on 841130.LER Reissued Due to Apparent Distribution Problems (← links)
  • 05000361/LER-1985-005, Forwards LER 85-005-00 Re Control Room Isolation Actuation. Events Involve Components Common to Units 2 & 3.Single Rept Submitted in Accordance w/NUREG-1022 (← links)
  • 05000254/LER-1996-003, Forwards LER 96-003-00 Re Unit 1 Start of Egd Due to Inadequate Procedure (← links)
  • 05000483/LER-1984-056, Forwards LER 84-056-00 (← links)
  • 05000265/LER-1995-006, Forwards LER 95-006-00 Re Feed Breaker for Motor Control at Switchgear Tripped from Current Overload (← links)
  • 05000311/LER-1984-010, Corrected LER 84-010-00:on 840423,during Startup Operations, Turbine Trip & Reactor Trip Occurred.Caused by hi-hi Level in Steam Generator 23.Feedwater Flow Nozzle Replaced & All Sys Performed as Designed (← links)
  • 05000498/LER-1992-007, Errata to LER 92-007-00:on 920710,correcting Typo on Page 3 of 920807 Initial Submittal,Revising Cause of Vent to Cause of Event (← links)
  • 05000029/LER-1985-010, Forwards LER 85-010-00 Re Inadvertent Reactor Scram During Maint Activity (← links)
  • 05000295/LER-1997-007, Forwards LER 97-007-00 Re Automatic Actuation of Esf. Submitted Table Identifies Actions Committed to by Util (← links)
  • 05000029/LER-1985-009, Forwards LER 85-009-00 (← links)
  • 05000265/LER-1997-001, Forwards LER 97-001-00 Re Automatic Actuation of Any Esf. Commitments Made by Ltr,Listed (← links)
  • 05000354/LER-1996-025, Forwards LER 96-025-00.Commitments Listed Including Work Order Initiated to Install Recording Instrumentation to Determine Actual Line Dynamics During Next RCIC warm-up (← links)
  • 05000327/LER-1997-007, Forwards LER 97-007-00,providing Details Re Start of Three Available Diesel Generators Occurring as Result of Cable That Was Cut While Drilling Hole in Control Room Electrical Panel (← links)
  • 05000370/LER-1997-001, Forwards LER 97-001-00 Concerning DG Load Sequencer Inadvertent Esfa (← links)
  • 05000354/LER-1997-008, Forwards LER 97-008-00 Entitled, ESF Actuation: C Svc Water Pump Auto-Start. Commitments,Encl (← links)
  • 05000260/LER-1997-001, Forwards LER 97-001-00,providing Details Concerning Reactor Scram from 100 Percent Power Resulting from Personnel Error During Surveillance Testing (← links)
  • 05000245/LER-1997-015, Forwards LER 97-015-00,documenting Event at Plant on 970321 & Licensee Commitments (← links)
  • 05000245/LER-1997-002, Forwards LER 97-002-00 Which Documents an Event That Occurred at Mnps,Unit 1 on 970114,per 10CFR50.73(a)(2)(iv). Commitments Made,Listed (← links)
  • 05000353/LER-1996-009, Forwards LER 96-009-00,documenting Event That Occurred at Limerick Generating Station,Unit 2 on 961224.LER Is Being Submitted Pursuant to Requirements of 10CFR50.73(a)(2)(iv) (← links)
  • 05000254/LER-1996-017, Forwards LER 96-017-00,for Quad Cities Nuclear Power Station.Review Plan Will Be Prepared to Identify Open Items (← links)
  • 05000296/LER-1985-014, Corrected Ltr Forwarding LER 85-014-00 Re Containment Isolation Initiation (← links)
  • 05000461/LER-1992-010, Re-isssed LER 92-010-00:on 921122,turbine Driven RFP B Min Flow Valve Failed Open Due to Broken Instrument Air Supply Line.Copper Tubing Air Supply Line Replaced W/Flexible Stainless Steel Hoses (← links)
  • 05000456/LER-1998-003, Forwards LER 98-003-00 from Braidwood Generating Station,Iaw 10CFR50.73(a)(2)(iv).Listed Commitments Made in LER (← links)
  • 05000395/LER-1988-006, Special Rept Spr 88-05:on 880512,safety Injection/Reactor Trip Occurred When MSIV a Shut During Testing.Details Described in Encl LER 88-06.Accumulative Usage Factor for Affected Safety Injection Nozzle Did Not Exceed 0.70 (← links)
  • 05000373/LER-1998-013, Forwards LER 98-013-00,IAW 10CFR50.73(a)(2)(iv).Commitments Made by Util,Encl (← links)
  • 05000245/LER-1997-023, Forwards LER 97-023-00 Per 10CFR50.73(a)(2)(iv).Commitments Made by Util,Submitted (← links)
  • 05000254/LER-1988-001, Sanitized Version of LER 88-001-00:on 880114,records Review Found Two Apparent Overexposures of Contractor Personnel During Fourth Quarter 1980.Caused by Inaccurate Secondary &/ or Primary Dosimetry.Dosimetry Sys Upgraded (← links)
  • 05000354/LER-1999-006, Forwards LER 99-006-00 Re Esfa B Channel Primary Containment Isolation Signal Actuation.Attachment a Lists Commitments Util Making to NRC Re LER (← links)
  • 05000457/LER-1998-003, Forwards LER 98-003-00 Re Unit 2 Reactor Trip.Actions & Associated Action Tracking Number That Braidwood Station Is Committed to Implement in Response to LER Described Below (← links)
  • 05000333/LER-1997-011, Forwards LER 97-011-00 Re Invalid ESF Actuation & Failure to Perform TS Required Acltions While Performing Troubleshooting Activities (← links)
  • 05000443/LER-1998-014, Forwards LER 98-014-00 for Event That Occurred at Seabrook Station on 981222.Encl 2 Is List of Util Commitments Made in Response to LER (← links)
  • 05000457/LER-1997-004, Forwards LER 97-004-00 from Braidwood Generating Station IAW Requirement of 10CFR50.73(a)(2)(iv),which Requires 30-day Rept.Ler Was Originally Transmitted W/Error in Reportability Requirements of Cover Ltr Only (← links)
  • 05000304/LER-1997-009, Forwards LER 97-009-00,re Event Which Occurred at Zion Nuclear Power Station,Unit 2.Commitments Made within Ltr Also Encl (← links)
  • 05000278/LER-1999-001, Forwards LER 99-001-00 Re 990312 ESF Actuation of Rcics Due to High Steam Flow Signal During Sys Restoration.Rept Submitted Per 10CFR50.73(a)(2)(iv) (← links)
  • 05000321/LER-1997-008, Forwards LER 97-008-00,re Personnel Error & Inadequate Procedure Which Resulted in Group 1 Isolation on Low Condenser Vacuum (← links)
  • 05000366/LER-1997-010, Forwards LER 97-010-00,re Manual Reactor Shutdown Which Resulted in Water Level Decrease & Group 2 & 5 PCIS Actuations (← links)
  • 05000457/LER-1999-002, Forwards LER 99-002-00,IAW 10CFR50.73(a)(2)(iv).Commitments Made by Util Are Listed (← links)
  • 05000353/LER-1999-002, Forwards LER 99-002-00,automatic Actuations of Primary Containment & Reactor Vessel Isolation Control Sys & Other Common Plant ESF Due to Loss of Power to a Rps/Ups Power Distribution Panel on 990419 (← links)
  • 05000327/LER-1999-001, Forwards LER 99-001-00 Re Condition That Resulted in Granting of Enforcement Discretion,Per Failure of Centrifugal Charging Pump.Condition Being Reported IAW 10CFR50.73(a)(2)(i)(B) & (a)(2)(iv) (← links)
  • 05000364/LER-1999-001, Forwards LER 99-001-00 Re Reactor Trip Due to Loss of Condenser Vacuum Steam Dump Drain Line Failure.Commitments Made by Licensee,Listed (← links)
  • 05000346/LER-1987-001, Errata to LER 87-001-00,correcting Incomplete Sentence on Page 2 (← links)
  • 05000029/LER-1986-004, Forwards LER 86-004-00 Re Reactor Scram Due to Loss of Heater Drain Pumps During Severe Lightning Storm (← links)
  • 05000000/LER-1986-018, Forwards LER 86-018-00 (← links)
  • 05000454/LER-1998-005, Forwards Revised LER 98-005-00 Which Corrects Errors Involving Incorrect LER Number on Pages 2 Through 5.No New Commitments Made within Submittal (← links)
  • 05000327/LER-1998-001, Forwards LER 98-001-00 Re Unit 1 Reactor Trip Resulting from Breaker Failure.Rept Submitted IAW 10CFR50.73(a)(2)(iv) as Event or Condition,Resulted in Automatic Actuation of Esfs, Including Reactor Protection Sys (← links)
  • 05000295/LER-1989-008, Forwards LER 89-008-00 Re Room Cooler Svc Water Supply Discrepancy Discovered on 890609 (← links)
  • 05000321/LER-1998-002, Forwards LER 98-002-00,re Blown Fuse Which Resulted in Unplanned Actuations of Engineered Safety Features IAW 10CFR50.73(a)(2)(iv) Requirements (← links)
  • 05000265/LER-1998-003, Forwards LER 98-003-00,submitted IAW 10CFR50.73(a)(2)(iv). Commitments Made within Ltr Listed (← links)
  • 05000353/LER-1998-004, Forwards LER 98-004-00,reporting Manual Actions Taken in Response to Plant Conditions,To Perform Secondary Containment Isolation,Sgts Initiation & RERS Initiation (← links)
  • 05000354/LER-1997-018, Forwards LER 97-018-00,discussing Esfa Which Resulted from RPS MG Set Breaker Trip.List of Commitments,Encl (← links)
  • 05000327/LER-1999-002, Forwards LER 99-002-00 Re Start of Units 1 & 2 EDGs as Result of Cable Being Damaged During Installation of Thermo- Lag for Kaowool Upgrade Project (← links)
  • 05000277/LER-1997-006, Forwards LER-97-006-00,concerning Unplanned ESF Actuation During 4-kV Electrical Bus Relay Testing Activities on 970923 (← links)
  • 05000304/LER-1998-001, Forwards LER 98-001-00,per 10CFR50.73(a)(2)(iv) Which Requires 30 Written Rept Following Event That Resulted in Manual or Automatic Actuation of Any Esf,Including Rps. Commitments Also Encl (← links)
  • 05000373/LER-1999-003, Forwards LER 99-003-00 IAW 10CFR50.73(a)(2)(iv).Commitments for Submittal Also Encl (← links)
  • 05000374/LER-1999-002, Forwards LER 99-002-00,IAW 10CFR50.73(a)(2)(iv).Commitments Made by Util Are Encl (← links)
  • 05000446/LER-1998-002, Forwards LER 98-002-00,re Automatic Reactor Trip Caused Subsequent to Turbine Trip Due to Loss of Turbine Plant Cooling Water. Communication Contains No New Licensing Basis Commitments Re Cpses,Units 1 & 2 (← links)
  • 05000336/LER-1997-027, Forwards LER 97-027-00,documenting Event That Occurred at Unit 2 on 970802.Commitment,listed (← links)
  • 05000416/LER-1987-006, Corrected LER 87-006-00:on 870501,isolation Valve in Steam Supply Piping to RCIC Sys Turbine Inadvertently Isolated. Caused by Personnel Error.Personnel Counseled (← links)
  • 05000382/LER-1999-011, Forwards LER 99-011-00,providing Details of Reactor Shutdown Due to Loss of Controlled bleed-off Flow.All Commitments Contained in Submittal Identified on Attached Commitment Identification/Voluntary Enhancement Form (← links)
  • 05000304/LER-1997-001, Forwards LER 97-001-00 Per 10CFR50.73(a)(2)(iv) Which Requires Written Rept Using NRC Form 366, License Event Rept, within 90 Days of Discovery of Event.Attachment a Contains Commitments Associated W/Ltr (← links)
  • 05000336/LER-1997-026, Forwards LER 97-026-00,documenting Event That Occurred at Facility on 970729.Commitments Made within Ltr,Listed (← links)
  • 05000370/LER-1999-004, Forwards LER 99-004-00,re Reactor Trip During Ssps Testing. Planned Corrective Actions in PIP Constitute Regulatory Commitments (← links)
  • 05000353/LER-1999-005, Forwards LER 99-005-00,re Actuation of Primary Containment & Reactor Vessel Isolation Control Sys,Esf.Fuse Failed Due to Mechanical Failure of Cold Solder Joint (← links)
  • 05000370/LER-1999-003, Forwards LER 99-003-00,re Inadvertent Actuation of Unit 2 Tdafwp.Supplement to Rept Is Planned to Be Submitted by 990916 (← links)
  • 05000368/LER-1986-000, Forwards Corrected LER 86-00-00 Re Inadvertent Reactor Protection Sys Actuation During Surveillance Testing.Ltr Should Be Disregarded (← links)
  • 05000368/LER-1985-022, Corrects Forwarding LER 85-022-00.Unit,docket & License Number Incorrectly Listed on Cover Ltr 2CAN118503 (← links)
  • 05000374/LER-1991-010, Corrects Forwarding LER 91-010-00.Ltr Contained Error in Rept Number Citing 1990 Instead of 1991 Event (← links)
  • 05000315/LER-1999-027, LER 315/99-027-00, Underrated Fuses Used in 250 Vdc System Could Result in Lack of Protective Coordination (← links)
  • 05000328/LER-2024-001, Reactor Trip Due to an Electrical Trouble Turbine Trip (← links)
  • 05000327/LER-2024-001, Reactor Trip Due to a Turbine Trip (← links)
  • 05000382/LER-2024-001, Manual Reactor Trip Due to Engineered Safety Features Actuation System Relay Failure (← links)
  • 05000443/LER-2023-002, Automatic Actuation of Emergency Service Water During Testing Due to a Defective Relay (← links)
  • 05000348/LER-2022-001, Outdated Relay Settings Resulted in an Automatic Reactor Trip After a Floor Tile Was Dropped in High Voltage Switch House (← links)
  • 05000327/LER-2021-001, Sequoya Nuclear Plant, Unit 1, Reactor Trip on High Neutron Flux Rate Due to Dropped Control Rods (← links)
  • 05000400/LER-2020-002, Re Manual Reactor Trip Due to Control Rod Drop During Surveillance Testing (← links)
  • 05000306/LER-1998-003-02, :on 980526,discovered Inadequate App R Fire Barriers & Unsealed Fire Barrier Penetrations.Caused by Lack of Adequate Separation of Safe Shutdown Equipment.Firewatch Has Been Established as Compensatory Measure (← links)
  • 05000354/LER-1998-004-03, :on 980522,EDG B Declared Inoperable.Caused by Contamination W/Lubrication Oil in Delivered Fuel Oil. EDG Drained,Cleaned,Refilled & Sampled (← links)
  • 05000423/LER-1998-031, :on 980519,incomplete Testing of P-4 Interlock Function Was Noted.Caused by Human Error & Inadequate Procedure Development.Revised Procedure, Ssps Refueling Tests (← links)
  • 05000271/LER-1998-015, :on 980523,invalid ESF Actuation Including SBGTS Start,Containment Vent & Purge Isolation & Rbvi Was Noted.Caused by Failed Contactor Coil.Coil Was Replaced & Sys Was Returned to Normal (← links)
  • 05000368/LER-1998-002-04, :on 980520,EFAS Automatically Actuated to Maintain Water Level in a Sg.Caused by Inadequate self- Checking of Plant Response by Control Room Operations Personnel.Operations Personnel Counseled (← links)
  • 05000285/LER-1998-005, :on 980520,161 Kv Transmission Line Circuit Breakers Tripped.Caused by Inappropriate Actuation of Deluge Sys for Transformer T1A-3.Transformer T1A-3 Was Checked to Ensure No Damage to Transformer Occurred (← links)
  • 05000277/LER-1997-009, :on 971109,reactor Scram Occurred.Caused by Generator Lockout Condition & Subsequent Turbine Trip Failure of 2A Reactor Feedpump Turbine to Trip on Demand During Recovery Activities.Reset Appropriate Scram Logics (← links)
  • 05000277/LER-1997-009-01, Forwards LER 97-009-01,reporting Reactor Scram on 971109, Resulting from Generator Lockout Condition & Subsequent Turbine Trip.Rev to Original Submittal & Discussion Anomalies Found w/2A Reactor Feedpump Turbine Trip Sys (← links)
  • 05000423/LER-1998-030, :on 980515,noted That Channel Calibr of Hydrogen Recombiners Did Not Meet Requirements of SR 4.6.4.2.b.Caused by Deficient Initial or Subsequent Reviews. Modified Hydrogen Recombiner Channel Calibr Procedures (← links)
  • 05000302/LER-1997-042, :on 970730,inadequate Engineering Evaluation Resulted in Loss of Diverse RCS Leak Detection Capability. Caused by Personnel Error.Installed New RM-A6 Particulate Radioactivity Monitor (← links)
  • 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 (← links)
  • 05000213/LER-1998-004, :on 980507,discovered Design Deficiency in Stack Radiation Monitor RMS-14B Isokinetic Sampling.Caused by Failure to Account for Spent Fuel Bldg Ventilation Flow. Will Develop CAP for RMS-14B (← links)
  • 05000213/LER-1998-006, :on 980507,design Deficiency Was Found in Stack RM RMS-14B Sampling Lines.Caused by Design Not Meeting ANSI N13.1-1969 Stds.Corrective Action Plan for RMS-14B Is Being Developed (← links)
  • 05000352/LER-1998-003, :on 980213,ESF Actuation Due to Incidental Contact W/Rv Instrument Rack Occurred.Caused by Personnel Error.Counseled Individual Involved & Training for Site Personnel (← links)
  • 05000440/LER-1998-001, :on 980506,instruction Rev Results in Inadequate Testing & Missed TS Sr.Caused by Human Error.On 980506,testing of PRM RM High Alarm Relay Contacts Was Performed (← links)
  • 05000318/LER-1998-003-01, :on 980507,relays out-of-calibration Were Noted Due to Bumped Dial & Actions Not Taken.Caused by Improperly Installed Cover.Technicians Will Be Trained on Event & Protective Covers Will Be Clearly Marked (← links)
  • 05000213/LER-1998-003, :on 980505,compensatory Sampling Frequency Exceeded Time Limit W/Sw Effluent RM Inoperable.Caused by Personnel Error.Individual Was Counseled & Technicians Were Reminded of Sampling within Required Frequency (← links)
  • 05000425/LER-1998-003-03, :on 980508,lightning Strike Leads to Turbine Reactor Trip.Caused by Main Generator Trip.Spare step-up Transformer Was Placed Into Service & Unit Was Returned to Power on 980514 (← links)
  • 05000423/LER-1997-063, :on 971231,inadequate Operator Response Time for Inadvertent SI Event Was Noted.Caused by Conflicting Program Requirements.Porvs & Associated Downstream Piping Have Been Qualified for Water Relief (← links)
  • 05000455/LER-1989-003-06, :on 890304,undervoltage Condition Occurred When Line Bus Tie Breakers Opened Due to Fault in Line. Monitors Returned to Normal Operations After Voltage Transient Passed & Breakers Reclosed (← links)
  • 05000498/LER-1998-004, :on 980430,entry Into TS 3.0.3 for Inoperable Fuel Handling Bldg Exhaust Ventilation Sys Occurred.Caused by Inadequate Plant Design Which Does Not Support Motor Repairs in AOT W/O Shutting Down Plant.Performed Maint (← links)
  • 05000295/LER-1989-004-05, :on 890308,all Rod Position Indicators Dropped to Reading of Approx 220 Steps Due to Line Voltage Regulator Failure.All Indicator Channels Declared Inoperable & Operators Prepared to Ramp Unit Down (← links)
  • 05000322/LER-1989-002, :on 890309,full Reactor Protection Sys (RPS) Actuation Occurred While Attempting to Restore Power to RPS Bus B,Causing Reactor Trip.Caused by Personnel Error While Troubleshooting.Trip Setpoints Adjusted (← links)
  • 05000220/LER-1998-011-01, :on 980503,inadvertent Actuation of RPS Circuitry Occurred Due to Personnel Error.Fuse Was Replaced & SDC Was Placed Into Svc (← links)
  • 05000313/LER-1998-002-03, :on 980505,automatic Actuation of CREVS Occurred Due to Higher than Normal Radiation at Detector When Filtration/Vacuum Assembly Was Moved in Adjacent Area. Revised Procedures to Add Noted Precautions (← links)
  • 05000313/LER-1989-008, :on 890122,determined That When Bypass Valve GCH-29 Normally Open,Ability of Radiation Monitors to Perform Required Functions Not Ensured.Caused by Error in Design Change in Bypass Line & Valve (← links)
  • 05000458/LER-1989-032, :on 890907,unplanned ESF Actuation Occurred During Surveillance Test Procedure STP-207-4536.Caused by Technician Failure to Properly Lift Lead.Trip Signal Reset, Sys Restored & Procedure Completed (← links)
  • 05000304/LER-1989-009-06, :on 890903,vent Stack Sping Flow Monitor 2LP084 Failed,Rendering Auxiliary Bldg Stack Radiation Monitor Inoperable.Caused by Personnel Error.Required Surveillance Performed (← links)
  • 05000339/LER-1989-008-01, :on 890806,ESF Valve 2-RS-MOV-201B Closed Inadvertently During Initial Performance of 2-PT-36.5.3A. Caused by Misidentification of Interlock for 2-RS-MOV-201B. Tech Spec 3.0.3 Entered & Deviation Rept Done (← links)
  • 05000456/LER-1989-008-09, :on 890905,Sargent & Lundy Engineers Evaluation Determined That W/Uncorrected Setpoints,Allowable Tech Spec Value Would Have Been Exceeded.Caused by Unclear Design Documents.Analysis of Setpoints Performed (← links)
  • 05000260/LER-1989-008, :on 890309,ESF Actuation Occurred Due to Electrical Fault on Unit Station Svc Transformer 2B.Caused by Personnel Not Taking Appropriate Actions.Power Supplies Realigned & Isolation & Actuations Reset (← links)
  • 05000369/LER-1989-023, :on 890831,ESF Actuation Occurred When Nuclear Svc Water to Auxiliary Feedwater Isolation Valve Repositioned to Open.Caused by Improperly Following Correct Procedure.Signal to Valve 1CA-86 Cleared (← links)
  • 05000346/LER-1989-003, On 890118,reactor Trip from 100% Power Occurred Due to Spurious CRD Trip Confirm Signal.Cause of Signal Narrowed to at Least One of Three Logic Boards in CRD Sys Logic Cabinet 1.Boards to Be Returned (← links)
  • 05000374/LER-1989-013-03, :on 890907,group I Isolation Was Received During Performance of Instrument Surveillance LIS-MS-401. Caused by Failure of Procedure to Provide Steps for Resetting Isolation Signal.Signal Reset (← links)
  • 05000373/LER-1989-023-01, :on 890908,reactor Recirculation Process Sample Inboard Isolation Stop Valve Spuriously Went Closed W/No Apparent Isolation Signal Present.Caused by Short in Coil of Relay 1B21H-K72.Work Request Written (← links)
  • 05000219/LER-1998-009, :on 980501,fire Program Requiring Testing Was Missed.Caused by Inadequately Transferring Test Requirements Into Procedures.B HVAC Sys Was Returned to Service on 980502 W/Fire Watch Posted as Required (← links)
  • 05000293/LER-1989-027, :on 890905,unplanned Actuation of Portion of RHR Sys/Lpci Loop Circuitry Resulted in Automatic Start of Diesel Generator a & Closed Pump Discharge Valve.Caused by Technician Error.Procedure Re Jumpers Revised (← links)
  • 05000259/LER-1989-007, :on 890305,when Diesel Generator Start Logic Energized,Diesel Generator Unexpectedly Started.Caused by Start Failure Relay Start Logic Not Reset After Earlier Logic Testing.Diesel Generator Shutdown (← links)
  • 05000370/LER-1989-009-04, :on 890901,inadvertent ESF Actuation Signal Generated Due to Personnel Removing Wrong Coil Wires Which Started motor-driven Auxiliary Feedwater Pump.Caused by Defective Procedure.Hot Wire Reinstalled (← links)
  • 05000313/LER-1988-025, :on 880307,reevaluation of Discrepancy Between Assumed Sys Flow Rates & Actual Rates During Reactor Bldg Purges Identified Twelve Releases from 1977-80 Which Exceeded Tech Spec Limits (← links)
  • 05000313/LER-1988-022, :on 881216,identified Discrepancy Which Resulted in Potential Impact on Environ Qualification of Plant.Caused by Failure to Properly Evaluate Changes in Svc Water Flow to DHR Coolers.Plan Developed (← links)
  • 05000368/LER-1989-004, :on 890301,discovered Plant Startup Procedure Inadequate Resulting in Inability to Automatically Transfer HPSI Pump Suction Prohibited by Tech Specs.Caused by Inadequate Procedure.Procedures Revised (← links)
  • 05000352/LER-1989-018, :on 890304,emergency Svc Water Pump C Started Twice During Installation of Mod & All Sys Actuated. Caused by Personnel Communication Error.Pump Secured & Declared Inoperable.Personnel to Be Counseled (← links)
  • 05000456/LER-1989-004-04, :on 890306,auxiliary Feedwater Pumps Started Automatically Following Closure of Governor Valves.Caused by Defective Test Switch.Stable Plant Conditions Established. Temporary Procedure Changes Initiated (← links)
  • 05000336/LER-1988-003, :on 880130,inadvertent Automatic loss-of-normal Power Actuation Occurred on Two of Engineered Safeguards Actuation Sys.Immediate Cause Not Apparent.Wiring Error Identified & Corrected (← links)
  • 05000271/LER-1989-022, :on 890831,identified That Outboard Isolation Valve V70-117 Fed from Nonemergency Power Bus.Exact Root Cause Unknown But Design Spec Misinterpretation Suspected. Temporary Mod Implemented (← links)
  • 05000333/LER-1998-004, :on 980501,initiated Manual Reactor Scram Due to Multiple Control Rod Drift Indications in Cr.Implemented Preventive Maint Evaluation for Control Rods & Similar Power Supplies to Determine Appropriate Preventive Maint Tasks (← links)
  • 05000293/LER-1989-026, :on 890830,automatic Scram Signal & Reactor Scram Resulted in turbine-generator Trip & Opening of 345 Kv Switchyard Air Circuit Breakers.Caused by Automatic Turbine Runback.Wiring to Relays Reversed (← links)
  • 05000461/LER-1998-004, :on 980127,identified Various Deficiencies in Installed SCR & Power Diodes of Division 2 Nsps Inverter. Caused by Ineffective & Inadequate Preventive Maint. Corrected Deficiencies & Calibr Inverter,Per 10CFR21 (← links)
  • 05000254/LER-1989-001-03, :on 890106,RCIC Pump Discharge Inboard Isolation Valve Failed to Open from Full Closed Position. Caused by Binding of Torque Switch on Valve Operator.Switch Replaced.Reportability Per Part 21 Possible (← links)
  • 05000254/LER-1989-002, :on 890109,total of Combined Local Leak Rate Test Interval on MSIV Exceeded Specified Surveillance Interval of 18 Months.Caused by Misinterpretation of Tech Specs.Tech Specs Revised (← links)
  • 05000354/LER-1989-017-01, :on 890830,reactor Scram Occurred Due to Result of Low Reactor Pressure Vessel Water Level Signal.Caused by Installation of Air Line Failure During Plant Const.Leak Check of All Soldered Connections Done (← links)
  • 05000456/LER-1989-009-05, :on 890902,failure of Main Steamline Safety Valve to Reseat Occurred.Caused by Preservice Error in Design of Valve.Vendor Recommended Upgrade Will Be Installed on Valve 1MSO17C.Remaining Valves Checked (← links)
  • 05000336/LER-1998-009-01, :on 980501,LBLOCA Analysis Indicates Peak Clad Temp Could Exceed 2200 Degrees F.Caused by Failure to Identify Excessive Variability.Reanalyzed LBLOCA Using Current & Corrected Evaluation Models (← links)
  • 05000313/LER-1989-002-01, :on 890120,reactor Trip Occurred Due to Failure in Main Generator Exciter & Two Reactor Coolant Pumps Tripped on Undervoltage When Bus H1 Failed to Fast Transfer to Offsite Power.Caused by Arcing in Exciter (← links)
  • 05000271/LER-1989-012, :on 890303,west Switchgear Room CO2 Suppression Sys Initiated Triggering Control Room Toxic Gas Monitoring Sys.Caused by Latches in 1 H Fire Barrier Doors Not Being Periodically Inspected for Proper Operation (← links)
  • 05000461/LER-1989-012, :on 890301,technicians Grounded & Reinstalled Logic Card After Receiving Unsatisfactory Test Results. Alarms Annunciated as Containment Isolation Valves Isolated.Caused by Inadequate Ground on Card (← links)
  • 05000366/LER-1989-005-03, :on 890903,feedwater Sys Master Controller Placed in Automatic Following Change from Single Element to Three Element Control,Controller Output Signal Suddenly Went to Zero.Caused by Component Failure (← links)
  • 05000499/LER-1989-020, :on 890829,all Three Operating Turbine Driven Feedwater Pumps Tripped.Caused by Momentary Interruption of Control Power to Feedwater Pump Overspeed Protection Circuits Due to Failure of Inverter (← links)
  • 05000259/LER-1989-014, :on 890606,diesel Generators 1B & 1D auto-started During Performance of Surveillance Procedure O-SI-4.9.A.3.a,resulting in Actuation of Esf.Caused by Personnel Error.Procedure Revised (← links)
  • 05000336/LER-1998-008-01, :on 980423,TS Violations Were Noted.Caused by Failure to Achieve Compliance to TS Requirements.Revised Appropriate Surveillance Procedures (← links)
  • 05000454/LER-1989-008-08, :on 890830,determined That Auxiliary Feedwater Pump Suction Pressure Switch Setpoints Not within Allowable Values.Root Cause Under Evaluation.Switch Setpoints Set to Conservatively High Values (← links)
  • 05000458/LER-1998-002-02, :on 980425,each of Two Trains of Annulus Mixing Sys Failed to Start During Testing Due to Different, Apparently Independent Causes.Eoi Personnel Performing Root Cause Analyses.Breaker Replaced (← links)
  • 05000219/LER-1989-007, :on 890306,secondary Containment Isolation & Standby Gas Treatment Sys Initiation Occurred Due to Electrical Ribbon Connection Disengaging from Socket.Caused by Equipment Failure.Mod Considered (← links)
  • 05000368/LER-1986-018, :on 860720,discovered Blowdown Pipe Missing Required Pipe Whip Restraint.Caused by Inadequate Control of Deviations from Design Requirements During Original Const. Pipe Whip Restraint Installed (← links)
  • 05000498/LER-1989-015-01, :on 890704,main Generator Output Circuit Breaker Opened Resulting in Reactor Trip.Caused by Failure of 125-volt Dc Generator Circuit Breaker Trip Circuit. Failed Relay Replaced (← links)
  • 05000293/LER-1986-010, :on 860415,unplanned Isolation of Primary Containment Isolation Sys Occurred Resulting in Closure of Eight MSIVs & Main Steam Outboard Drain Drive.Root Cause Undetermined.Loose Connections Reworked (← links)
  • 05000313/LER-1989-007-01, :on 890318,determined That Postulated Break in HPI Line Upstream of Hpi/Rcs Cold Leg Connection Could Constitute LOCA Not Enveloped by Plant Design Basis.Caused by Inadequate Design Change Process (← links)
  • 05000302/LER-1989-017, :on 890501,emergency Diesel Generator Started as Result from Inadvertent Operation of Manual Air Start Valve.Caused by Inadequate pre-job Briefing.Guards Placed Over Manual Air Start During Painting (← links)
  • 05000369/LER-1989-022-01, :on 890826,reactor Trip Occurred Because of Reactor Coolant Low Flow Signal That Interlocked W/ Permissive Signal.Caused by Equipment Failure/Malfunction. Recovery Procedure Implemented (← links)
  • 05000366/LER-1989-004-03, :on 890902,automatic Closure of Primary Containment Isolation Sys Valve 2E41-F002 Occurred Due to Isolation Signal.Caused by Personnel Error.Performance of Procedure Suspended.Procedure Revised (← links)
  • 05000483/LER-1989-011-01, :on 890905,ESF Containment Purge,Control Room Ventilation & Fuel Bldg Ventilation Isolations Received. Caused by Failed 15-volt Dc Power Supply in Train B ESF Cabinet.Power Supply Replaced & Tested (← links)
  • 05000259/LER-1988-035, :on 881021,unplanned Automatic Start of Train B of Control Room Emergency Ventilation Occurred.Caused by Procedural Inadequacy.Scheduling & Work Control Program Upgraded to Require Impact Evaluation (← links)
  • 05000322/LER-1989-006, :on 890707,hydraulic Transient Inadvertently Initiated Which Resulted in Automatic ESF & Reactor Trip. Caused by Personnel Error.Reactor Trip & Analog Trip Alarms Reset.Personnel Involved Counseled (← links)
  • 05000313/LER-1989-031, :on 890829,unexpected Control Room Isolation & Actuation of Control Room Emergency Ventilation Sys Occurred.Cause Undetermined.Further Investigation Into Cause Will Be Conducted (← links)
  • 05000374/LER-1989-011-03, :on 890826,spurious Reactor Protection Sys Actuation Occurred During Turbine Valve Leak Tightness Surveillance.Cause Not Found.Procedure Re Conduct of Operations Revised (← links)
  • 05000499/LER-1989-019, :on 890823,reactor Trip Occurred Due to Full Closure of Feedwater Isolation Valve During Partial Stroke Testing.Caused by Failure in Feedwater Isolation Valve Control Circuit.Troubleshooting Performed (← links)
  • 05000295/LER-1989-013-02, :on 890823,testing of Main Steam Safety Valves Revealed Majority of Valves Had Setpoints Low Outside +/- 1% Tolerance.Caused by Elevated Temps at Work Site.Plant Shut Down on 890826 & Instrumentation Evaluated (← links)
  • 05000445/LER-1998-004, :on 980427,failure to Perform Response Time Testing of Shunt Trip Feature of Reactor Trip Breaker.Caused by Failure to Recognize Difference in Functional Designs. Breaker Was Declared Inoperable & Test Was Performed (← links)
  • 05000271/LER-1989-008, :on 890307,primary Containment Isolation Sys Group Three Isolation Occurred.Caused by Personnel Error. Personnel Involved Made Aware of Occurrence & Specific Details of Sys Logic (← links)
  • 05000266/LER-1989-006, :on 890505,automatic Actuation of motor-driven Auxiliary Feedwater Pumps Occurred.Caused by Cognitive Personnel Error Concerning Projected Plant Conditions.Sys Response Evaluated (← links)
  • 05000368/LER-1988-023-01, :on 880219,inoperability of Mechanical Snubber on Main Steam Supply Piping Discovered.Caused by High Dynamic Loading of Piping & Snubber Due to Water Entrainment in Steam Piping.Snubber Replaced (← links)
  • 05000313/LER-1988-027, :on 880422,containment Isolation Valve Inoperable.Caused by Lack of Documentation of Design Basis Info for Sys Piping Temp & Pressures in Original Plant Design.Design Change Package Developed (← links)
  • 05000313/LER-1989-029, :on 890825,determined That Svc Water Sys Operating Procedure Allowed Operation of Sys in Configuration That Could Result in Sys Being Rendered Inoperable by Single Component Failure (← links)
  • 05000482/LER-1989-017, :on 890830,control Room Ventilation Isolation Signal Initiated When Chlorine Monitor Indicated High Level. Caused by Spurious Spike.Recorder Connected to Chlorine Monitor GK-AITS-3 to Monitor Channel Behavior (← links)
  • 05000368/LER-1986-017, :on 860604,discovered That Required Type C Testing of Containment Isolation Valves Not Performed Resulting in Noncompliance W/Tech Specs.Caused by Personnel Error.Actions Taken to Test Affected Valves (← links)
  • 05000313/LER-1989-004-01, :on 890120,high Pressure Injection Line Check Valve Failed to Reseat.Caused by Inadequate Design Change Process.Program of Visual Insp & NDEs Completed to Identify Any Sys Degradations Due to Thermal Stresses (← links)
  • 05000373/LER-1989-015-01, :on 890428,fire Protection Valves Found to Exceed Surveillance Frequency Requirements of Tech Specs 4.7.5.1.1.a/b.Caused by Error in Two Station Procedures. Procedures Revised (← links)
  • 05000368/LER-1989-003-01, :on 890216,personnel Determined That Valve Associated W/Train a Hydrogen Analyzer Exceeded Environ Qualification Parts Replacement Interval Since 1983.Caused by Personnel Error.Components Replaced (← links)
  • 05000260/LER-1989-020, :on 890702,logic Circuit Deenergized During Replacement of Fuse Resulting in Isolation of Reactor Zone Ventilation.Caused by Electricians Incorrectly Jumpering Fuse Prior to Removal.Instruction Revised (← links)
  • 05000416/LER-1998-002-01, :on 980421,failure to Maintain Standby DG Seismically Qualified as Required by TS Was Noted.Caused by Failure to Comply W/Sys Operating Instruction 04-1-01-P75-1. Door Was Closed Immediately (← links)
  • 05000306/LER-1998-002, :on 980201,defect in Primary Sys Pressure Boundary Was Observed on Motor Tube Base of Part Length CRDM Housing.Caused by Flaw on G9 Part Length Crdm.Unit 2 Part Length CRDMs Have Been Removed & Replaced (← links)
  • 05000271/LER-1998-011, :on 980422,noted That HPCI & RCIC Systems Low Steam Supply Pressure Isolation Function Is Bypassed During Startup Contrary to Ts.Cause Under Investigation.Will Revise Procedures Re HPCI & RCIC Steam Supply Valves (← links)
  • 05000368/LER-1989-008-01, :on 890506,overspeed Trip of Steam Turbine Driven Emergency Pump Occurred.Caused by Degraded Ramp Generator.Ramp Generator Replaced & Entire Speed Circuit Calibr (← links)
  • 05000368/LER-1988-016, :on 880920,Tech Specs Limit for Containment Spray Sys Train B Actuation Response Time Exceeded.Caused by Inadequate Procedures.Procedures for Routine Periodic Response Time Testing Revised for Discrepancy (← links)
  • 05000313/LER-1989-027, :on 890821,DHR/LPI Train B Injection Valve Removed from Svc for Maint W/O Being Demonstrated.Caused by Personnel Error & Inoperable Emergency Diesel Generator. Operator Counseled & Memo Issued (← links)
  • 05000369/LER-1989-019-01, :on 890821,inadvertent ESF Actuation Occurred Due to Inappropriate Action & Defective Procedure.Procedure Changes Completed for Train a & Train B Diesel Sequencer Timer Calibr Procedures (← links)
  • 05000458/LER-1989-008, :on 890225,reactor Automatically Scrammed While Performing Upper Thrust Bearing Wear Detector Test & RCIC Sys Injected Due to Spurious Low Reactor Water Level Signal. Turbine Bypass Switch Will Be Installed (← links)
  • 05000322/LER-1989-007, :on 890823,full Reactor Trip & Nuclear Steam Supply Shutoff Sys Actuation Occurred While Transferring Power Supply.Caused by Operator Error.Operations Personnel Instructed to Review Procedure (← links)
  • 05000259/LER-1989-024-02, :on 890826 & 0920,reactor Protection Sys Bus 1B Deenergized Resulting in Actuation of Plant Esfs.Caused by Inadequate Design of Protector Setpoints.Degraded Voltage Adjustment Potentiometer Replaced (← links)
  • 05000373/LER-1989-014-01, :on 890428,error in Reactor Bldg Ventilation Isolation Damper Indicating Light Circuit Logic Found.Caused by Inconsistency Between Drawings & Method of Timing Damper Closing.Damper Repaired & Circuitry Modified (← links)
  • 05000336/LER-1987-007, :on 870416,reactor Tripped Automatically Due to Turbine Trip Caused by Generator Exciter Field Breaker Opening.Caused by Generator Volts/Hertz Relay Actuation. Emergency Operating Procedure 2525 & 2526 Done (← links)
  • 05000374/LER-1988-014-01, :on 881017,Type B & Type C Total Containment Leakage Exceeded Tech Spec Limit of 0.6La in Hydrogen Recombined Gas Control Valve.Caused by Dirty Seats on Valve.Seats Cleaned & Lapped (← links)
  • 05000374/LER-1989-012-03, :on 890829,reactor Protection Sys Bus B Transfer Isolated,Causing Loss of Power to Shutdown Cooling Outboard Isolation Logic.Caused by Relay 2B21h-K35B Being Depressed Off Ctr.Isolation Logic Reset (← links)
  • 05000461/LER-1998-018, :on 980416,ESFA,occurred.Caused by Deficiencies in Method Used to Perform Nsps Power Supply Adjustment. Developed Maint Procedure for Replacement of Power Supplies Powered by Nsps Bus (← links)
  • 05000354/LER-1989-013-02, :on 890629,failure to Perform Required Local Leak Rate Testing on Hpci/Rcic Turbine Exhaust Vacuum Relief Piping Identified.Caused by Valves Not Being Included in Scope of Inservice Test Program (← links)
  • 05000301/LER-1989-004-01, :on 890820,reactor Tripped Following Turbine Trip Initiated by Generator Breaker Trip.Caused by Main Stepup Transformer Lockout & Loss of Electrical Load Due to Actuation of Relay.Transformer Returned to Svc (← links)
  • 05000423/LER-1998-016, :on 980223,potential Air/Gas Intrusion in Chemical & Volume Control Sys Was Noted.Caused by Inadequate Initial Design.No Cause for Corrective Actions Because Both Flow Paths Were Operable (← links)
  • 05000395/LER-1989-015, :on 890825,pressurizer Safety Valve Body Inlet a Temp Increased to Greater than 450 F & Plant Shutdown Initiated.Licensee Continuing to Evaluate Cause.Manual Reactor Trip Initiated (← links)
  • 05000267/LER-1989-017, :on 890818,wide Range Nuclear Channels III & V Upscaled & Tripped in Response to Induced Electrical Noise. Attempt to Locate Section of Cable Into Which Noise Being Induced Unsuccessful (← links)
  • 05000304/LER-1985-022-01, :on 851015,fuel Handling Accident Radiation Monitor Exceeded High Alarm Setpoint of 300 Mrem/H Due to High Exposure Rate from Upper Internals,Resulting in Closure of Containment Purge Valves.Procedure Revised.W/Undated Ltr (← links)
  • 05000155/LER-1989-008-01, :on 890822,reactor Pressure Increased Rapidly Causing Reactor Trip on High Neutron Flux.Caused by Rapid Closure of Turbine Admission Valves Due to Gross Leakage. Control Rods Inserted & Cooling Maintained (← links)
  • 05000395/LER-1989-004, :on 890302,component Cooling Water Pump Started as Result of Improper Maint Activity,Resulting in ESF Actuation.Caused by Personnel Error.Communication Re Properly Scheduling Maint Established (← links)
  • 05000304/LER-1989-008-07, :on 890624,breaker 27 Opened Causing Power Loss to NSSS Annunciators in Control Room.Caused by Binding of Breaker Mechanism Resulting in Insufficient Contact Pressure.Breaker 27 Removed & Replaced (← links)
  • 05000206/LER-1989-018, :on 890527,voluntary Entry to Tech Specs 3.0.3 Done to Perform Surveillance of Containment Spray Sys Pump. Caused by Inadequate Tech Specs (Ts).Ts 3.3.1 Rev Planned to Preclude TS 3.0.3 Entries for Similar Events (← links)
  • 05000336/LER-1989-005-02, :on 890330,automatic Test Insertion (ATI) Module Connector Did Not Mate Smoothly W/Engineered Safeguard Actuation Sys Cabinet Socket Resulting in Safety Injection Actuation Signal Actuation (← links)
  • 05000416/LER-1989-006, :on 890505,reactor Tripped on Low Reactor Water Level.Caused by Vessel Overfeed Due to Feedwater Heater Outlet Valves Not Fully Closed But Indicated as Closed. Design Changes to Feedwater Logic Evaluated (← links)
  • 05000368/LER-1987-010, :on 870522,plant Protection Sys Panels Seismic Qualification Compromised Due to Loose Fasteners.Caused by Personnel Error When Personnel Elected Not to Tighten All Screws.Personnel Counseled (← links)
  • 05000368/LER-1989-001-01, :on 890503,reactor Protective Sys Instrumentation Declared Inoperable Due to Channel Failing Low Intermittently.Caused by Misinterpretation of Procedure. Procedural Guidance Will Be Issued (← links)
  • 05000368/LER-1984-018, :on 840618,Train B of Sodium Hydroxide Addition Sys Discovered Inoperable During Monthly Surveillance Test. Caused by Personnel Error.Administrative Procedure Revised to Provide Clarification (← links)
  • 05000313/LER-1989-018, :on 890501,reactor Tripped & Inadvertently Jarred Turbine Control Panel Containing Mercoid Switches for Turbine Trip Functions.Caused by Caution Label Missing from Control Panel.Warning Placard Installed (← links)
  • 05000368/LER-1986-016, :on 860617,pressurizer Low Pressure Trip Remained Bypassed at Pressure Greater than Allowed.Caused by Personnel Error Resulting in Inadequate Procedure.Plant Protection Sys Calibr Procedures Revised (← links)
  • 05000373/LER-1989-016, :on 890502,Tech Specs Violated.Caused by Diesel Generator Surveillances Being Revised Incorrectly After Diesel Generator Prelube Mods Installed.On 890503,diesel Generator Would Not Shut Down (← links)
  • 05000304/LER-1989-006-06, :on 890426,discovered That power-range Nuclear Instrument Channel Defeated on Power Mismatch Switch,Rod Stop Bypass Switch & Upper & Lower Current Comparator Switches.Caused by Personnel Error (← links)
  • 05000029/LER-1989-007, :on 890423,control Rods Dropped & Automatic Reactor Scram Occurred as Result of Low Main Coolant Pressure.Caused by Broken Compression Connector on Motor Brake Solenoid Circuit.Control Rods Exercised (← links)
  • 05000461/LER-1998-019, :on 980417,noted Failure to Satisfy TS for Ensuring That Electrical Loads Properly Sequence Onto safety-related Buses.Caused by Inadequate Surveillance Procedures.Will Revise Procedures 9080.21 & 9080.22 (← links)
  • 05000424/LER-1988-025, :on 880731,lightning Struck Containment Bldg, Resulting in Reactor Trip.Caused by Electrical Surge from Lightning Strike Shutting Down Computers.Circuit Board in Security Sys Backup Computer Replaced (← links)
  • 05000425/LER-1989-019, :on 890502,overspeed Trip Device Malfunctioned During Weekly Turbine Trip Device Operability Test.When Button Pushed Turbine Tripped,Resulting in Reactor Trip. Caused by Defective Weld Joint.Weld Repaired (← links)
  • 05000425/LER-1989-008, :on 890319,automatic Feedwater Isolation Occurred Due to Steam Generator 4 Exceeding 78% hi-hi Water Level Setpoint.Caused by Operator Failure to Request Relief While Away from Post.Operator Counseled (← links)
  • 05000219/LER-1989-004, :on 890222,MSIV Automatic Closure Signal Occurred During Transfer of Reactor Protection Sys Power Supply.Caused by Procedural Inadequacy.Immediate Actions Taken to Open Valves & Revise Procedure (← links)
  • 05000354/LER-1989-005-01, :on 890301,isolation of RHR Loop Outboard Isolation Valve B Occurred During Surveillance Procedure. Caused by Noncognitive Personnel Error.Procedure Revised. Individuals Involved Counseled (← links)
  • 05000267/LER-1989-016, :on 890818,Loop II Shutdown Initiated by Plant Protection Sys Due to Low Bearing Water Surge Tank Level, Causing Water Pumps & Helium Circulators to Trip.Caused by Equipment Malfunction.Controller Replaced (← links)
  • 05000455/LER-1998-003-04, :on 980416,high RCS Activity & ESF Actuation Occurred.Caused by Inadequate RCS Cleanup & Weak Administrative Controls.Posted Area Surrounding Refueling Cavity as High Radiation Area (← links)
  • 05000293/LER-1989-021, :on 890615,automatic Actuation of Inboard & Outboard RWCU Sys Portion of Primary Containment Isolation Sys Occurred.Caused by Air in Sensing Lines of RWCU Sys Flow Sensors.Lines Bled to Eliminate Air (← links)
  • 05000265/LER-1988-007, :on 880413,determined That Measured Combined Leakage Rate from Penetrations & Valves Exceeded Tech Specs Limit.Caused by Normal Wear.Repairs & Replacements Completed as Necessary (← links)
  • 05000271/LER-1989-009, :on 890628,lack of Redundancy in RHR Svc Water Sys Discovered.Caused by Control Loop Functional Requirement Re Operation of Valve Not Properly Noted During Original Plant Design.Mod Made to Provide Power (← links)
  • 05000293/LER-1989-011, :on 890304,automatic Actuation of Portion of Primary Containment Isolation Control & Reactor Protection Sys Occurred During turbine-generator Coastdown.Caused by Turbine Bypass Valve Low Vacuum Trip (← links)
  • 05000304/LER-1989-007-02, :on 890428,discovered That Vent Stack Radiation Monitor Found in High Radiation Mode.Cause Unknown.Vent Stack Monitor Realigned to Normal Operation.Procedure Change Authorizes Performance of Surveillance (← links)
  • 05000368/LER-1986-015, :on 860801,review of Fire Barrier Penetration Log Identified 55 Penetrations Not Inspected within Tech Spec Required Interval.Caused by Inadequate Procedure & Personnel Error.Log & Test Procedures Revised (← links)
  • 05000369/LER-1989-009-01, :on 890421,ESF Actuation Occurred During Realignment of turbine-driven Auxiliary Feedwater Pump, Causing Pump Suction Pressure to Drop & Opening Valves. Caused by Improper Tagout Removal Procedure (← links)
  • 05000313/LER-1988-030, :on 890620,determined That Unacceptable Modeling Technique Used in Stress Calculations,Potentially Affecting Seismic Capabilities of Eccs.Mods of Affecting Piping Completed (← links)
  • 05000245/LER-1989-012, :on 890429,while Switching Reserve Stations Svc Transformer,Loss of Normal Power Occurred Prior to Deenergizing Transformer.Caused by Incomplete Undervoltage Load Shed Scheme.Scheme Modified (← links)
  • 05000313/LER-1988-020-01, :on 881103,nonsafety-related Ventilation Sys Affected Penetration Room Ventilation Sys Capability to Process Penetration Leakage Following Design Basis Accident. Caused by Failure to Assess Sys Impact (← links)
  • 05000263/LER-1998-002-02, :on 980415,main Steam Isolation Valve Position Setpoint Outside Allowed Range,Was Found.Caused by Previous Testing Technique & Use of Particular Switch Model.Eight New Position Switches W/Less Deadband Installed (← links)
  • 05000309/LER-1988-005, :on 880523,potential Harsh Environ Postulated for Unqualified Solenoid Valves.Emergency Operating Procedures Revised to Manually Isolate Vent Lines Following Safety Injection Actuation Signal (← links)
  • 05000352/LER-1989-043, :on 890628 & 29,refuel Floor HVAC Sys Isolated Due to Inadequate Differential Pressure Between Outside & Refuel Floor Atmospheres.Caused by Procedural Deficiency. Secondary Containment Isolation Switches Reset (← links)
  • 05000368/LER-1987-002, :on 870213,discovered Degraded Fire Barriers Due to Installation of Improper Seal Matl in Seismic Gap Separating Adjacent Bldgs.Caused by Inadequate Instructions During Const Phase.Fire Watch Established (← links)
  • 05000454/LER-1989-005-07, :on 890501,diesel Generator Failed to Load to 5,500 Kw within 60 Due to Deficient post-maint Testing. Caused by Max Fuel Setting on Fuel Control Sys Set Too Low. Fuel Control Sys Properly Adjusted (← links)
  • 05000263/LER-1998-003-01, :on 980417,transgranular Stress Corrosion Cracking Was Identified in Control Rod Drive Lines.Caused by chloride-induced Transgranular stress-corrosion Cracking. Affected Sections of Two Lines Replaced (← links)
  • 05000298/LER-1989-014, :on 890424 & 26,unplanned Actuation of Group 6 Isolation Occurred.Caused by Loose Terminal Board Connection.Loose Terminal Board Connection Retightened (← links)
  • 05000482/LER-1989-012, :on 890626,control Room Ventilation Isolation Signal Initiated When Control Room Air Intake Radiation Monitor GKRE-04 Experienced Loss of Power.Caused by Blown Fuse.Fuse Replaced (← links)
  • 05000259/LER-1989-017-02, :on 890701,potential Transformer Compartment Door on 4 Kv Shutdown Board B Fell Open Disconnecting Fuse & Cabinet Contacts.Caused by Door Latching Mechanism Failure. General Operating Instruction to Be Issued (← links)
  • 05000313/LER-1988-028, :on 880831,discovered That Piping Span Lengths Between Containment Bldg Penetrations & First Piping Supports Unacceptable.Caused by Inadequate Judgement of Original Designer.Piping Requalified (← links)
  • 05000267/LER-1989-007, :on 890421,main Turbine Generator Tripped Immediately Followed by Trip of Single Reactor Coolant Loop. Caused by Operator Error or Equipment Malfuction.Entire Bus Power Supply Sys Thoroughly Tested (← links)
  • 05000271/LER-1989-019, :on 890501,primary Containment Isolation Sys Group III & Standby Gas Treatment Sys Initiations Occurred. Caused by Reactor Bldg Ventilation Radiation Monitor Sensor Malfunction.Sensor/Converter Replaced (← links)
  • 05000382/LER-1989-017, :on 890819,automatic Reactor Trip of Unit Occurred While Operating at 23% Power.Caused by Equipment Malfunction.Repairs Made to Control Element Assembly Circuitry (← links)
  • 05000354/LER-1989-010-01, :on 890414,Tech Specs Requirement for Breaker Alignment Verification within One H of Declaring Emergency Diesel Generator Inoperability Missed.Caused by Supervisor Error.Incident Reviewed W/Personnel Involved (← links)
  • 05000354/LER-1989-011-01, :on 890427,high Radiation Area Not Properly Reposted Following Maint Per Tech Specs.Caused by Personnel Error.Exposure Doses for All Personnel Involved Reviewed & Safety Tagging Procedure Revised (← links)
  • 05000368/LER-1986-006, :on 860421,inadvertent Actuation of Reactor Protective Sys Occurred.Caused by Channel a Sys Departure from Nucleate Boiling Ratio & High Local Power Density Trip Functions Bypassed During Shutdown Operations (← links)
  • 05000331/LER-1989-006, :on 890224,isolation of RCIC & on 890302, Isolation of HPCI Occurred.Caused by Problems in Electrical Path from Thermocouples Monitoring Area Temp.Retermination of Broken Thermocouple Wire Before Break (← links)
  • 05000455/LER-1998-004-04, :on 980419,FHB Rad Monitor ESF Actuation, Occurred.Caused by High Dose Water in Fuel Transfer Canal. Fhb Dose Rates Monitored (← links)
  • 05000456/LER-1989-003-05, :on 890302,control Room Ventilation Actuations Due to Momentary Loss of Voltage to Radiation Monitors. Caused by Perturbation of 345 Kv Sys.Evaluation Performed on Area & Process Radiation Monitors (← links)
  • 05000368/LER-1986-020, :on 860712,discovered That Time Delay Function Associated W/Feeder Circuit Breaker from ESF Bus to Svc Water Pump Inoperable.Caused by Not Removing Jumper Wire. Jumper Wire Removed & Drawings Revised (← links)
  • 05000313/LER-1989-014, :on 890426 & 0504,control Room Emergency Ventilation Sys Automatically Actuated Nine Times as Result of Spiking of Radiation Monitor 2RE-8750-1.Detector Replaced & Bad Connection in Holder Repaired (← links)
  • 05000313/LER-1989-016, :on 890414,noted That Firewater Deluge Valve for Emergency Diesel Generator Not Repaired Since Crack Fitting Identified in Oct 1988.On 890201,sys Inoperable While Attempting to Replace Fitting (← links)
  • 05000313/LER-1989-013, :on 881025,anchor Support for Core Flood Tank (CFT) T2A Vent Line Not Seismically Qualified & Operability of CFT Could Not Be Assured.Caused by Missing Anchor Support.Anchor Support Modified (← links)
  • 05000374/LER-1989-009-03, :on 890619,RCIC Steam Line Hi Flow Isolation Switch Found to Have Diaphragm Leak.Probably Caused by Torn Diaphragm.Failed Switch Sent to Vendor for Detailed Insp. New Switch Installed (← links)
  • 05000373/LER-1989-010-01, :on 890303,setpoint Drift of Low Level Confirmed Automatic Depressurization Sys Permissive Switch Found in Excess of Reject Limit.Caused by Low Reactor Level During Reactor Scram.Mods Planned (← links)
  • 05000366/LER-1987-006, :on 870726,inadequate Design for Inverter Cooling Caused Power Failure Resulting in Reactor Scram. Caused by Equipment Failure Due to Inadequate HVAC Design. Inverter Refurbished (← links)
  • 05000321/LER-1987-011, :on 870723,reactor Water Level Decreased to Reactor Protection Sys Actuation Setpoint & Reactor Scram Occurred.Caused by Equipment Failure Due to Inadequate Ventilation Design.Inverter Refurbished (← links)
  • 05000368/LER-1989-010, :on 890425,discovered That Valve Stroke Surveillance Test for LPSI Sys & Refueling Water Tank Had Not Been Performed.Caused by Personnel Incorrectly Indicating Tests as Already Performed (← links)
  • 05000368/LER-1986-014, :on 860627,emergency Diesel Generator Failed. Caused by Engine Fuel Starvation Due to Severely Fouled Y- Strainer 2F-195B Screen Element.Mesh Screen Internals of Y-strainers Removed (← links)
  • 05000293/LER-1988-006, :on 880203,trip Signal Generated Unexpectedly from ATWS Div 2 Circuitry Resulting in Automatic Trip of Recirculation Sys Pumps & Subsequent Reactor Protection Sys Scram Signal.Cause Not Conclusively Determined (← links)
  • 05000259/LER-1998-001-03, :on 980414,standby Gas Treatment Sys HEPA Filter Testing Was Not in Compliance W/Ansi Std Requirements.Caused by Lack of Understanding of DOP Testing. Filter Testing Training Will Be Provided (← links)
  • 05000339/LER-1989-004-02, :on 890502,unexpected Automatic Reactor Trip Signal Generated During Performance of ICP-FW-2-F-2486. Caused by Procedure Inadequacy.Instrument Dept Procedures Will Be Reviewed & Revised (← links)
  • 05000483/LER-1989-002, :on 890228 & 0303,unplanned ESF Actuations Occurred.Caused by Shield Breakage of Coaxial Cable & Technician Inadvertent Push of ESF Actuation Push Button, Respectively.Cable Replaced (← links)
  • 05000368/LER-1984-015, :on 840302,discrepancy in Fire Barrier Penetration 2099-0002,which Previously Evaluated Acceptable, Identified as Nonfunctional.Caused by Lack of Definitive Guidelines in Walkdown Program (← links)
  • 05000368/LER-1989-007, :on 890424,snubber on Valve (2CV-4653) on Pressurizer Spray Line Found Disconnected While Performing Inservice Insp of Mechanical Snubbers.Caused by Inadequate Work Controls.Snubber on 2CV-4653 Replaced (← links)
  • 05000271/LER-1989-016, :on 890330,automatic Start of Core Spray & Sys a RHR Pumps Occurred While Pressurizing Primary Containment.Caused by Inadequate Procedure.Design Change That Implemented Logic Change Reviewed (← links)
  • 05000373/LER-1989-009-01, :on 890302,phase to Ground Fault Resulted in Generator Isolation.Caused by Failure Phase C Lightning Arrestor on Primary of Side of Station Auxiliary Transformer (← links)
  • 05000416/LER-1989-005, :on 890429 & 0508,RCIC Sys Isolated on Indicated High Steam Line Flow.Caused by Steam Line Pressure Transients,Resulting in Oscillations in Sensing Line. Procedure Re Instrument Calibrs Revised (← links)
  • 05000461/LER-1989-028, :on 890628,trip of Main Generator Resulted in Turbine Trip & Automatic Reactor Scram.Caused by Spurious Signal from Malfunctioning Sudden Pressure Sensor Relay. Relay Replaced W/One That Has Air Vent (← links)
  • 05000412/LER-1998-006-01, :on 980411,reactor Protection Sys Actuation Bypass Breaker Trip During 2MSP-1.14A Occurred.Caused by Procedure Error in Msp.Revised Maint Surveillance Procedures 2MSP-1.14A & 2MSP-1.14B (← links)
  • 05000265/LER-1989-004-08, :on 890811,atmospheric Containment Atmosphere Dilution Sys Unable to Perform W/Loss of Unit 2 Diesel Generator.Caused by Design Error.Procedure Changes to Alert Operators of Design Deficiencies Implemented (← links)
  • 05000271/LER-1989-020, :on 890811,procedure Controlling Battery Maint & Testing Discovered Not Consistent W/Tech Spec 4.10.2.a Requirements.Caused by Inadequate Tech Spec Review of Procedure Rev.Plant Procedure Revised (← links)
  • 05000313/LER-1989-012, :on 890402,discovered That High Energy Line Break Door Covered,Resulting in Condition Outside Design Basis of Main Feedwater Line Break in Piping Penetration Room.Caused by Personnel Error.Cover Removed (← links)
  • 05000373/LER-1994-015-01, :on 941212,PCI & Scram Due to Switch Failure Was Noted.Caused by Group 1 Isolation Signal Initiated by Spurious Trip.Replaced Switch (← links)
  • 05000245/LER-1996-023-01, :on 960306,movement of New Fuel Assemblies Over Spent Fuel Pool Resulted in Condition Outside of Design Basis of Plant.Caused by Personnel Error.New Fuel Elevator Tagged Out & Deenergized to Prevent Use (← links)
  • 05000352/LER-1989-016, :on 890228,manual ESF Actuation of Refuel Secondary Containment Isolation & Standby Gas Treatment Sys Occurred.Caused by Fuel Pin Dropped During Fuel Reconstitution Activities.Fuel Pin Retrieved (← links)
  • 05000499/LER-1989-014, :on 890418,loss of Offsite Power Occurred to Main & Auxiliary Transformers,Resulting in Loss of Power to Train a 4.16 Kv ESF Bus E2A.Caused by Loss of Switchyard Breakers Feeding Transformers.Meter Removed (← links)
  • 05000219/LER-1998-008, :on 980409,building Dp Was Found to Be Out of Design Requirements.Caused by Lack of Awareness.Operations Dept Tour Logs Were Revised to Require Orw Dp Readings to Be Taken Once Per Shift (← links)
  • 05000483/LER-1989-008, :on 890623,control Rod Bank B Failed to Move & Declared Inoperable in Mode 1.Caused by Failure of Flashover Relay Due to Loose Set Screw.Defective Rod Control Circuit Boards Replaced (← links)
  • 05000443/LER-1989-010, :on 890815,potential Transformer Fuse Cubicle for Emergency Bus E-6 Inadvertently Opened by Operator. Caused by Auxiliary Operator Error.Review of Tagging Order Performed & Operator Counseled (← links)
  • 05000382/LER-1998-009, :on 980415,inadvertent ESF Actuation Occurred. Caused by Inadequate Configuration Control.Restored Incorrectly Lifted Lead to Terminal Point & Made Maint Personnel Aware of Drawing Discrepancy (← links)
  • 05000304/LER-1989-051, :on 890624,power Lost to NSSS Annunciators in Control Room Due to Opening of Breaker 27.Caused by Binding of Breaker Mechanism Triggering Insufficient Contact Pressure.Breaker 27 Removed & Replaced (← links)
  • 05000313/LER-1989-017, :on 890420,discovered That Dhr/Low Pressure Injection Cooler Discharge Isolation Valves Not Tested Quarterly.Caused by Inadequate Mod Review Process.Provisions Made to Test Valves Every 3 Months (← links)
  • 05000311/LER-1989-013, :on 890610,reactor Trip Manually Initiated Due to Loss of Main Condenser on High Back Pressure.Caused by External Elements & Inadequate Corrective Action.Review of Preventive Maint History Conducted (← links)
  • 05000298/LER-1989-013, :on 890414,Div I Groups 2,3 & 6 Isolations Occurred Resulting in Closure Signals to Inboard Primary & Secondary Containment Isolation Valves.Caused by Human Factors Deficiencies.Wires Reconnected (← links)
  • 05000313/LER-1989-015, :on 861209,RCS Loop B Flow Transmitters Sensing Line Not Properly Supported.Cause Undetermined.Engineering Insp of Similar Components Conducted During 1R7 & Revealed No Other Discrepancies (← links)
  • 05000346/LER-1998-002, :on 980410,plant Tripped Due to High Pressurizer Level as Result of Loss of Letdow Capability. Makeup & Purification Demineralizer 3 Was Isolated Following Trip & Tagged OOS (← links)
  • 05000423/LER-1998-022, :on 980408,failure to Provide Operable Reactor Coolant Sys Loops in Mode 4 Occurred.Caused by Human Error. Operations Personnel Involved in Event Have Been Counseled (← links)
  • 05000373/LER-1989-022, :on 890810,RCIC Received Div I & Div II Isolation on RCIC High Steam Line Flow.Caused by Spurious High Steam Flow Signal.Rcic Sys Piping Integrity Verified & Isolation Logic Reset (← links)
  • 05000423/LER-1998-023, :on 980411,ESF Actuation Occurred at Millstone Unit 3.Caused by Failure of CR Operations Personnel to Diagnose S/G C Level Loss Resulting from Abnormal Sampling Blowdown Lineup.Operating Procedure Revised (← links)
  • 05000346/LER-1997-015, :on 971210,EDG Tachometer Circuit Was Noted Outside 10CFR50 App R Design Basis.Caused by Less than Adequate Development & Review of Mod 84-0183.Established Hourly Fire Watch in Cable Spreading Room (← links)
  • 05000499/LER-1989-012, :on 890414,radiation Monitor on Fuel Handling Bldg Exhaust Air Duct Went Into High Alarm & Actuated HVAC Sys.Caused by Clogged Filter on Radiation Monitor.Sample Lines from Duct to Monitor Will Be Checked (← links)
  • 05000499/LER-1989-013, :on 890415,reactor Trip Occurred & Train Reactor Trip Opened Unexpectedly.Cause Unknown.Reactor Brought to Orderly Shutdown.Reactor Trip Breakers & Asscociated Circuitry Tested (← links)
  • 05000346/LER-1997-008, :on 970318,inadequate Testing of safety-related Logic Occurred.Overall Root Cause Will Be Completed by 980930 & Results of Evaluation Will Be Reported in Suppl to LER (← links)
  • 05000455/LER-1989-003-04, :on 890227,containment Ventilation Isolation Occurred Due to Radiator Monitor Failure of Checksource Test.Caused by Faulty Detector.Detector Replaced & Monitor Tested & Returned to Svc (← links)
  • 05000368/LER-1989-006, :on 890418,high Pressure Turbine Extraction Ruptured Resulting in Reactor Trip on High RCS Pressure. Caused by Pipe Wall Thinning Due to erosion-corrosion. Defective Wiring Replaced & Sys Satisfactory (← links)
  • 05000260/LER-1989-006-02, :on 890331,reactor Protection Sys Deenergized, Resulting in ESF Actuations & Standby Gas Treatment,Control Room Emergency Ventilation & Refuel Zone Isolations.Caused by Personnel Standing on Breaker Cabinet (← links)
  • 05000313/LER-1989-025, :on 890623-0702,control Room Emergency Ventilation Sys Unexpectedly Activated Four Times.Caused by Induced Electrical Noise from Operation of Relays in Alarm Circuitry.Temp Instrumentation Repaired (← links)
  • 05000259/LER-1989-022-02, :on 890810,Train a of Control Room Emergency Ventilation Sys Actuated Due to Radiation Monitor Signal. Caused by Insertion of Radiation Detector Checksource. Monitor 3-RM-90-259B Functionally Tested (← links)
  • 05000213/LER-1998-001, :on 980409,seismic Monitor Sp Was Not in Compliance W/Ts.Caused by Inadequate Engineering Review. Submitted Proposed License Amend to Correct Issue (← links)
  • 05000331/LER-1998-003, :on 980410,invalid Esfas of Group III PCIS Was Noted.Caused by Procedure Deficiencies & Loss of Instrument AC Control Power.Revised Procedures & Reviewed Electrical Panel Labels & Associated Operating Procedures (← links)
  • 05000338/LER-1989-012-01, :on 890626,emergency Diesel Generator Inadvertently Started During Performance of Reactor Protection & ESF Response Time Testing.Caused by Personnel Error.Personnel Counseled (← links)
  • 05000461/LER-1998-015, :on 980405,ESF Actuation Was Noted.Caused by Shorted Diode in Nsps.Replaced Shorted Blocking Diode & Tested Other Diodes for Defects (← links)
  • 05000293/LER-1989-009, :on 890216,automatic Closing of Outboard RWCU Primary Containment Isolation Sys Occurred.Caused by RWCU Sys Flow Fluctuation.Inboard & Outboard RWCU Sys to Be Modified to Preclude Recurrence (← links)
  • 05000423/LER-1989-005, :on 890217,inadvertent Safety Injection Occurred on Train B.Caused by Personnel Error.All Operators Counseled on Importance of Being Cognizant of Actions When Manipulating Equipment (← links)
  • 05000445/LER-1997-004, :on 980408,issues Discovered During Review of GL 96-01 Associated W/Ts Surveillances.Caused by Inadequate Test Procedures.Revised Applicable Test Procedures to Include Testing When Alternate Power Is in Service (← links)
  • 05000456/LER-1989-005-06, :on 890422,instrument Inverter 111 Tripped & Repair Not Completed within 24 H Per Tech Spec.Caused by Shorted Capacitor Due to Normal Wear.Instrument Bus Energized & Inverter Repaired (← links)
  • 05000354/LER-1989-003-02, :on 890221,initiation of Invalid Channel B LOCA Signal During Testing Resulted in ESF Actuation.Caused by Momentary Failure in Test Equipment Circuitry,Causing Core Spray Logic to Lockup.Equipment Tested (← links)
  • 05000416/LER-1989-009, :on 890620,RCIC & RWCU Sys Isolated on High Steam Line Flow Signal & High Differential Temp,Respectively During Scheduled Maint.Caused by Personnel Error.Responsible Shift Superintendent Instructed (← links)
  • 05000219/LER-1989-005, :on 890217,standby Gas Treatment Sys & Partial Primary Containment Isolation Initiated During Time Tests. Caused by Fact That Sys Not Designed to Facilitate Testing. Blown Fuse Replaced & Isolation Signal Reset (← links)
  • 05000368/LER-1989-009-01, :on 890420,determined That Emergency Diesel Generator 18-month Test Procedure Did Not Verify Fuel Pump Transfer Capabilities.Caused by Personnel Error.Procedure to Be Revised (← links)
  • 05000295/LER-1989-008-06, :on 890620,inadvertent Start of Auxiliary Feedwater Pump Occurred Due to Distraction in Room.Caused by Personnel Error & Reversal Start/Stop Labeling on Pump Switch.Labeling Corrected (← links)
  • 05000368/LER-1989-015-01, :on 890809,personnel Identified Discrepancy Re Single Failure Design Criterion of Containment Hydrogen Analyzers.Caused by Inadequate Design Review Process. Evaluations Being Conducted to Correct Design (← links)
  • 05000458/LER-1988-024, :on 881027,ESF Actuation Occurred Resulting in Isolation of RWCU Sys.Caused by Cross Tripping Phenomenon of Temp Switches & Procedural Error.Changes Made to Surveillance Test Procedures (← links)
  • 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 (← links)
  • 05000254/LER-1989-004-07, :on 890417,reactor Manually Scrammed Due to Electromagnetic Relief Valve 1-203-3D Being Stuck Open. Caused by Steam Leakage Past Pilot Valve & Obstruction of Drain Orifice.Relief & Pilot Valves Replaced (← links)
  • 05000317/LER-1998-007, :on 980404,eight of Sixteen MSSVs on Unit 1 Lifted at Pressure Above Setpoint Required in Tech Specs During as-found Lift Test.Cause of Event Currently Under Investigation.Reset Failed Valves (← links)
  • 05000461/LER-1989-033, :on 890807,main Steam Line flow-high Signal Initiated Causing Isolation of Containment Isolation Valves. Caused by Failure to Recognize Extended Mode 3 Operation Problems.Procedure 3101.01 Revised (← links)
  • 05000456/LER-1989-007-08, :on 890810,containment Bldg Fuel Handling Incident Area Radiation Monitor Went Into Alert Alarm & Interlock Actuation Due to Loss of Pulses.Caused by Failed High Voltage Power Supply in Monitor (← links)
  • 05000278/LER-1988-003, :on 880520 & 22,primary Containment Isolation Sys Group III Inboard Isolation & Half Reactor Scram Occurred on Startup Feed,Resulting in Breaker Trip.Caused by Voltage Fluctuations.Breakers Reclosed (← links)
  • 05000271/LER-1989-021, :on 890725,containment High Range Radiation Monitor B Declared Inoperable Due to Failure to Respond. Caused by Open Circuit on Detector Signal Cable in Primary Containment.Instrument Will Be Repaired (← links)
  • 05000311/LER-1989-014-02, :on 890810,RMS Containment Particulate Monitor 2R12B Channel Failed & on 890823,monitor 2R41A Channel Failed.Caused by Design/Equipment Problems.Field Monitors Replaced as Needed (← links)
  • 05000346/LER-1989-004, :on 890411,determined That Break in nonsafety- Related Circulatory Water Line Could Cause Loss of All Svc Water Pumps.Caused by Significant Flow Path for Water Leak. Standing Order 89-026 Generated (← links)
  • 05000368/LER-1989-014-01, :on 870710,discovered That Portions of Piping & Supports,Associated W/Auxiliary Spray Piping Designed to Max Temp of 120 Degrees Instead of Possible Temp of 479 Degrees. Caused by Error in Analysis.Insp Performed (← links)
  • 05000458/LER-1989-019, :on 890411,unplanned ESF Actuation Occurred as Result of Blown Control Power Fuse During Surveillance Testing of Control Circuit.Cause Not Determined.Blown Fuse Replaced & Actuated Sys Restored to Normal (← links)
  • 05000457/LER-1989-001-09, :on 890223,loss of RHR 2B Loop Occurred as Result of Procedural Deficiency.Caused by Failure to Identify That Placing Ssps in Test Would Not Block auto- Closure of Pump Valves.Procedure Revised (← links)
  • 05000456/LER-1989-001, :on 890206,reactor Trip Occurred Due to Spurious Loss of Output Voltage on Instrument Inverter 112. Cause of Momentary Loss of Inverter Under Investigation. Feedwater Isolation Signal Reset (← links)
  • 05000254/LER-1989-010, :on 890629,reactor Scram Occurred Due to Turbine Stop Valve Closure.Caused by Loose Connection on Condenser Low Vacuum Pressure Switch Indicating Lamp 1-5600-PS-105B.Connection Tightened (← links)
  • 05000260/LER-1989-009-01, :on 890411,unplanned Scram & Main Steam Line Isolation Due to Spurious Spikes on Main Steam Line Radiation Monitors.Signal Cables from Radiation Monitors Disconnected to Prevent Spurious Trips (← links)
  • 05000499/LER-1989-018, :on 890802,control Room Ventilation Sys Actuated to Recirculation Mode as Result of High Level Trip of Vinyl Acetate Channel on Toxic Gas Analyzer.Caused by Failure of Positioner.Analyzer Replaced (← links)
  • 05000370/LER-1989-003-05, :on 890406,reactor Trip Occurred Due to lo-lo Level in Steam Generator 2C.Caused by Failure of Bellows in Positioner for Valve 2CF-20.Personnel Implemented Reactor Trip Recovery Procedure & Bellows Replaced (← links)
  • 05000338/LER-1989-010-01, :on 890416,normal Power Supply to 4,160-volt Emergency Buses 1H & 2J Lost When Lifted Wire Inadvertently Grounded During Removal for Switchyard Mods.Caused by Personnel Error.Rhr Pump B Restored (← links)
  • 05000305/LER-1989-009, :on 890401,during Repositioning of Ventilation Dampers,Jumper Inadvertently Detached from Terminal Block Contact,Causing Damper Actuation.Caused by Procedural Inadequacies.Weidmuller Blocks Installed (← links)
  • 05000245/LER-1998-005-02, :on 980330,loss of S1 & S2 Power Supply Were Noted Due to Single Failure.Caused by Inadequate Design & Indequate Mod Review.Abt & Breaker Configuration for MCC EF3 & MCC FE3 Will Be Evaluated (← links)
  • 05000352/LER-1989-014, :on 890216,isolation of Refuel Floor Secondary Containment & Initiation of Standby Gas Treatment Sys,Esf Occurred.Caused by Boiler Malfunction.Auxiliary Operator at Auxiliary Boiler Encl Restored Three Boilers (← links)
  • 05000333/LER-1989-013, :on 890803,two Solenoid Operated Group II Primary Containment Purge Sys Isolation Valves Closed.Caused by Technician Allowance of Jumper Wire to Contact Grounded Surface.Caution Statement Re Grounding Written (← links)
  • 05000499/LER-1989-011-01, :on 890410,reactor Trip & Safety Injection Actuation Occurred on Low Steam Line Pressure.Caused by Operator Skipping Two Steps in Heatup Procedure & Increasing RCS Pressure.Operator Counseled (← links)
  • 05000338/LER-1989-005-01, :on 890225,unit Tripped from 76% Power When Initiating Signal for Reactor Trip Was Greater than Feedwater Flow Mismatch Coincident W/Low Steam Generator Level.Caused by Closure of Regulating Valve (← links)
  • 05000321/LER-1998-002-03, :on 980406,unplanned Actuations of ESF Occurred.Caused by Blown Fuse.Blown Fuses Have Been Replaced (← links)
  • 05000354/LER-1989-004-01, :on 890222,inadvertent Alternate Rod Insertion Signal Initiated by Redundant Reactivity Control Sys.No Control Rod Motion Occurred.Caused by Deficient Procedure. Procedure Revised to Include Resetting of Trip (← links)
  • 05000277/LER-1989-008-01, :on 890415,incorrect Undervoltage Trip Fuses Placement by Operator Occurred Due to Inadequacy of Training Resulting in Isolation of RWCU Sys.Caused by Administrative Deficiency.Training Ltr Will Be Issued (← links)
  • 05000336/LER-1998-006-01, :on 980327,reactor Bldg Closed Cooling Water Sys Outside Design Upon Loss of Svc Water Occurred.Caused by Inadequate Consideration of All Postulated Single Failure Events.Procedures Will Be Implemented (← links)
  • 05000354/LER-1989-009-03, :on 890419,overvoltage Condition Affecting Class 1E Channel C Battery Charger Resulted in Loss of ECCS Instrumentation When Inverter Tripped.Caused by Personnel Error.Personnel Counselled (← links)
  • 05000482/LER-1997-018, :on 971001,multiple Failures of B Rhrp to Start Were Noted.Caused by Breaker Closing Circuit Not Achieving Continuity After Switch Was Actuated.Adjusted Breakers Positive Interlock Roller (← links)
  • 05000458/LER-1989-007, :on 890220,reactor Scram Occurred Due to Intermediate Range Monitor (IRM) Upscale Trip.Irm Upscale Trip Caused by Induced Positive Reactivity.Procedure GOP-001 Revised (← links)
  • 05000339/LER-1989-008-02, :on 890806,ESF Valve 2-RS-MOV-201B Inadvertently Closed During on-line Slave Relay Testing. Caused by Incorrect Interlock Identification for Valve.Valve Opened Following Testing of Slave Relay K645 (← links)
  • 05000354/LER-1989-016-01, :on 890802,discovered That Limit Switch Assembly on Primary Containment Instrument Gas Sys Valve Did Not Meet Requirements.Caused by Faulty Replacement in 1985. Environmentally Qualified Switch Installed (← links)
  • 05000293/LER-1998-006, :on 980331,failure to Comply W/Ts Limits on CR Worth Was Noted.Caused by Inadequate Verification & Control of Core Design Info.Ge Was Contacted to Perform Plant Specific Analysis for Current Cycle of Operation (← links)
  • 05000456/LER-1989-002-09, :on 890416,main Steam Line Low Pressure Reactor Trip,Safety Injection & Main Steam Isolation Occurred.Caused by RCS Pressure Above 1,1930 Psig & Main Steam Pressure Less than 640 Psig.Heatup Procedure Will Be Revised (← links)
  • 05000304/LER-1989-005-03, :on 890220,discovered That Tech Spec Action Statements Not Met for Inoperable Auxiliary Bldg Vent Stack Monitor.Monitor Inoperable Since 890219.Caused by Personnel Error.Procedures Will Be Revised (← links)
  • 05000313/LER-1989-009, :on 890224,control Room Emergency Ventilation Sys Unexpectedly Started.Cause Not Determined.Area in Vicinity of Chlorine Monitors Posted to Prohibit Use of Radios (← links)
  • 05000313/LER-1989-003, :on 880907,determined That Floor Penetration Located in Fire Barrier at Elevation 335 of Auxiliary Bldg Sealed Using Unqualified styrofoam-type Matl.Caused by Personnel Error.Penetration Seals Repaired (← links)
  • 05000498/LER-1989-011, :on 890412,actuation of Control Room Ventilation to Recirculation Mode Occurred.Caused by Inadequate Flow of Nitrogen Ref Gas Due to Design of Sys. Nitrogen Supply Will Be Upgraded (← links)
  • 05000374/LER-1989-008-05, :on 890614,sys Auxiliary Transformer to Bus 243 Closed Unexpectedly While Attempting to Parallel Diesel Generator 2B W/Offsite Power Source.Caused by Procedural Deficiency.Entire Generator Replaced (← links)
  • 05000309/LER-1989-002, :on 890214,identified That Heat Shrink Tubing Associated w/51 Connectors Not in Conformance W/Mfg Recommended Usage Range.Caused by Mfg Error.Connector Seals Repaired & Reactor Returned to Svc (← links)
  • 05000423/LER-1989-014, :on 890614,control Bldg Isolation Actuation Occurred.Caused by Procedural Inadequacy While Performing Refueling Surveillance of Reactor Protection Sys. Surveillance Procedure Revised (← links)
  • 05000424/LER-1989-016, :on 890708,manual Reactor Trip Occurred Due to Failure of Main Feedwater Isolation Valve.On 890803,loop 4 Main Feedwater Isolation Valve Spuriously Closed Resulting in Reactor Trip.Caused by Reduced Flow (← links)
  • 05000382/LER-1989-016, :on 890802 & 04,loss of Electrical Power to Fuel Handling Bldg Isolation Radiation Monitor Resulted in Automatic Starts of Train B Filtration Unit.Caused by Personnel Error.Electrical Power Restored (← links)
  • 05000352/LER-1989-048, :on 890801,various Primary & Secondary Containment Isolation Valves Received Isolation Signals. Caused by Instrumentation & Control Technician Error.Trip Signal & Associated Isolations Reset (← links)
  • 05000458/LER-1989-018, :on 890407,isolation of Div 2 Containment Ventilation Sys Occurred,Causing Tripping of Unit Fan Cooler & Isolation of Chilled Water Supply Valves.Caused by Operator Error.Venting Procedures Revised (← links)
  • 05000354/LER-1988-014-02, :on 880511,RWCU Loop Isolated on High Flow Differential ESF Signal During Pressurization of Filter/ Demineralizer.Caused by Design & Procedure Deficiencies. RWCU Sys Operation Procedure Revised (← links)
  • 05000293/LER-1989-020, :on 890614,unplanned Reactor Protection Sys Scram Signal Occurred During Shutdown.Caused by Operator Error.Responsible Operator Verbally Reprimanded for Failing to Follow Approved Procedure (← links)
  • 05000458/LER-1989-029, :on 890613,unplanned ESF Actuation Occurred as Result of Technicians Shorting Two Leads Together While Installing Spare Transformer.Caused by Personnel Error. Communications Improved (← links)
  • 05000260/LER-1989-006-01, :on 890331,unplanned ESF Actuations Occurred Due to Loss of Reactor Protection Sys Motor/Generator Output.Caused by Personnel Standing on Breaker Cabinet. Scaffold Const Procedure Revised (← links)
  • 05000454/LER-1988-005-01, :on 880804,two Stability Trip Enable Annunciators Actuated Simultaneously in Main Control Room & Output Breakers Opened.Caused by Microwave Noise on Circuit Communicating Grid Status.Power Restricted (← links)
  • 05000425/LER-1989-001-02, :on 890214,control Room Isolation Occurred Due to Spurious Signal from Radiation Monitor Channel.Caused by Random Failure of Component in Data Processing Module. Radiation Monitor Repaired & Observed (← links)
  • 05000461/LER-1989-032, :on 890731,operators Initiated Manual Scram Due to Difficulties W/Moisture Separator Reheater & High Pressure Feedwater Heater Sys.Caused by Personnel Error. Operators Provided W/Details of Event (← links)
  • 05000271/LER-1989-018, :on 890413 & 17,technician Discovered Locked High Radiation Area Door 10 Open During Regularly Scheduled Plant Workdown.Caused by Failure to Properly Train Plant Personnel.Doors Closed & Locked (← links)
  • 05000304/LER-1984-004, :on 840120,vendor Informed That Auxiliary Feedwater Valve Setting Insufficient to Insure RCS Cooling. Existing FSAR Analyses Had out-dated Info.Operators Instructed to Raise Feedwater Flow (← links)
  • 05000374/LER-1989-007-06, :on 890612,unit Sys Auxiliary Transformer Deluge Sys Inadvertently Actuated.Inadvertent Actuation Being Investigated.Actuation Tentatively Attributed to Electrical Malfunction.New Bushing Installed (← links)
  • 05000454/LER-1989-007-07, :on 890803,lightning Caused Transmission Line 0622 to Trip & Initiated Voltage Transient on Electrical Sys.Transmission Line Repaired & Mod Installed in Radiation Monitors (← links)
  • 05000461/LER-1989-020, :on 890415,determined That Polarity of Test Equipment Connections to Digital Signal Conditioner Pins Reversed.Caused by Failure to Investigate Consequences of Shorting Pins.Supervisor Counseled (← links)
  • 05000311/LER-1989-013-01, :on 890610,control Room Alarm Annunciated Due to High Differential Pressure & Reactor Tripped Resulting in in Five of Six Circulating Pumps Becoming Inoperable.Caused by Inadequate Corrective Action (← links)
  • 05000461/LER-1989-018, :on 890414,high Neutron Flux Signal Occurred on intermediate-range Monitor C & intermediate-range Monitor D Tripped.Caused by Recessed Connector Pin for Monitor C Signal Lead.Pin Repaired & Operators Briefed (← links)
  • 05000483/LER-1989-004, :on 890517,feedwater Isolation Signal Occurred Due to Water Level in Steam Generator a Increasing to High Level Trip Setpoint.Caused by Failure to Adequately Equalize Pressure Across MSIV Prior to Opening Valves (← links)
  • 05000455/LER-1989-001-12, :on 890211,safety Injection Actuation of Train a & B Equipment Occurred During Performance of Diesel Generator Operability Test.Caused by Inadequate Precautions in Surveillance Test.Procedures Revised (← links)
  • 05000311/LER-1989-009-01, :on 890415,RMS Plant Vent Noble Gas Monitor channel,2R41C,indicated Communication Failure.Caused by Design/Equipment Problem.Back Plane Contacts on All Modules in Local & Remote Channel Monitor Cleaned (← links)
  • 05000311/LER-1989-008-02, :on 890411,reactor Trip on Steam Generator 24 lo-lo Level Occurred After Main Steam Line Isolation Valve 24MS167 Closed.Caused by Latching Relay Failure During Surveillance.Relay Replaced & Circuit Tested (← links)
  • 05000425/LER-1989-018, :on 890422,feedwater Isolation Occurred Due to Turbine Trip from Loss of Stator Cooling Water.Caused by Procedure That Allowed Reactor Power to Rapidly Drop to Level Too Difficult to Control Steam Generator (← links)
  • 05000254/LER-1989-003-07, :on 890412,manual Reactor Scram Initiated Due to Main Turbine Bypass Valves Opening.Caused by Component Failure.Circuit Board Replaced (← links)
  • 05000483/LER-1989-007, :on 890612,auxiliary Feedwater Actuation of motor-driven Auxiliary Feedwater Pump a Occurred.Caused by Inappropriate Human Performance on Part of Licensed Reactor Operator.Event Discussed W/Licensed Operators (← links)
  • 05000313/LER-1988-024, :on 881219,DHR Sys Inboard Suction Valve Closed,Resulting in Loss of DHR Sys Flow.Caused by Inadvertent Jarring of Panel Housing Control Relays for Suction Valve.Caution Label Placed on Panel (← links)
  • 05000029/LER-1989-005, :on 890406,reactor Was Manually Tripped When Main Steam Line 1 Isolation Valve Inadvertently Closed. Caused by Technician Performing Routine Surveillance Test Missing One Step.Technicians Counseled (← links)
  • 05000354/LER-1989-008-01, :on 890410,non-Q-listed Temp Switch Discovered Installed in Control Room Emergency Filtration Sys Chiller. Caused by Personnel Error.Train Declared Inoperable & Proper Temp Switch Obtained & Installed (← links)
  • 05000293/LER-1989-024, :on 890726,automatic Actuation of Outboard RWCU Sys Portion of Primary Containment Isolation Control Sys Occurred.Caused by Trip Signal from Outboard RWCU Sys Flow Sensor.Testing Planned for Addl Data (← links)
  • 05000423/LER-1989-013-01, :on 890608,Train a Loss of Power Signal Initiated from Emergency Diesel Generator a Panel.Caused by Replacement of Control Power Fuse in Train a Undervoltage Auxiliary Circuit.Personnel Counseled (← links)
  • 05000443/LER-1989-007-06, :on 890610,ESF Actuation Occurred Causing Containment Ventilation Sys to Isolate.Caused by Faulty Geiger-Muller Tube.Defective Tube Replaced & Monitor Tested & Declared Operational on 890611 (← links)
  • 05000336/LER-1988-011, :on 881025,loss of Normal Power on Both 4160-volt Vital Ac Buses Caused Reactor Trip & ESF Actuation.Caused by Personnel Error.Procedure Rewritten to Assure Proper Use of Ground & Test Devices (← links)
  • 05000245/LER-1989-005-01, :on 890407,reactor Scram Occurred on Turbine Stop Valve Closure.Caused by Failure of Moisture Separator Normal Drain Valve a to Maintain Normal Level in Moisture Separator Drain Tank.Valve Rebuilt (← links)
  • 05000267/LER-1989-010, :on 890607,automatic Shutdown of Loop I RCS Initiated by Plant Protective Sys.Caused by Degradation of Module FM-2205-8 Resulting in Excessive Amperage Through Power Supply Circuit.Blown Fuse Replaced (← links)
  • 05000265/LER-1989-001-11, :on 890406,reactor Scram Occurred Due to Turbine Stop Valve Closure.Caused by Failure of Pilot Solenoid Valve in de-energized Condition.Solenoid Rebuilt & Coil & Limit Switch Replaced (← links)
  • 05000295/LER-1989-008-03, :on 890609,identified That Potential Problem Exists Re Svc Water Sys Ability to Supply Both Room Coolers W/Current Piping Configuration.Caused by Design Deficiency. Safety Significance for Subj Room Cooler Being Evaluated (← links)
  • 05000254/LER-1989-007-05, :on 890609,refuel Floor 1A Radiation Monitor Spiked High Causing Reactor Bldg Vents & Control Room HVAC to Isolate & auto-start.Caused by Faulty Geiger Mueller Tube in Monitor.Monitor Repaired & Tested (← links)
  • 05000352/LER-1989-021, :on 890329,isolation of Refuel Floor Secondary Containment & Initiation of Standby Gas Treatment Sys Occurred.Caused by Improperly Operating Pneumatic Controller for Damper Positioner.Controller Replaced (← links)
  • 05000498/LER-1989-013-01, :on 890607,unplanned ESF Actuation of Fuel Handling Bldg HVAC Sys to Filtered Exhaust Mode Occurred. Caused by Personnel Error.Technicians Counseled on Radiation Monitoring & Bulletin Issued (← links)
  • 05000455/LER-1989-001-02, :on 890211,safety Injection Actuation of Trains a & B Equipment Occurred.Caused by Inadequate Precautions in Surveillance Procedure.Procedures Used for Diesel Generator Operability Test Will Be Revised (← links)
  • 05000424/LER-1989-017-01, :on 890728,radiation Monitor ARE-2532B High Alarm Setpoint Resulted in Fuel Handling Bldg Isolation. Cause Unknown.Alarm Setpoint Raised & Procedure 35611-C Revised Re Panel Operating Steps (← links)
  • 05000245/LER-1989-006-01, :on 890407,drywell Leakage Rate Exceeded 2.5 Gallons Following Reactor Scram.Caused by Packing Leak on Inboard Main Steam Drain Line Isolation Valve.New Valve Packing Program Implemented (← links)
  • 05000219/LER-1988-022, :on 881002,power to 4,160 Volt Bus 1D Was Lost When Breaker 1D Tripped & Locked Out Due to Ground Fault. Caused by Isolated Defect in Cable Insulation.Cable Replaced (← links)
  • 05000029/LER-1989-010, :on 890724,identified That Potential Existed for Exceeding 400 Kw Capacity of Emergency Diesel Generator 3.Caused by Pump Operation in Cavitation.Administrative Controls to Be Added to Existing Procedures (← links)
  • 05000298/LER-1989-012, :on 890407,actuation of ESF Group Isolations Occurred Subsequent to Planned Manual Scram.Caused by design.State-of-the-art Digital Turbine Control Sys Being Installed (← links)
  • 05000458/LER-1989-028, :on 890512,particulate Channel of Fuel Bldg Exhaust Radiation Monitor Spiked Resulting in Automatic Initiation of Fuel Bldg Filter Trains.Caused by Degraded Voltage Conditions Due to Electrical Outage (← links)
  • 05000304/LER-1988-011-01, :on 881111,incorrect Installation of Wires on Second Level Undervoltage Contact Resulted in Inability of 480-volt Transformer Feed Breaker to Close.Caused by Inadequate Mod Testing.Wiring Corrected (← links)
  • 05000309/LER-1989-003, :on 890405,plant Trip Occurred When Generator Protective Relays Actuated on Loss of Load Condition to Trip Reactor & Turbine.Caused by Personnel Error.Procedures Will Be Changed (← links)
  • 05000277/LER-1989-015-01, :on 890721,main Turbine Bypass & Control Valves Opened,Causing Main Steam Line Pressure to Decrease to Approx 480 Psig & Full Reactor Scram.Caused by Malfunction of Pressure Regulator Set.Component Replaced (← links)
  • 05000458/LER-1989-014, :on 890405,operator Inadvertently Initiated Standby Svc Water Sys During Svc Water Vacuum Release Valve Testing,Causing CRD Pump to Trip.Caused by Operator Error. Operator Reinstructed Re Board Manipulations (← links)
  • 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 (← links)
  • 05000295/LER-1988-012-01, :on 880617,determined That 20 Valves Failed 1% Setpoint Pressure Tolerance as Required by Tech Spec Table 4.7-1.Caused by Setpoint Drifting Between Calibr Testing or by Testing Method.Valves Overhauled (← links)
  • 05000313/LER-1989-021, :on 890601,inadvertent Main Steam Line Isolation Occurred During Maint.Caused by Defective Instrument Modules.Defective Modules Replaced & Affected Channels Tested (← links)
  • 05000313/LER-1989-024, :on 890309,incorrect Trip Coil Installed in Power Supply Feeder Breaker for Motor Actuator for Emergency Feedwater Sys Train a Isolation Valve to Steam Generator B. Caused by Personnel Error.Plant Mod Improved (← links)
  • 05000499/LER-1989-009-01, :on 890405,reactor Trip & Loss of Offsite Power on Auxiliary Buses & 4.16-kV Train a ESF Bus Occurred, Resulting in Actuation of Auxiliary Feedwater.Caused by Improper Installation of Relay Wiring (← links)
  • 05000425/LER-1989-024, :on 890726,failure of Pressure Channel Circuit Card Caused Reactor Trip.Caused by Failure of Operational Amplifier in non-isolated Section of Process Card.Defective NLP2 Card Replaced (← links)
  • 05000368/LER-1989-011-01, :on 890608,discovered That Fire Door Separating Plant Fire Areas Being Propped Open W/O Fire Watch Stationed as Required by Tech Specs.Caused by Personnel Error.Fire Door Opened.Periodic Training Provided (← links)
  • 05000295/LER-1989-012-02, :on 890723,auxiliary Feedwater Pump Declared Inoperable Due to Failing Trip Test.Caused by Administrative Error Re Plant Interpretation of Applicable Tech Spec.Proper Flow Settings Valved In.Procedure Revised (← links)
  • 05000483/LER-1989-003, :on 890331,feedwater Isolation & Auxiliary Feedwater Actuation Occurred Due to High Water Level in Steam Generator A.Caused by Personnel Failure to Curb Steam Generator Level Increase.Training Provided (← links)
  • 05000254/LER-1989-006-08, :on 890605,recirculation Pump Tripped Due to Operation of Wrong Breaker While Searching for Grounds. Caused by Personnel Error.Individual Counseled on Need for Correctness in Executing Procedures (← links)
  • 05000416/LER-1989-010, :on 890722,reactor Automatically Scrammed Due to High Neutron Flux Signal on APRMs & RCIC Automatically Actuated.Caused by Severe Electrical Storm Passing Over Station.Channel Check of APRM Indications Done (← links)
  • 05000373/LER-1989-009, :on 890302,phase to Ground Fault Occurred at Phase C Lightning Arrestor on Primary Side of Sys Auxiliary Transformer.Caused by Phase to Ground Fault That Occurred from Lightning Arrestor Due to Blown Debris (← links)
  • 05000395/LER-1989-006, :on 890401 & 0330,turbine Trip Occurred Due to High Moisture Separator Reheater Level.Caused by Various Secondary Equipment Malfunctions.Reactor Trip & Trip Recovery Procedures Implemented (← links)
  • 05000425/LER-1989-015, :on 890405,07 & 09,feedwater Isolation & Auxiliary Feedwater Actuations Occurred.Actuations on 890405 & 09 Due to Faulty Circuit Boards on Solid State Protection Sys Logic Circuits.Boards replaced.W/890501 Tr (← links)
  • 05000271/LER-1989-013, :on 890310,while Stroking Suction Valves for RHR a & C Pumps,Gravity Drain Path Created from Reactor Vessel to Suppression Chamber.Caused by Personnel Error.Rhr Operating Procedures Revised Re Loop Isolation (← links)
  • 05000373/LER-1989-021, :on 890609,RCIC Outboard Isolation Valve Failed to Open.Caused by build-up of Corrosion Products Between Stem & Stem Nut Causing Breaker to Trip.Valve Operator Disassembled,Inspected & Repaired (← links)
  • 05000304/LER-1985-029-01, :on 851201,containment Purge Inlet & Outlet Isolation Valves & Air Exhaust Stack Radiation High Annunciator Alarmed.Caused by Spurious Spike on Monitor 2RT-PR09C.Value of Capacitor Changed (← links)
  • 05000425/LER-1989-016, :on 890411,unplanned Auxiliary Feedwater Actuation Occurred on Recovery from Remote Shutdown Test. Caused by Actuation Not Being Anticipated by Procedures. Procedures Will Be Revised (← links)
  • 05000265/LER-1989-003-09, :on 890529,loss of Secondary Containment Occurred During Search for Grounds on 125 Volt Dc.Caused by Inadequate Design of 647 Ft Elevation Interlock Doors. Interlock Doors Closed.Procedures Revised (← links)
  • 05000499/LER-1989-016, :on 890602,reactor Trip Occurred on Completion of Two Out of Four Logic for Closed Turbine Inlet Throttle Valves.Caused by Deficient Test Procedure.Turbine Inlet Valve Test Procedure Revised.Part 21 Related (← links)
  • 05000458/LER-1989-027, :on 890528,automatic Initiation of Standby Svc Water Pump Occurred During Surveillance Test Procedure. Caused by in-process Surveillance Test Deenergizing Div III 480/120 Volt Ac Bus.Procedure Revised (← links)
  • 05000373/LER-1989-013-01, :on 890331,suppression Chamber High Level Alarm Exceeded Tech Spec Alarm Setpoint.Caused by Procedural Inadequacy.Switch 1E22-N002A Calibr (← links)
  • 05000454/LER-1989-004-06, :on 890328,diesel Generator 1A Failed to Start During Monthly Operability Surveillance.Caused by Excess Binding Fuel Supply Controls.Injection Pump Metering Rod Cylinders Cleaned & Free Motion Verified (← links)
  • 05000245/LER-1989-015, :on 890602,reactor Scram Occurred During Startup Due to Condenser Low Vacuum.Caused by Personnel Error.Operations Dept Instruction 1-OPS-2.01 Revised.Event Discussed in Detail W/Operators Involved (← links)
  • 05000423/LER-1989-017, :on 890718,motor-operated Isolation Valve for Containment Recirculation Spray Header Inoperable for 27 H. on 890717,dual Position Indication Observed in Control Board.Caused by Inadequate Guidance (← links)
  • 05000293/LER-1989-023, :on 890718,manually Initiated Reactor Protection Sys Scram Signal & Reactor Scram Occurred, Resulting in turbine-generator Trip & Transfer of Electrical Loads.Procedure Re Air Ejector Revised (← links)
  • 05000458/LER-1989-012, :on 890325,ESF Isolation Occurred for RWCU Main Steamline Drains & RHR Shutdown Cooling Sys.Caused by Loss of Power to Div II Isolation Logic When Breaker Opened. Breaker Reclosed (← links)
  • 05000313/LER-1989-023, :on 890605,determined That Power Range Nuclear Instrumentation Calibr Required by Tech Specs Had Not Been Performed within Specified Frequency.Caused by Lack of Procedural Guidance.Procedure Revised (← links)
  • 05000259/LER-1989-014-02, :on 890606,diesel Generators 1B & 1D auto- Started During Performance of 0-SI-4.9.A.3.a.Caused by Personnel Error.Procedure Immediately Revised to Include Precautionary Note Re Insulation of Terminals (← links)
  • 05000352/LER-1989-038, :on 890528,RCIC Sys Isolated & RCIC Turbine Received Trip Signal from Steam Leak Detection Sys High Differential Temp Isolation Signal.Caused by Procedural Noncompliance.Technicians Disciplined (← links)
  • 05000295/LER-1989-007-04, :on 890311,RHR Supply to Train a Containment Spray Header Stop Valve Did Not Fully Open While Performing PT-2B Step A.5.Caused by Boric Aid Buildup on Valve Stem. Valve Stem Cleaned & Lubricated (← links)
  • 05000313/LER-1989-020, :on 890530,manual Actuation of Emergency Feedwater Pump Occurred.Caused by Tube Failures in Feedwater HX & Leaking B Startup Control Valve Which Necessitated Opening of Valve FW-8B.Tube Leaks Repaired (← links)
  • 05000368/LER-1989-012-01, :on 890626,RCS Backleakage Through Safety Injection Sys Check Valve Occurred Three Times.Caused by Missing Internal Parts.Cause of Missing Rollpins Could Not Be Determined.Rollpins Replaced (← links)
  • 05000483/LER-1989-006, :on 890529,reactor Trip Occurred on Power Range Neutron Flux Rate Trip Signal.Caused by Lack of Detail Provided in Plant Procedures.Procedure ESP-ZZ-00006, Incore /Excore Calibr Revised (← links)
  • 05000260/LER-1989-017, :on 890607,intermediate Range Monitors C,G & H of Neutron Monitoring Sys Received hi-hi Signal.Caused by Failure to Implement Action to Disable Tungsten Inert Gas Auto Start Function.Memo Issued to Managers (← links)
  • 05000482/LER-1989-014, :on 890718,control Room Ventilation Isolation Signal Initiated by Spike on Control Room Air Intake Radiation Monitor.Caused by Voltage Transient Associated W/ Lamp Burning Out.Monitor Restored (← links)
  • 05000282/LER-1989-009-01, :on 890718,alarm Indicating Chlorine Gas Present in Control Room Ventilation Intake Duct Received & Control Room Cleanup Fan Automatically Isolated.Caused by Monitor Generating False Signal.Cells Cleaned (← links)
  • 05000456/LER-1989-006-09, :on 890718,lightning-induced Voltage Transients Experienced,Resulting in Actuation of Multiple Rod Drive Overvoltage Protection Devices.Caused by Inadequate Lightning Protection.Protectors Reset (← links)
  • 05000425/LER-1989-023, :on 890720,reserve Auxiliary Transformer 2A Tripped on Differential Relay Lockout,Resulting in Loss of Power to Train a Bus 1E & non-1E Buses.Caused by Improper Termination of 4,160-volt Bus (← links)
  • 05000457/LER-1989-003-01, :on 890322,centrifugal Charging Pump 2B Manual mini-flow Isolation Valve Mispositioned.On 890601, Recirculation Flow Read Zero.Caused by Personnel Error. Locked Equipment Program Will Be Revised (← links)
  • 05000293/LER-1989-017, :on 890520 & 21,unplanned Actuations of Same Portion of RHR Sys/Lpci Loop Selection Logic Circuitry Occurred While Shutdown.Caused by Engineer Error.Testing Suspended & Affected Components Restored (← links)
  • 05000293/LER-1989-018, :on 890525,automatic Actuation of Outboard RWCU Sys Portion of Primary Containment Isolation Control Sys Occurred.Caused by Air in Instrumentation Sensing Line of RWCU Sys Flow Sensor.Procedures Revised (← links)
  • 05000461/LER-1989-022, :on 890526,insertion of Manual Scram Signal Caused Reactor Water Level to Drop.On 890601,valve 1FW004 Failed to Shut in Response to Control Signal.First Event Caused by Faulty servo-amplifier Board (← links)
  • 05000461/LER-1989-030, :on 890715,scram Signal Initiated When RHR Shutdown Cooling Valves Opened,Decreasing Reactor Water Level.Caused by Failure to Repair Seat Leakage Promptly. Maint Work Request to Repair Valve Performed (← links)
  • 05000282/LER-1989-006-01, :on 890526,alarm Indicating Chlorine Gas Present in Control Room Ventilation Intake Duct Received & Control Room 122 Cleanup Fan Automatically Started.Caused by Jamming of Paper Tape in Monitor (← links)
  • 05000306/LER-1989-002-01, :on 890526,unit Tripped on Steam Generator Low Level.Caused by Failure of Electrolytic Capacitor & Inductor.Speed Error Amplifier Card Replaced & Insp of All Other Circuit Cards Completed (← links)
  • 05000425/LER-1989-014, :on 890403,test Signal Incorrectly Applied to Input of Steam Generator Dump Control Circuit Caused Feedwater Isolation.Caused by Error in Procedure Which Reversed Polarity of Applied Test Signal (← links)
  • 05000245/LER-1989-004-02, :on 890328,standby Gas Treatment Sys Automatically Initiated & Reactor Bldg Ventilation Sys Isolated.Caused by High Radiation Signal from Ventilation Exhaust Radiation Monitor.Tube Replaced (← links)
  • 05000499/LER-1989-017, :on 890713,internal Fault Occurred in Main step-up Transformer 2A.Caused by Failure of Phase a High Voltage Bushing in Transformer.Transformer Returned to Mfg for Repair & Further Failure Analysis (← links)
  • 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 (← links)
  • 05000352/LER-1989-045, :on 890716,radiation Monitor Indication Drifted Above Isolation Setpoint of 1.35 Mr/H Causing ESF Actuation. Caused by Equipment Failure.Radiation Monitor Declared Inoperable & Isolation Reset (← links)
  • 05000353/LER-1989-003-02, :on 890717,full Reactor Protection Sys Scram Signal Initiated by Upscale Trip of Intermediate Range Monitor B.Caused by Faulty Preamplifier.Scram Signals Reset & Portions of post-scram Procedure Done (← links)
  • 05000424/LER-1989-013-01, :on 890530,dissolved Gases Came Out of Solution & Actuated High Radiation Signal & Fuel Handling Bldg Isolation Occurred.Caused by Inadequate Procedure. Appropriate Procedure Revised (← links)
  • 05000416/LER-1988-012, :on 880518,unit Tripped on APRM Neutron Flux High Signal.Caused by Spike to Grounding Strap for Plant Security Fence Located on Roof of Turbine & Control Bldgs. Grounding Strap Relocated (← links)
  • 05000373/LER-1989-020, :on 890529,unit 250 Volt Dc Main Feed Circuit Breaker to Bus 121Y Failed During Manual Closure Attempt, Rendering RCIC Sys Inoperable.Caused by Failure of Main Feed Circuit Breaker.Closing Mechanism Repaired (← links)
  • 05000346/LER-1989-005, :on 890530,unit Experienced Reactor Trip from 100% Power Due to Loss of Condenser Vacuum.Caused by Failed Splice in One Phase of 13.8 Kv Feeder Cable.Faulty Load Cable Isolated & Unit Restarted (← links)
  • 05000295/LER-1989-011-02, :on 890712,several Containment Isolation Valves Inadvertently Actuated When Test Switch Removed from Test Position.Caused by Personnel Error.Operator Training & Procedure Revised (← links)
  • 05000277/LER-1989-012, :on 890519,reactor Hi Lo Level Alarm Sounded & Reactor Feed Pumps B & C Tripped Simultaneously.Caused by Failure of Feedwater Level Control Switch.Switch Replaced, Amplifier Replaced & Procedures Revised (← links)
  • 05000311/LER-1989-006-02, :on 890329,reactor Trip Signal on Steam Generator 21 Occurred After Shutdown for Compliance W/Tech Spec Action Statement 3.7.7.b.Caused by Equipment Problems. Channel I Transmitter Recalibr (← links)
  • 05000354/LER-1989-015-01, :on 890713,discovered That Monthly Functional Test of HPCI Sys Div 1 Steam Leak Detection Temp Switch Not Performed Since 890317.Caused by Problems Encountered During Recovery from Computer Malfunction (← links)
  • 05000456/LER-1988-002-04, :on 880125,reactor Trip & Safety Injection Generated During Performance of Instrument Surveillance Analog Operational Test & Channel Verification/Calibr.Caused by Personnel Error.Test Rept Revised (← links)
  • 05000456/LER-1988-021-01, :on 880926,verified That Monthly Target Axial Flux Surveillance Not Performed.Caused by Personnel Error & Lack of Administrative Controls.Reduced Power to Less than 90% & Calculated New Target Values for Delta I (← links)
  • 05000382/LER-1989-013, :on 890719,rapidly Decreasing Level Observed in Steam Generator 1 Resulting in Manual Reactor Trip.Caused by Circuit Failure in Position Control Circuitry.Circuit Card W/Failed Component Replaced & Sys Restored (← links)
  • 05000295/LER-1989-006-04, :on 890328,reactor Protection Loop Inoperable & Untripped for More than 2 H.Caused by Personnel Error. Event Discussed W/Appropriate Personnel & 5-day Training Course Attended (← links)
  • 05000313/LER-1989-011, :Between 890326 & 0421,control Room Emergency Ventilation Sys (CREVS) Unexpectedly Automatically Actuated 13 Times.Caused by Spiking of Radiation Monitor & Inadequate Corrective Actions from Previous Events (← links)
  • 05000301/LER-1989-002, :on 890329,unit Experienced Main step-up Transformer Lockout Main Generator Breaker Trip & Concurrent Turbine & Reactor Trips.Caused by Wiring Error in Terminal Box 2-TB69.Repairs Completed (← links)
  • 05000354/LER-1989-007-01, :on 890406,Tech Spec 3.0.3 Entered Due to Inoperability of Both Control Room Emergency Filtration (CREF) Units.Caused by Unrelated Equipment Failures in CREF a & B Trains.Failed Seal Replaced in Train a (← links)
  • 05000354/LER-1989-012-02, :on 890607,HPCI Sys Declared Inoperable Due to Steam Supply Valve Packaging Leakage on Outboard Steam Supply Isolation Valve.Caused by Compression of Packing During Normal Packing Gland Adjustments (← links)
  • 05000298/LER-1989-019, :on 890524 & 0609,Group 1,3 & 6 Isolations Occurred Due to Design Change Activities.Caused by Human Factors & Communications Deficiencies.Further Guidance Incorporated in Dc Instructions (← links)
• 05000458/LER-2015-001, Operations Prohibited by Technical Specifications Due to Deficient Local Leak Rate Test Procedures Containing Erroneous Valve Alignments (← links)
• 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications (← links)
• 05000458/LER-2015-003, Operations Prohibited by Technical Specifications and Loss of Safety Function Due to Inoperability of Division 2 Containment Penetration Leakage Control System (← links)
• 05000483/LER-2015-004, Auxiliary Feedwater Control Valve Inoperable Due To Faulty Electronic Positioner Card (← links)
• 05000483/LER-2015-001, Completion of a Shutdown Required by the Technical Specifications - TS 3.4.13 (← links)