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| Issue date | Title | Topic | |
|---|---|---|---|
| ML17335A764 | 22 October 1998 | LER 98-004-00:on 980923,inadvertent Actuation of Efs Occurred During Surveillance Testing.Caused by Personnel Error.Personnel Involved with Event Were Counseled & Procedure Changes Were Implemented.With 981022 Ltr | |
| ML19207B884 | 28 August 1979 | LER 79-059/03L-0:on 790730,during Mode 1 Operation,Power Supply Failed Causing Isolation of Control Room Ventilation. Caused by Circuitry Failure.Power Supply Was Repaired, Operationally Checked & Radiation Monitor Returned to Svc | |
| ML19207B885 | 28 August 1979 | LER 79-013/03L-0:on 790808,decay Heat Boron Concentration Was Not Monitored During Prescribed Interval & Inservice Decay Heat Loop Was Switched W/O Switching Sample Lineup. Caused by Communications Breakdown Between Depts | |
| ML19208A102 | 5 September 1979 | LER 79-068/03L-0:on 790812,emergency Feedwater Flow Control Valve 2CV-1025-1 from Pump 2P7B to Steam Generator a Failed to Fully Close from Control Room Demand Signal.Caused by Nonalignment of Limit Stop Switch.Switch Realigned | |
| ML19208A103 | 5 September 1979 | LER 79-067/04L-0:on 790808,auxiliary Bldg Radwaste Area Radiation Monitor 2RE-E542 Sample Pump Found W/Broken Coupling.Cause Not Stated.Plastic Coupling Replaced W/Metal Coupling.Appropriate Grab Samples Taken | Grab sample |
| ML19208A104 | 5 September 1979 | LER 79-064/03L-0:on 790807,trips in Plant Protection Sys D Placed in Bypass to Investigate Oscillations in delta-T Power Indication.Caused by Cold Leg Temp Indication Oscillation.All Related Signal Connections Tightened | |
| ML19208A105 | 5 September 1979 | LER 79-069/03L-0:on 790814,diesel Generator 2 Could Not Be Stopped from Control Room Handswitch 2HS-2829-2 During Mode 2 Operation.Caused by Internal Spring on Handswitch Contact Being Out of Adjustment.Spring & Switch Contacts Adjusted | |
| ML19208A739 | 31 August 1979 | LER 79-063/03L-0:on 790806,containment Atmosphere Sample Reactor Bldg Penetration Outside Isolation Valve 2SV-8263-2 Would Not Indicate Closed During Stroke Test.Caused by Limit Switch Being Out of Adjustment.Limit Adjusted | |
| ML19208A750 | 31 August 1979 | LER 79-065/03L-0:on 790809,battery Charger 2D31 Failed, Rendering Dc Bus a Inoperable.Caused by Dc Output Lamp Socket Burning Up Due to Higher Voltage & Increased Resistance in Circuit.Unit Cleaned | |
| ML19208A757 | 31 August 1979 | LER 79-066/03L-0:on 790809,containment Isolation Valve 2CV-2201-2 Would Not Fully Close After Routine Draining of Reactor Drain Tank.Caused by Foreign Matl Damaging Seats & Ball,Resulting in Valve Leaking Through.Valve Cleaned | |
| ML19208A787 | 31 August 1979 | LER 79-012/03L-1:on 790810,during Cold Shutdown,Testing of Reactor Bldg Penetration V-1 Showed Leak Rate Exceeding 50,000 Cc/Minutes.Caused by Isolation Valve CV-7402 Needing Adjustment of Shims on Seat to Match Butterfly Surface | |
| ML19208D453 | 20 September 1979 | LER 79-058/03X-1:on 790724,as Result of Analysis of Seismic Category I Pipe Supports,Nine Restraints Were Identified as Having Safety Factor of Less than Two.As Result,Reactor Bldg Sump Drain Declared Inoperable | |
| ML19208D461 | 20 September 1979 | LER 79-076/03L-0:on 790821,control Room Emergency Air Conditioning Unit 2VE1B Failed to Start.Caused by Crankcase Oil Leak.Leak Repaired,Oil & Freon Added | |
| ML19208D464 | 20 September 1979 | LER 79-077/03L-0:on 790826,safety Injection Tank 2T2D Level Could Not Be Maintained Above 80.1% Due to Makeup Valve 2CV-5064 Failing to Open on Command.Caused by Improper Spring Tension on Valve Operator Gate.Tension Adjusted | |
| ML19208D472 | 14 September 1979 | LER 79-015/99X-0:on 790817,as Result of Analysis of Seismic Category I Pipe supports,37 Restraints Were Identified to Have Safety Factor of Less than Two.Supports Modified | |
| ML19208D479 | 14 September 1979 | LER 79-016/03L-0:on 790827,diesel Generator 2 Tripped on Low Oil Pressure,Rendering Generator Inoperable.Caused by Leak Allowing Water to Enter Oil Sys,Causing High Crankcase Pressure.Oil Cooler Replaced | |
| ML19210C711 | 12 November 1979 | LER 79-086/03L-0:on 791013,during Mode 6 Operation,Increased Radiation Monitor Indication Noted on Shutdown Cooling Heat Exchanger 2E35B.Caused by Small Tube Leak in Heat Exchanger. Anomalies Will Be Analyzed | |
| ML19210D114 | 14 November 1979 | LER 79-019/03L-0:on 791012,condensate Isolation Valve CV-1065 to Quench Tank Failed to Close from Control Panels C-16 & 18.Caused by Burnt Out Solenoid Coils.Replaced AC Coils by Coils & Tested Valve | |
| ML19210D370 | 16 November 1979 | LER 79-020/04L-0:on 791017,excessive Radioactive Gas Release Occurred During Routine Makeup Tank Gas Space Sampling. Caused by Increase in Failed Fuel.Sampling Temporarily Discontinued & Procedures Being Revised | |
| ML19210D575 | 7 November 1979 | LER 79-018/03L-0:on 791008,tank Discharge Valve Failed & Control Valve 1616 Declared Inoperaple.Caused by Pinched Control Wire Blowing Fuse in Breaker Cubicle.Wire Reinsulated & Fuse Replaced.Craft Personnel Cautioned | |
| ML19211A252 | 6 December 1979 | LER 79-021/03L-0:on 791115,while Securing Makeup & Purification Sys,Inside Containment Isolation Seal Return Valve Failed to Fully Close on Demand.Caused by Valve Operator Torque Switch Failing to Make Up.Switch Replaced | |
| ML19211A255 | 6 December 1979 | Updated LER 79-012/03X-1:on 790810,leak Rate Testing of Reactor Bldg Purge Valves at Penetration V-1 Indicated Leak Rate in Excess of Tech Spec Limits.Caused by Maladjusted Valve Seat Shims.Leak Rate Test Performed | |
| ML19211A262 | 6 December 1979 | LER 79-087/03L-0:on 791114,during Mode 5 Operation,Leakage Discovered in Socket Weld on Low Pressure Safety Injection Flow Orifice Valve.Caused by Mechanical Fatigue Failure at Weld.Injection Sys Out of Svc 3-h During Repair | |
| ML19211A264 | 6 December 1979 | LER 79-039/03X-1:on 790527,during NRC Audit of Category E Valve Positions in Mode 3 Operation,Low Pressure Safety Injection Discharge Header Valve 2SI-5091-3 Found Closed. Caused by Operator Error.Valve Modified | |
| ML19225B033 | 16 July 1979 | LER 79-007/03L-0 on 790616:during Heatup,Emergency Feedwater Pump Automatically Started W/Inadvertent Actuation.Caused by Valve Lineup Error.Outboard Pump Bearing Found to Be Hot Due to Faulty Installation.Maint Procedure Revised | |
| ML19225C431 | 18 July 1979 | LER 79-046/03L-0 on 790619:leakage of Seal on Personnel Escape Hatch Was in Excess of 50,000 Cubic Centimeters/ Minute.Cause Not Given.Seal Replaced.Retest Indicated No Leakage | |
| ML19225C797 | 27 July 1979 | LER 79-009/03L-0 on 790628:during Power Operation Reactor Bldg Hydrogen Purge Fan VSF-30A Tripped After 90 Minutes of 10-h Run.Caused by Overcurrent.Fan Restarted Using Less Sealing Water | |
| ML19225C811 | 27 July 1979 | LER 79-010/01T-0 on 790714:design of Main Steamline Restraints Did Not Consider Steam Hammer Transient Forces. Review Performed.Overstressed Area Will Be Modified | |
| ML19225C819 | 27 July 1979 | LER 79-047/04L-0 on 790627:condenser Vacuum Pump Radiation Monitors Inoperable More than Seven Days During Mode 1 Operation.Caused by Moisture Buildup.Engineering Evaluation Is Being Conducted | |
| ML19241A687 | 27 June 1979 | LER 79-040/03L-0 on 790603:during Mode 3 Operation, Emergency Feedwater Valve from Electric Pump to B Steam Generator,Would Not Stroke Shut.Caused by Coil & Tripper Bar Being Out of Adjustment.Valve Repaired | |
| ML19241A693 | 27 June 1979 | LER 79-043/03L-0 on 790609:during Mode 3 Operation, Emergency Feedwater Control Valves from Electric Pump to a Steam Generator Failed to Close.Caused by Loose Wire on Handswitch.Valve Filled & Vented W/Oil | |
| ML19241B164 | 6 July 1979 | LER 79-041/03L-0 on 790607:failure to Perform Surveillance Test on Containment Personnel Hatch within Specified Time Limit.Caused by Irregularity of Testing on Weekends.Testing Rescheduled to Fall on Monday,Wednesday & Friday | |
| ML19241B165 | 6 July 1979 | LER 79-042/03L-0 on 790607:reheat Stop Valve 4 Would Not Open During Mode 1 Operation W/Main Turbine Latched. Caused by Mechanical Binding of Reheat Stop Valve to Seat. Valve Freed & Trip Tested | |
| ML19241B166 | 6 July 1979 | LER 79-037/03L-1 on 790514:supply Valves 2CV-1039-2 & CV-1076-2 to Steam Generator 2E24B Would Not Respond During Mode 3 Operation.Caused by Blown Fuse & Stuck Relay.Repairs Made & Valves Proven Operable | |
| ML19242A182 | 25 July 1979 | LER 79-008/03L-0 on 790621:emergency Feed Actuation Received When once-through Steam Generator a Startup Level Transmitter Selection Was Shifted.Caused by Overspeed Trips Due to Water in Steam Supply Line | |
| ML19246B518 | 9 July 1979 | LER 79-044/03L-0 on 790610:valve Operator Tripped Circuit Breaker on Overload & Affected Containment Penetration Automatic Isolation Valve Deactivated in Closed Position. Caused by Valve Shaft Binding in Packing.Valve Tested | |
| ML19246B520 | 9 July 1979 | LER 79-045/03L-0 on 790613:channel a Core Protection Calculator Taken Out of Bypass,Resulting in Linear Power Density & DNBR Trip.Cause Unknown.Channel Tested & Returned to Svc | |
| ML19248C810 | 26 June 1979 | LER 79-039/03L-0 on 790527:during NRC Audit of Category E Valve Positions,While in Mode 3 Operation,Low Pressure Safety Injection Discharge Header Valve 25I-5091-3 Was Discovered in Closed Position.Cause Unstated.Valve Opened | |
| ML19248C815 | 26 June 1979 | LER 79-038/03L-0 on 790527:during Main Steam Safety Valve Testing in Mode 3 Operation,Steam Generator a Pressure indicator,2PI-1041-4 on Channel Dpps,Failed High.Caused by Heat Breakdown of Some Component | |
| ML19249B533 | 30 August 1979 | LER 79-060/03L-0:on 790802,failure of Reactor Drain Tank 2T68 Discharge Reactor Bldg Penetration to Close from Control Signal.Caused by Crystallization of Boron in Vent on Valve Operator Piston.Valve Cleaned & Returned to Svc | |
| ML19249B536 | 30 August 1979 | LER 79-061/03L-0:on 790804,failure of Low Pressure Nitrogen Supply in Reactor Bldg Penetration,Outside Isolation Valve, to Close on Control Signal.Caused by Limit Setpoint Drift. Limit Adjusted & Valve Returned to Svc | |
| ML19249B554 | 30 August 1979 | LER 79-062/03L-0:on 790804,failure of Full Length Control Element Assembly 39 to Move.Caused by Failed Control Element Assembly Enable Card.Card Replaced & Assembly Declared Operable within 1-h of Failure | |
| ML19249C764 | 12 September 1979 | LER 79-014/99X-0:on 790813,w/75% Reactor Power,Switchyard Relay 21Z1 Failed,Causing Turbine Trip.Caused by Lug Failure on Terminal Leads to Turbine Lockout Relay 286-T.Failed Lug Replaced,Terminals Tightened & Turbine Interlocks Tested | |
| ML19249C774 | 12 September 1979 | LER 79-070/03L-0:on 790816,during Mode 1 Operation,Battery Eliminator 2D35 Failed,Causing Reactor Trip Breakers to Open.Caused by Relay Coil Failure Due to Sticking Plunger. Relay Replaced & Breakers Reclosed | |
| ML19249C778 | 12 September 1979 | LER 79-071/03L-0:on 790818,during Mode 1 Operation,B Core Protection Calculator Failed.Caused by Memory Failure. Memory Module Replaced,Software Loaded,Core Protection Calculator Functionally Tested & Returned to Svc | |
| ML19249C779 | 12 September 1979 | LER 79-074/03L-0:on 790821,during Mode 1,core a Projection Computer Trips Bypassed,Allowing Change Out of Power Supplies & Causing Erroneous Position Indication Inputs.Core a Projection Computer Supplies Replaced | |
| ML19249C780 | 12 September 1979 | LER 79-072/03L-0:on 790818,following Plant Trip,Emergency Feedwater Pump Turbine Driver 2K3 for Pump 2P7A Tripped on Overspeed.Caused by Sticky Linkage on Turbine Governor.Trip Reset & 2P7A Sucessfully Tested | |
| ML19249C781 | 12 September 1979 | LER 79-075/03L-0:on 790822,during Mode 1,data Link to Core B Projection Computer Dropped Bit,Causing Inaccurate Output. Caused by Failed Optical Amplifier.Data Link Repaired & Returned to Svc | |
| ML19249C782 | 12 September 1979 | LER 79-073/03L-0:on 790820,during Mode 1 Operation,Spurious Control Element Assembly Calculator Penalty Factor Outputs Caused Reactor Trip.Caused by Dirty Input Card Contacts.Edge Connector Cleaned & Calculators Verified Operable | |
| ML19250A492 | 19 October 1979 | LER 79-080/03L-0:on 790921,indication for Sodium Hydroxide Addition Tank Discharge Valve 2CV-5667-2 Was Lost.Caused by Failed Power Supply Fuse.Power Fuse Was Replaced & Control Circuit Current Verified |