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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20045A4291993-06-0303 June 1993 LER 93-003-00:on 930505,new Source of Natural Gas Introduced within 0.5 Miles of ISFSI & Reactor Bldg W/O Prior NRC Approval.Caused by Field Routing of Natural Gas Pipe.Well Isolated by Well operator.W/930603 Ltr ML20043E0991990-05-31031 May 1990 LER 89-018-01:on 890827,cracking Found in Incoloy Alloy 800 Main Steam Ringheaders & Condition Determined to Have Generic Implications.Caused by Creep Failure.Main Steam Ringheaders repaired.W/900531 Ltr ML20042G4211990-05-10010 May 1990 LER 90-001-00:on 900410,non-essential Bus 5,4160/480-volt Transformer N-9215 Experienced Fault.Caused by Breakdown of Insulation on Secondary Coils of Transformer.Coils of Transformer rewound.W/900510 Ltr ML20011D4641989-12-20020 December 1989 LER 89-014-01:on 890818,four Fire Barrier Penetration Seals in Bldg 10 Did Not Meet Foam Seal Structure Criteria of Seal Spec.Caused by Improper Curing During Installation.Fire Watch Established & Seals repaired.W/891220 Ltr ML20024E0021983-07-29029 July 1983 LER 83-023/03L-0:on 830701 & 02,emergency Feedwater Unavailable to Drive Loop I Helium Circulation Water Turbines.Caused by Normal Wear of Valve PV-21243.Valve Internals Replaced & Valve calibr.W/830729 Ltr ML20024B9861983-07-0101 July 1983 LER 83-020/03L-0:on 830604,emergency Feedwater Header Supply to Loop I Helium Circulator Turbine Water Drive Isolated & Bearing Water Make Up Pump Taken Out of Svc.Caused by Flexitallic Gasket Failure Due to Normal wear.W/830701 Ltr ML20024A8521983-06-22022 June 1983 Updated LER 80-041/03X-2:on 800724,one of 12 Helium Circulator Seal Malfunction Pressure Differential Switches Discovered W/Trip Point Outside Tech Spec Limits.Caused by Dirt Accumulation in Electrical switches.W/830622 Ltr ML20023D9021983-05-26026 May 1983 LER 83-017/01T-0:on 830512,insp Performed Per IE Bulletin 83-03 Identified Six of Eight Check Valves Frozen in mid- Position.Caused by Corrosion & Rusting Valve Internal Parts. Valves Cleaned & Internal Components Replaced ML20028G2831983-01-28028 January 1983 LER 82-053/03L-0:on 821229,fuel Storage Well Pressure Exceeded Atmospheric Pressure While Reactor Was Shut Down. Caused by One Gas Compressor Being Out of Svc for Maint and Other Pumping Less than Capacity.Compressors Repaired ML20028G2711983-01-28028 January 1983 LER 82-054/03L-0:on 821229,outlet Temps Exceeded 120 F Limit When Reactor Became Critical During Isolation of Svc Water Flow to Pcrv Cooling Water Hx.Caused by Lack of Cooling Source.Design Change Initiated ML20028F2401983-01-19019 January 1983 LER 82-051/03L-0:on 821220,during Surveillance Test,One of Six Steam Pipe Rupture & One of 12 Steam Pipe Rupture Channels Identified Inoperable Due to Low Response to Calibr Noise.Caused by Failure of Resistor ML20028F2881983-01-17017 January 1983 LER 83-001/01T-0:on 830101 & 02,reactor Operated W/O Min Number of Operable Moisture Monitor Channels Required Per Table 4.4.1 of Limiting Conditions for Operation.Caused by Personnel Misinterpretation of Tech Specs ML20028A3101982-11-10010 November 1982 LER 82-042/03L-0:on 821013,unplanned Radioactive Gas Release Occurred W/Reactor Shutdown & Depressurized.Caused by High Airborne Activity in Reactor Bldg Due to Leaking Blank Flange.Emergency Procedures Initiated.Flange Repaired ML20028A2861982-11-10010 November 1982 LER 82-041/03L-0:on 821011,during Calibr of Radioactive Liquid Effluent Monitors,Trip Point for RIS-6212 Found to Be Less Conservative than Required.Caused by Instrument Drift. High Voltage & Discriminator Settings Adjusted ML20023A7451982-10-0808 October 1982 LER 82-036/03L-0:on 820908,one of Two Bearing Water Makeup Pumps Removed from Svc.Caused by Need to Rebuild Mechanical Seal Due to Normal Wear.Seal Rebuilt ML20052H9881982-05-12012 May 1982 LER 82-011/03L-0:during 820412-20,plant Operated in Degraded Mode of Limiting Conditions for Operation 4.2.11 Three Times & 4.2.10 Once.Caused by Offgas of Moisture from Core as Plant Returned to Power from Maint Outage ML20052H8751982-05-12012 May 1982 LER 82-013/03L-0:on 820412,separation in Axial Positions of Two Partially Inserted Control Rod Groups Fell Slightly Below Limit of 10 Ft.Cause Not Stated.Control Rods Repositioned ML20052G4151982-05-10010 May 1982 LER 82-012/03L-0:on 820410,at 10% Power,Instrument Air Compressor 1C Temporarily Taken Out of Svc to Repair after- Cooler Leak.Water Leak Caused by Normal Wear of after- Cooler.Air Compressor Returned to Svc After Repairs ML20052A3331982-04-27027 April 1982 LER 81-044 Has Been Cancelled ML20050B2541982-03-19019 March 1982 LER 82-006/03L-0:on 820218,primary Coolant Moisture Exceeded Tech Specs.Caused by Contamination W/Moisture During Maint Outage.Reactor Shutdown & Coolant Purification Trains Utilized to Reduce Impurity Levels ML20042B8231982-03-17017 March 1982 LER 82-005/03L-0:on 820215,loop 2 Steam Generator Penetration Rupture Disk 1 Leak Alarm Pressure Switch Found Isolated.Caused by Closed Pressure Switch Isolation Valve.Valve Opened ML20041F5791982-03-0808 March 1982 LER 82-007/01T-0:on 820222,control Rod Pairs for Regions 7 & 28 Did Not Insert Automatically Following Manual Scram. Possibly Caused by Binding or Sticking of Control Rod Drive Mechanism.Control Rods Exercised to Eliminate Sticking ML20041C3231982-02-19019 February 1982 LER 82-002/03L-0:on 820121,during Surveillance Testing, W/Reactor Shut Down,Three Loss of Bearing Water Pressure Differential Switches Found W/Setpoints Less Conservative than Required.Caused by Instrument Drift.Switches Recalibr ML20041C2761982-02-19019 February 1982 LER 82-003/03L-0:on 820122,one Drain Malfunction Pressure Differential Switch on 1C Helium Circulator Found Less Conservative than Tech Specs.Caused by Dirty Contacts. Contacts Cleaned & Switch Recalibr ML20041A9891982-02-16016 February 1982 LER 82-004/01T-0:on 820202,inadvertent Radioactive Liquid Waste Release Occurred from Receiver a During Plant Shutdown for Design Mods to Circulator Auxiliary Sys.Caused by Improper Valve Lineup.Event Reviewed W/Operators ML20040G9511982-02-0505 February 1982 LER 82-001/03L-0:on 820108,18 Snubbers Found Inoperable During Surveillance Testing,Indicating Inoperability During Reactor Operation.Caused by Seal Leakage & Deficiencies in Piston Position & Oil Level.Snubbers Repaired ML20040B8081982-01-13013 January 1982 LER 81-074/03L-0:on 811214,cold Reheat Snubber CRS-219 Found Detached from Pipe Mounting,Rendering Snubber Operable.Caused by Failure of Cotter Pin,Allowing Eyebolt to Be Displaced Out of Pipe & Snubber Rod Mounting ML20040B7911982-01-12012 January 1982 LER 81-075/03L-0:on 811221,two Sample Flow Circuits Found Out of Calibr During Annual Calibr of Primary Coolant Moisture Scram Instrumentation.Caused by Change in Instrument Characteristics.Procedures Being Revised ML20039F4911982-01-0404 January 1982 LER 81-073/03L-0:on 811208,one Helium Circulator Bearing Drain Pressure Low Switch Found to Have Trip Point Outside Required Limits.Caused by Dirt Accumulation in Electrical Switch That Impeded Contact ML20039C6321981-12-17017 December 1981 LER 81-072/03L-0:on 811117,PCRV Rupture Disk M-11701 Setpoint Exceeded Tech Specs Limits.Caused by Belleville Washer Operating Point Drift.Disks Under Evaluation ML20011A6371981-10-22022 October 1981 LER 81-060/03L-0:between 810922-1013,emergency Feedwater to Loop 1 Helium Circulator Water Turbine Drives Was Isolated on Three Occasions.Caused by Leakage Between Seat Ring & Valve Body Pressure Control Valve ML20010H9131981-09-11011 September 1981 LER 81-052/03L-0:on 810812,standby Bearing Water Makeup Pump Removed from Svc.Caused by Need to Repair Bonnet Leak in Valve in Suction Line to Pump.Pump Returned to Svc After Repair Completed ML20010J0141981-09-11011 September 1981 LER 81-050/03L-0:on 810814,total Dissolved Solids in Plant Nonradioactive Liquid Waste Effluent for 810809 Was Discovered to Have Exceeded Tech Specs.Caused by Improper Circulating Water Blowdown Arrangement.Blowdown Adjusted ML20010H8821981-09-0404 September 1981 LER 81-048/03L-0:on 810808 & 25 Loop 1 Prestressed Concrete Reactor Vessel Cooling Water Outlet Temp Exceeded 120 F Due to Failure of Temp Controller.Caused by Cold Solder Joint & Failure of Transistor in Output Circuit,Respectively ML20010H9301981-09-0101 September 1981 LER 81-049/03L-0:during 810802-07,increase Occurred in Offgassing from Core & Core Outlet Temps.Caused by Increased Primary Coolant Moisture & Oxidants from Refueling Shutdown ML20010G2711981-08-26026 August 1981 LER 81-046/03L-0:on 810728,emergency Feedwater Supply to Loop 1 Helium Circular Water Turbines Isolated to Repair Leaking 2-inch Consolidated Safety Relief Valves.Caused by Valve Leakage Downstream of Pressure Control Valve ML20010G1691981-08-26026 August 1981 LER 81-045/03L-0:on 810727,during Normal Startup Operation, Primary Coolant Dewpoint Exceeded Tech Spec Limits.Caused by Contamination Due to Moisture.Contaminants Removed from Primary Coolant ML20010G3371981-08-20020 August 1981 LER 81-051/03L-0:on 810721,Class I Snubbers Removed from Svc for Structural Mods W/Plant Operating at Power.Caused by Seismic Restraint Analysis Program.Snubbers Returned to Svc Following Mods ML20010G3181981-08-14014 August 1981 LER 81-043/03L-0:on 810717 & 0807,reactor Operated at Power W/One Class I Snubber Inoperable.Caused by Empty Oil Reservoirs on BFS-398E & MSS-149 Due to Leaking Fitting on Valve Block & Leaking Piston Seal.Fitting Tightened ML20010A1601981-07-16016 July 1981 LER 81-041/03L-0:on 810616,control Room Exhaust Damper Failed to Close.Caused by Dust Accumulation on Damper Vanes. Damper Operated Properly When Retested.Preventive Maint Program to Be Developed to Inspect & Clean Vanes ML20009E5101981-07-0202 July 1981 LER 81-039/03L-0:on 810602,following Routine Chlorination of Circulating Water Sys,Sample Indicated Excessive Residual Chlorine in Plant Liquid Effluent.Cause Unknown.Subsequent Chlorinations Showed No Abnormalities ML20009E5581981-07-0202 July 1981 LER 81-040/03L-0:between 810604 & 09,eight Hydraulic Shock Suppressors Were Found Out of Oil.Caused by Empty Hydraulic Oil Reservoirs Due to Leaking Seals & O-rings in Snubbers. Reservoirs Cleaned.Seals & O-rings Replaced ML20009E7191981-06-18018 June 1981 Revised LER 81-008/03X-1:on 810120,during Shutdown Maint & Primary Coolant Pressure Scram Calibr,Voltage Outputs of Pressure Transmitter Discovered High.Caused by Instrument Drift.Transmitter Calibr.Surveillance Test Completed ML20009E7011981-06-10010 June 1981 LER 81-035/03L-0:on 810511,w/plant at 70% Thermal Power During a Diesel Generator Set Surveillance Test,B Engine Tripped & Declutched.Caused by Failed Exhaust Temp Switch. Switch Repaired.Test Completed.Generator Returned to Svc ML20009A5501981-06-0505 June 1981 LER 81-038/03L-0:on 810507,two Class I Hydraulic Shock Suppressors Removed from Svc.Caused by Decision to Modify Suppressors to Original Configuration W/Zero Bleed Rate Block Valves ML20009A5341981-06-0303 June 1981 LER 81-034/03L-0:on 810504,equipment Necessary to Terminate Release from Liquid Waste Sys & Reactor Sump Found Not Operating Properly.Caused by Plugged Sense Lines on Flow Element Associated W/Control Valve ML20009A5281981-05-28028 May 1981 LER 81-032/03L-0:on 810428,hot Reheat Snubber HRS-244 Found Inoperable.Caused by Empty Hydraulic Oil Reservoir Due to Leaking Elbow Fitting.Fitting Tightened,Reservoir Refilled & Snubber Returned to Svc ML20004D5781981-05-27027 May 1981 LER 81-036/01T-0:on 810512,liquid Waste Discharge Exceeded Specified Limit for Tritium Concentration.Caused by Design Deficiency.Downstream of Valve HV 6212,150-200 Gallon Dead Leg Released Regardless of Dilution Flow Adequacy ML20004D7171981-05-27027 May 1981 LER 81-031/03L-0:on 810427,during Normal Surveillance Testing,Diesel Engine B Tripped & Declutched on Starting. Caused by Load Imbalance Between Engines a & B Due to Normal Wear of Linkage.Linkage Was Adjusted ML20004D6661981-05-27027 May 1981 LER 81-033/03L-0:on 810427,helium Circulator 1C Speed/Wobble Modifier Malfunctioned Causing Loss of Plant Protective Sys Functions to High Speed Trip Circuits.Caused by Electronic Circuit Unbalance.Spare Speed Element Installed 1993-06-03
[Table view] Category:RO)
MONTHYEARML20045A4291993-06-0303 June 1993 LER 93-003-00:on 930505,new Source of Natural Gas Introduced within 0.5 Miles of ISFSI & Reactor Bldg W/O Prior NRC Approval.Caused by Field Routing of Natural Gas Pipe.Well Isolated by Well operator.W/930603 Ltr ML20043E0991990-05-31031 May 1990 LER 89-018-01:on 890827,cracking Found in Incoloy Alloy 800 Main Steam Ringheaders & Condition Determined to Have Generic Implications.Caused by Creep Failure.Main Steam Ringheaders repaired.W/900531 Ltr ML20042G4211990-05-10010 May 1990 LER 90-001-00:on 900410,non-essential Bus 5,4160/480-volt Transformer N-9215 Experienced Fault.Caused by Breakdown of Insulation on Secondary Coils of Transformer.Coils of Transformer rewound.W/900510 Ltr ML20011D4641989-12-20020 December 1989 LER 89-014-01:on 890818,four Fire Barrier Penetration Seals in Bldg 10 Did Not Meet Foam Seal Structure Criteria of Seal Spec.Caused by Improper Curing During Installation.Fire Watch Established & Seals repaired.W/891220 Ltr ML20024E0021983-07-29029 July 1983 LER 83-023/03L-0:on 830701 & 02,emergency Feedwater Unavailable to Drive Loop I Helium Circulation Water Turbines.Caused by Normal Wear of Valve PV-21243.Valve Internals Replaced & Valve calibr.W/830729 Ltr ML20024B9861983-07-0101 July 1983 LER 83-020/03L-0:on 830604,emergency Feedwater Header Supply to Loop I Helium Circulator Turbine Water Drive Isolated & Bearing Water Make Up Pump Taken Out of Svc.Caused by Flexitallic Gasket Failure Due to Normal wear.W/830701 Ltr ML20024A8521983-06-22022 June 1983 Updated LER 80-041/03X-2:on 800724,one of 12 Helium Circulator Seal Malfunction Pressure Differential Switches Discovered W/Trip Point Outside Tech Spec Limits.Caused by Dirt Accumulation in Electrical switches.W/830622 Ltr ML20023D9021983-05-26026 May 1983 LER 83-017/01T-0:on 830512,insp Performed Per IE Bulletin 83-03 Identified Six of Eight Check Valves Frozen in mid- Position.Caused by Corrosion & Rusting Valve Internal Parts. Valves Cleaned & Internal Components Replaced ML20028G2831983-01-28028 January 1983 LER 82-053/03L-0:on 821229,fuel Storage Well Pressure Exceeded Atmospheric Pressure While Reactor Was Shut Down. Caused by One Gas Compressor Being Out of Svc for Maint and Other Pumping Less than Capacity.Compressors Repaired ML20028G2711983-01-28028 January 1983 LER 82-054/03L-0:on 821229,outlet Temps Exceeded 120 F Limit When Reactor Became Critical During Isolation of Svc Water Flow to Pcrv Cooling Water Hx.Caused by Lack of Cooling Source.Design Change Initiated ML20028F2401983-01-19019 January 1983 LER 82-051/03L-0:on 821220,during Surveillance Test,One of Six Steam Pipe Rupture & One of 12 Steam Pipe Rupture Channels Identified Inoperable Due to Low Response to Calibr Noise.Caused by Failure of Resistor ML20028F2881983-01-17017 January 1983 LER 83-001/01T-0:on 830101 & 02,reactor Operated W/O Min Number of Operable Moisture Monitor Channels Required Per Table 4.4.1 of Limiting Conditions for Operation.Caused by Personnel Misinterpretation of Tech Specs ML20028A3101982-11-10010 November 1982 LER 82-042/03L-0:on 821013,unplanned Radioactive Gas Release Occurred W/Reactor Shutdown & Depressurized.Caused by High Airborne Activity in Reactor Bldg Due to Leaking Blank Flange.Emergency Procedures Initiated.Flange Repaired ML20028A2861982-11-10010 November 1982 LER 82-041/03L-0:on 821011,during Calibr of Radioactive Liquid Effluent Monitors,Trip Point for RIS-6212 Found to Be Less Conservative than Required.Caused by Instrument Drift. High Voltage & Discriminator Settings Adjusted ML20023A7451982-10-0808 October 1982 LER 82-036/03L-0:on 820908,one of Two Bearing Water Makeup Pumps Removed from Svc.Caused by Need to Rebuild Mechanical Seal Due to Normal Wear.Seal Rebuilt ML20052H9881982-05-12012 May 1982 LER 82-011/03L-0:during 820412-20,plant Operated in Degraded Mode of Limiting Conditions for Operation 4.2.11 Three Times & 4.2.10 Once.Caused by Offgas of Moisture from Core as Plant Returned to Power from Maint Outage ML20052H8751982-05-12012 May 1982 LER 82-013/03L-0:on 820412,separation in Axial Positions of Two Partially Inserted Control Rod Groups Fell Slightly Below Limit of 10 Ft.Cause Not Stated.Control Rods Repositioned ML20052G4151982-05-10010 May 1982 LER 82-012/03L-0:on 820410,at 10% Power,Instrument Air Compressor 1C Temporarily Taken Out of Svc to Repair after- Cooler Leak.Water Leak Caused by Normal Wear of after- Cooler.Air Compressor Returned to Svc After Repairs ML20052A3331982-04-27027 April 1982 LER 81-044 Has Been Cancelled ML20050B2541982-03-19019 March 1982 LER 82-006/03L-0:on 820218,primary Coolant Moisture Exceeded Tech Specs.Caused by Contamination W/Moisture During Maint Outage.Reactor Shutdown & Coolant Purification Trains Utilized to Reduce Impurity Levels ML20042B8231982-03-17017 March 1982 LER 82-005/03L-0:on 820215,loop 2 Steam Generator Penetration Rupture Disk 1 Leak Alarm Pressure Switch Found Isolated.Caused by Closed Pressure Switch Isolation Valve.Valve Opened ML20041F5791982-03-0808 March 1982 LER 82-007/01T-0:on 820222,control Rod Pairs for Regions 7 & 28 Did Not Insert Automatically Following Manual Scram. Possibly Caused by Binding or Sticking of Control Rod Drive Mechanism.Control Rods Exercised to Eliminate Sticking ML20041C3231982-02-19019 February 1982 LER 82-002/03L-0:on 820121,during Surveillance Testing, W/Reactor Shut Down,Three Loss of Bearing Water Pressure Differential Switches Found W/Setpoints Less Conservative than Required.Caused by Instrument Drift.Switches Recalibr ML20041C2761982-02-19019 February 1982 LER 82-003/03L-0:on 820122,one Drain Malfunction Pressure Differential Switch on 1C Helium Circulator Found Less Conservative than Tech Specs.Caused by Dirty Contacts. Contacts Cleaned & Switch Recalibr ML20041A9891982-02-16016 February 1982 LER 82-004/01T-0:on 820202,inadvertent Radioactive Liquid Waste Release Occurred from Receiver a During Plant Shutdown for Design Mods to Circulator Auxiliary Sys.Caused by Improper Valve Lineup.Event Reviewed W/Operators ML20040G9511982-02-0505 February 1982 LER 82-001/03L-0:on 820108,18 Snubbers Found Inoperable During Surveillance Testing,Indicating Inoperability During Reactor Operation.Caused by Seal Leakage & Deficiencies in Piston Position & Oil Level.Snubbers Repaired ML20040B8081982-01-13013 January 1982 LER 81-074/03L-0:on 811214,cold Reheat Snubber CRS-219 Found Detached from Pipe Mounting,Rendering Snubber Operable.Caused by Failure of Cotter Pin,Allowing Eyebolt to Be Displaced Out of Pipe & Snubber Rod Mounting ML20040B7911982-01-12012 January 1982 LER 81-075/03L-0:on 811221,two Sample Flow Circuits Found Out of Calibr During Annual Calibr of Primary Coolant Moisture Scram Instrumentation.Caused by Change in Instrument Characteristics.Procedures Being Revised ML20039F4911982-01-0404 January 1982 LER 81-073/03L-0:on 811208,one Helium Circulator Bearing Drain Pressure Low Switch Found to Have Trip Point Outside Required Limits.Caused by Dirt Accumulation in Electrical Switch That Impeded Contact ML20039C6321981-12-17017 December 1981 LER 81-072/03L-0:on 811117,PCRV Rupture Disk M-11701 Setpoint Exceeded Tech Specs Limits.Caused by Belleville Washer Operating Point Drift.Disks Under Evaluation ML20011A6371981-10-22022 October 1981 LER 81-060/03L-0:between 810922-1013,emergency Feedwater to Loop 1 Helium Circulator Water Turbine Drives Was Isolated on Three Occasions.Caused by Leakage Between Seat Ring & Valve Body Pressure Control Valve ML20010H9131981-09-11011 September 1981 LER 81-052/03L-0:on 810812,standby Bearing Water Makeup Pump Removed from Svc.Caused by Need to Repair Bonnet Leak in Valve in Suction Line to Pump.Pump Returned to Svc After Repair Completed ML20010J0141981-09-11011 September 1981 LER 81-050/03L-0:on 810814,total Dissolved Solids in Plant Nonradioactive Liquid Waste Effluent for 810809 Was Discovered to Have Exceeded Tech Specs.Caused by Improper Circulating Water Blowdown Arrangement.Blowdown Adjusted ML20010H8821981-09-0404 September 1981 LER 81-048/03L-0:on 810808 & 25 Loop 1 Prestressed Concrete Reactor Vessel Cooling Water Outlet Temp Exceeded 120 F Due to Failure of Temp Controller.Caused by Cold Solder Joint & Failure of Transistor in Output Circuit,Respectively ML20010H9301981-09-0101 September 1981 LER 81-049/03L-0:during 810802-07,increase Occurred in Offgassing from Core & Core Outlet Temps.Caused by Increased Primary Coolant Moisture & Oxidants from Refueling Shutdown ML20010G2711981-08-26026 August 1981 LER 81-046/03L-0:on 810728,emergency Feedwater Supply to Loop 1 Helium Circular Water Turbines Isolated to Repair Leaking 2-inch Consolidated Safety Relief Valves.Caused by Valve Leakage Downstream of Pressure Control Valve ML20010G1691981-08-26026 August 1981 LER 81-045/03L-0:on 810727,during Normal Startup Operation, Primary Coolant Dewpoint Exceeded Tech Spec Limits.Caused by Contamination Due to Moisture.Contaminants Removed from Primary Coolant ML20010G3371981-08-20020 August 1981 LER 81-051/03L-0:on 810721,Class I Snubbers Removed from Svc for Structural Mods W/Plant Operating at Power.Caused by Seismic Restraint Analysis Program.Snubbers Returned to Svc Following Mods ML20010G3181981-08-14014 August 1981 LER 81-043/03L-0:on 810717 & 0807,reactor Operated at Power W/One Class I Snubber Inoperable.Caused by Empty Oil Reservoirs on BFS-398E & MSS-149 Due to Leaking Fitting on Valve Block & Leaking Piston Seal.Fitting Tightened ML20010A1601981-07-16016 July 1981 LER 81-041/03L-0:on 810616,control Room Exhaust Damper Failed to Close.Caused by Dust Accumulation on Damper Vanes. Damper Operated Properly When Retested.Preventive Maint Program to Be Developed to Inspect & Clean Vanes ML20009E5101981-07-0202 July 1981 LER 81-039/03L-0:on 810602,following Routine Chlorination of Circulating Water Sys,Sample Indicated Excessive Residual Chlorine in Plant Liquid Effluent.Cause Unknown.Subsequent Chlorinations Showed No Abnormalities ML20009E5581981-07-0202 July 1981 LER 81-040/03L-0:between 810604 & 09,eight Hydraulic Shock Suppressors Were Found Out of Oil.Caused by Empty Hydraulic Oil Reservoirs Due to Leaking Seals & O-rings in Snubbers. Reservoirs Cleaned.Seals & O-rings Replaced ML20009E7191981-06-18018 June 1981 Revised LER 81-008/03X-1:on 810120,during Shutdown Maint & Primary Coolant Pressure Scram Calibr,Voltage Outputs of Pressure Transmitter Discovered High.Caused by Instrument Drift.Transmitter Calibr.Surveillance Test Completed ML20009E7011981-06-10010 June 1981 LER 81-035/03L-0:on 810511,w/plant at 70% Thermal Power During a Diesel Generator Set Surveillance Test,B Engine Tripped & Declutched.Caused by Failed Exhaust Temp Switch. Switch Repaired.Test Completed.Generator Returned to Svc ML20009A5501981-06-0505 June 1981 LER 81-038/03L-0:on 810507,two Class I Hydraulic Shock Suppressors Removed from Svc.Caused by Decision to Modify Suppressors to Original Configuration W/Zero Bleed Rate Block Valves ML20009A5341981-06-0303 June 1981 LER 81-034/03L-0:on 810504,equipment Necessary to Terminate Release from Liquid Waste Sys & Reactor Sump Found Not Operating Properly.Caused by Plugged Sense Lines on Flow Element Associated W/Control Valve ML20009A5281981-05-28028 May 1981 LER 81-032/03L-0:on 810428,hot Reheat Snubber HRS-244 Found Inoperable.Caused by Empty Hydraulic Oil Reservoir Due to Leaking Elbow Fitting.Fitting Tightened,Reservoir Refilled & Snubber Returned to Svc ML20004D5781981-05-27027 May 1981 LER 81-036/01T-0:on 810512,liquid Waste Discharge Exceeded Specified Limit for Tritium Concentration.Caused by Design Deficiency.Downstream of Valve HV 6212,150-200 Gallon Dead Leg Released Regardless of Dilution Flow Adequacy ML20004D7171981-05-27027 May 1981 LER 81-031/03L-0:on 810427,during Normal Surveillance Testing,Diesel Engine B Tripped & Declutched on Starting. Caused by Load Imbalance Between Engines a & B Due to Normal Wear of Linkage.Linkage Was Adjusted ML20004D6661981-05-27027 May 1981 LER 81-033/03L-0:on 810427,helium Circulator 1C Speed/Wobble Modifier Malfunctioned Causing Loss of Plant Protective Sys Functions to High Speed Trip Circuits.Caused by Electronic Circuit Unbalance.Spare Speed Element Installed 1993-06-03
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20196G6731997-07-0101 July 1997 Informs Commission That Decommissioning Process Has Been Completed at PSC of Colorado Fsvngs,Unit 1 Located in Town of Platteville in Weld County,Co ML20141K9961997-05-0505 May 1997 Safety Evaluation Supporting Amend 89 to License DPR-34 ML20140E1121997-04-10010 April 1997 Confirmatory Survey of Group Effluent Discharge Pathway Areas for Fsv Nuclear Station,Platteville,Co ML20134D1661997-01-30030 January 1997 Rev 1,Vol 6 to Final Survey Rept,Final Survey of Group E (Book 2A of 2) ML20137S6111996-12-31031 December 1996 Annual Rept Pursuant to Section 13 or 15(d) of Securities Exchange Act 1934, for Fy Ended Dec 1996 ML20134G6401996-10-29029 October 1996 Rev 0,Volume 6,Books 1 & 2 of 2 to Final Survey of Group E ML20134G6171996-10-29029 October 1996 Rev 2,Volume 1,Books 1 & 2 of 2 to Final Survey Description & Results ML20134G7271996-10-29029 October 1996 Rev 0,Volume 11,Book 1 of 1 to Final Survey of Group J ML20134G6861996-10-29029 October 1996 Rev 0,Volume 8,Books 1 & 2 of 2 to, Final Survey of Group G ML20134G6321996-10-26026 October 1996 Rev 1,Volume 5,Books 2 & 3 of 3 to Final Survey of Group D ML20133D7831996-10-22022 October 1996 Preliminary Rept - Orise Support of NRC License Insp at Fsv on 960930-1003 ML20116A4661996-07-19019 July 1996 Fsv Final Survey Exposure Rate Measurements ML20112J6861996-05-31031 May 1996 June 1996 Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments for Fsv Decommissioning.Rept Covers Period of 960216-0531 ML20112C1531996-05-17017 May 1996 Fsv Final Survey Exposure Rate Measurements ML20101G5521996-03-21021 March 1996 Confirmatory Survey Activities for Fsv Nuclear Station PSC Platteville,Co, Final Rept ML20097E3201996-01-31031 January 1996 Nonproprietary Fort St Vrain Technical Basis Documents for Piping Survey Instrumentation ML20095K4131995-12-26026 December 1995 Rev 3 to Decommissioning Plan ML20095H7211995-12-20020 December 1995 Revs to Fort St Vrain Decommissioning Fire Protection Plan Update ML20095K9751995-12-15015 December 1995 Fort St Vrain Project Update Presentation to NRC, on 951207 & 15 ML20096C1671995-12-13013 December 1995 Rev 4 to Decommissioning Fire Protection Plan ML20094M1651995-11-30030 November 1995 Nonproprietary Fsv Technical Basis Documents for Piping Survey Implementation ML20092F3461995-09-14014 September 1995 Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments for Fsv Decommissioning, Covering Period of 950516-0815.W/ ML20137H3531994-12-31031 December 1994 Partially Withheld, Rept of Independent Counsel Investigation Concerning Issues at Fort St Vrain Nuclear Generating Station Decommissioning Project, App D,Comments by Mkf & Westinghouse Team & Responses ML20137S2331994-12-31031 December 1994 Rept of Independent Counsel Investigation Concerning Issues at Fort St Vrain Nuclear Generating Station Decommissioning Project, Dec 1994 ML20029C6031993-12-31031 December 1993 1993 Annual Rept Public Svc Co of Colorado. W/940405 Ltr ML20058Q3791993-12-21021 December 1993 Rev 1 to Decommissioning Plan for Fort St Vrain Nuclear Generating Station ML20045B3641993-06-30030 June 1993 June 1993 Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments for Fsv Decommissioning. ML20045A4291993-06-0303 June 1993 LER 93-003-00:on 930505,new Source of Natural Gas Introduced within 0.5 Miles of ISFSI & Reactor Bldg W/O Prior NRC Approval.Caused by Field Routing of Natural Gas Pipe.Well Isolated by Well operator.W/930603 Ltr ML20077D1631993-05-10010 May 1993 Enforcement Conference, in Arlington,Tx ML20125C7161992-12-0707 December 1992 Part 21 Rept Re Possibility for Malfunction of Declutching Mechanisms in SMB/SB-000 & SMB/SB/SBD-00 Actuators. Malfunction Only Occurs During Seismic Event.Balanced Levers May Be Purchased from Vendor.List of Affected Utils Encl ML20128D7191992-12-0101 December 1992 Safety Evaluation Approving Exemption from Requirement of 10CFR50.54(q) to Change to Biennial Emergency Plan Exercise Rather than Annual Following Completion of Next Scheduled Exercise at Plant ML20127P5861992-11-23023 November 1992 Followup to 921005 Part 21 Rept Re Potential Defect in SB/SBD-1 Housing Cover Screws.Procedure Re Replacement of SBD-1 Spring Cover Bolts Encl.All Fasteners Should Be Loosened & Removed.List of Affected Utils Encl ML20127F5691992-11-0303 November 1992 Informs Commission of Intent to Issue Order Approving Plant Decommissioning Plan & Corresponding Amend to License DPR-34 ML20101E5761992-05-31031 May 1992 Monthly Defueling Operations Rept for May 1992 for Fort St Vrain ML20096E8221992-04-30030 April 1992 Monthly Operating Rept for Apr 1992 for Fort St Vrain.W/ ML20095E9601992-04-17017 April 1992 Rev to Fort St Vrain Proposed Decommissioning Plan ML20100R7431992-03-31031 March 1992 Monthly Operating Rept for Mar 1992 for Fort St Vrain.W/ ML20090L0621992-02-29029 February 1992 Monthly Operating Rept for Feb 1992 for Fort St Vrain Unit 1 ML20092D0081992-01-31031 January 1992 Monthly Operating Rept for Jan 1992 for Fort St Vrain Nuclear Generating Station ML20102B2241992-01-22022 January 1992 Fort St Vrain Station Annual Rept of Changes,Tests & Experiments Not Requiring Prior Commission Approval Per 10CFR50.59, for Period 910123-920122 ML20094N6701991-12-31031 December 1991 Public Svc Co Annual Financial Rept for 1991 ML20091J6251991-12-31031 December 1991 Monthly Operating Rept for Dec 1991 for Fort St Vrain.W/ ML20094D6711991-11-30030 November 1991 Monthly Operating Rept for Nov 1991 for Fort St Vrain Unit 1 ML20090M1871991-11-20020 November 1991 FOSAVEX-91 Scenario for 1991 Plant Exercise of Defueling Emergency Response Plan ML20086D6891991-11-15015 November 1991 Proposed Decommissioning Plan for Fort St Vrain Nuclear Generating Station ML20085N1451991-11-0505 November 1991 Revised Ro:Operability Date of 910830 for Electric Motor Driven Fire Water Pump P-4501 Not Met.Pump Not Actually Declared Operable Until 911025.Caused by Unforseen Matl & Testing Problems.Equivalent Pump Available ML20086C5451991-10-31031 October 1991 Monthly Operating Rept for Oct 1991 for Fort St Vrain.W/ ML20085H6611991-10-10010 October 1991 Assessment of Mgt Modes for Graphite from Reactor Decommissioning ML20091D7671991-10-0101 October 1991 Rev B to Engineering Evaluation of Prestressed Concrete Reactor Vessel & Core Support Floor Structures for Proposed Sys 46 Temp Change ML20085D9861991-09-30030 September 1991 Monthly Operating Rept for Sept 1991 for Fort St Vrain.W/ 1997-07-01
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NRC FORM 3G6 U. S. NUCLEArt nEGULATORY COMMISSIOld (7 77) .
LICENSEE EVENT REPORT CONT *iOL BLOCK: l l l l l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 1 f
O o 1 C 0 F SlV 1 @l0l0 -
0 0 0 0 0 l- l0 0 @l4 1LICENSE 25 26 l1 l 2 0 @l TYPE 30 l@
57 C A T 58 7 8 9 . CENSEE CODE 14 15 uCENsE NUVBER CON'T 0 1 "E[p"C o l60L l@l610 l 5 l 0COCKET l 0 l NUM8 0 l ER 2 l 6 l 768l@l631 l 2 EVENT l 1 DATE 1 l 7 l 874 l@l75 01 REPORT 2 l ll CATE 21 7 l o80 @
7 3 VENT DESCRIPTION AND PROB ABLE CONSEQUENCES h a 2
' Operations persennel observed that malfuncticrns in lA. 1C. and 1D circulator speed I o 3i l measurement caused loss of circulator high speed signals. Problems occurred at I Reportable oer o 4 l different dates. All circulators not affected at the same time. 1 o 3 ] Technical Specification AC 7.5.2(b)2, operation under a degraded mode permitted by I o 6 lLCO 4.4.1. No ef fect on plant operation. Probable consequence was loss of high l ol7 l speed Circulator trip function. No af fect on public health or safety. Redundant l o aj l system available and operable for each circulator. 30 7 8 3 SYSTEM CAUSE CAUSE COMP. VA LV E CODE CODE SUSCCOE COVPONENT CCDE SU8 CODE SU8 CODE o 9 lI lB @ El@ El @ lI N lS lT lR lU l@ l Tl@ 20 Z @
7 8 9 10 11 12 13 18 19
_ SEQUENTI AL OCCURRENCE PEPCRT REVISICN LER RO EV ENT YE AR REPORT NO. CODE TYPE N O.
@ 4EP g l-l l0 l0 l 5 l l/l 10 l3 l lXl l-l l2 l s
_ l217 22l8 l 23 24 '6 27 28 23 30 31 32 ACTION FUTURE EFFECT SH UT DC'AN ATTACHVENT NPRC-4 PRlYE CCMP. CCMPCNENT TAKEN ACTICN ON PLANT YETHOD HOURS 44 SUBYiTTED FORU dub, SUPPLIER MANUFACTURER IXl@lXl@
_ lZl@ l36Z l@ l0 l0 l0 l0 3/
l Yl@ lN l@ Nl@ l44C l 219 l047l@
J3 34 3d 40 di 42 43 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i o l General Atomic circulator speed / wobble modifiers caused a loss of clant orotective i l sys tem functions to high speed trio circuits due to electronic circuit unbalance l
, 7 l caused by signal cable resistance change. Modifiers adjusted, soare cable connected 1 3 3 las applicable. Adjustment of speed modifiers being checked weekly. Problem under l i .2 l investigation. l 3 3 30
$A % SCV.ER OTHER STATUS IS O RY DISCOVERY DESCRIPTION t 5 E l@ l0 l 5 l 0 l@ N/A l l A l@l Operator Observation l ACTIVITY CONTENT nELEASED OF RELEASE AMOUNT OF ACTIVITY LCCATION O': RELEASE 1 6 lZ l lZ N/A l l N/A l 7 a 9 10 11 44 45 SJ PERSONNEL EXPOSURES NUYBE R TYPE DESCRIPTICN i 7 10 10 10 l@lz l@l N/A i 3 9 11 12 13 30 PERSONNEL INJURIES NUV3ER CESCRIPTION i a LOJoi0181 N/A I d 9 11 12 80 L JSS OF CR O AVAGE TO FACILITY Q fYPE DESCRIPTION v i
9" \Z '
l@l N/A "
ISSUED Pueuav D
79022200 0 NRC UsE ONLY o 2
o lN lhl ESCRIPTICN N/A l ll ll l ll l l l l l lj 7 3 0 10 68 63 30 ;
w..eccPaeoAnen M b J. W. Gahm ,, 3y (303) 785-2253 2
REPORT DATE: Feb ruary 12, 1979 REPORTABLE OCCURRENCE 78-05 ISSUE 2 OCCURRENCE DATE: December ll,19 78 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO P. O. BOX 361 PLATTEVILLE, COLORADO 80651 REPORT No. 50- 26 7/ 78-05/03-X- 2 Supplemental Report: Additional Information IDENTIFICATION OF OCCURRENCE:
On twelve occasions between December 11, 1978, and February 1, 19 79, malf unc-tions of helium circulator speed modifiers caused loss of Plant Protective System function of high speed trips. Each of the twelve malfunctions resulted in operation under a degraded mode permitted by LCO 4.4.1 and are reparteble per Fo rt S t. Vrain Technical Specification AC 7.5.2(b)2.
This repcrt is sLbmitted as a supplement to Reportable Occurrence Report No.
50-267/ 78-05/03-L-0, Preliminary, ta provide additional information on the problems experienced since Mcvember 19, 1978.
EVENT DESCRIPTION:
Event 1 - Soeed Modifier, S5F21161 On December 11, 1978, while operating at 50% thermal power and 150 MW electrical power, operations personnel observed that one of three chan-nels for the LA circulator speed protection tripped on low speed while the circulator was operating at approximately 5,900 rpm. This resulted in loss of the speed signal and trip capability in one of the three as-sociated high speed t rip channels for the LA circulator. Two redundant channels were available and operable.
Event 2 - Speed Modiff er, S>b21161 On December 12, 1978, while operating at 69% thermal power and 210 MW electrical power, operations personnel observed that one of three chan-nels for the 1A circulator speed protection tripped on low speed while the circulator was operating at approxima tely 7,000 rpm. This resulted in loss of the speed signal and trip capability in one o f the three as-sociated high speed trip channels for the LA circulator. Two redundant channels were available and operable.
Event 3 - Speed Modifier, S5921161 on December 29, 1978, while operating at 64% thermal power and 200 MW electrical power, operations personnel observed that one of three chan-nels for the 1A circulator speed protection tripped on low speed while
REPORTABLE OCCURRENCE 78-05 ISSUE 2 Page 2 of 4 EVENT DESCRIPTION (continued):
Event 3 - Speed Modifier, SM-21161 (continued) the circulator was operating at approximately 6,800 rpm. This resulted in loss of the speed signal and trip capability in one of the three as-sociated high speed trip channels for the lA circulator. Two redundant channels were available and operable.
Event 4 - Soeed Modifier, SM-21161 On January 1,1979, while operating at 64% thermal power and 200 MW electrical power, operations personnel observed that one of three chan-nels for the 1A circulator speed protection tripped on low speed while the circulator was operating at approximately 6,800 rpm. This resulted in loss of the speed signal and trip capability in one of the three as-sociated high speed trip ' channels for the 1A circulator. Two redundant channels were available and operable.
Event 5 - Speed Modifier, Sdb21162 On January 22, 1979, while operating at 28% thermal power and zero elec-trical power, operations personnel observed that one of three channels for the 1C circulator speed protection tripped on low speed while the circulator was operating at approximately 4,500 rpm. This resulted in loss of the speed signal and trip capability in one o f the three asso-ciated high speed trip channels for the 1C circulator. Two redundant channels were available and operable.
Event 6 - Soeed >bdifier, S$921162 On January 23, 1979, while operating at 60% thermal power and 185 MW electrical power, operations personnel observed that one of three chan-nels for the 1C circulator speed protection tripped on low speed while the circulator was operating at approximately 6,000 rpm. This resulted in loss of the speed signal and trip capability in one of the three as-sociated high speed trip channels for the 1C circulator. Two redundant channels were available and operable.
Event 7 - Soeed Modifier, S}b21172 On January 23, 1979, while operating at 33% thermal power and 80 MW electrical power, operations personnel observed that one of three chan-nels for the 1D circulator speed protection tripped on low speed while the circulator was operating at approximately 4,600 rpm. This resulted in loss of the speed signal and trip capability in one of the three as-sociated high speed trip channels for the ID circulator. Two redundant channels were available and operable.
REPORTABLE OCCURRENCE 78-05 ISSUE 2 Page 3 of 4 EVENT DESCRIPTION (continued):
Events 8, 9, and 10 - Soeed Modifier, SM-21172 On January 28, 1977, while operating at 42% thermal power and 125 MW electrical power, operations personnel observed that one of three chan-nels for the 1D circulator speed protection tripped on low speed while the circulator was operating at approximately 5,200 rpm. These indivi-dual failures were experienced on the same channel. Each resulted in loss o f the speed signal and trip capability in one of the three asso-ciated high speed trip channels for the 1D circulator. The first failure occurred at approximately 0730 hours0.00845 days <br />0.203 hours <br />0.00121 weeks <br />2.77765e-4 months <br /> and was repaired at 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br />.
The second failure occurred at 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> and was repaired at 1630 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20215e-4 months <br />.
The third failure occurred at 1640 hours0.019 days <br />0.456 hours <br />0.00271 weeks <br />6.2402e-4 months <br /> and was repaired at 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br />.
In each of the three cases, two redundant channels were available and o p e rab le .
Event 11 - Soeed Modifier, S}h21172 On January 30, 1979, while operating at 42% thermal power and 125 MM electrical power, operations personnel observed that one o f three chan-nels for the ID circulator speed protection tripped on low speed while the circulator was operating at approximately 5,200 rpm. This resulted in loss of the speed signal and trip capability in one of the three as-sociated high speed trip channels for the 1D circulator. Two redundant channels were available and operable.
Event 12 - Speed Modifier, SM-21172 On Feb ruary 1,1979, while operating at 28% thermal power and 44 MW electrical power, operations personnel observed that one of three chan-nels for the 1D circulator speed protection tripped on low speed while the circulator was operating at approximately 4,500 rpm. This resulted in loss of the speed signal and trip capability in one o f the three as-sociated high speed trip channels for the 1D circulator. Two redundant channels were available and operable.
CAUS E DES CRIPTION :
Instrument calibration drif t due to bridge unbalance.
The balancing problem is caused by a change in resistance between the two leads of the speed element and ground at the circulator connection end. The difference in resistance occurs over a period of time in the cable connectors as a result of the te=perature and humidity of the ambient air.
CO RRECTIVE ACTION:
Events 1 and 2 Adjusting the 1A circulator speed modifier restored overspeed protec tion to the affected enannel.
.~
REPORTABLE OCCURRENCE 78-05 ISSUE 2 Page 4 of 4 CORRECTIVE ACTION (continued):
Events 3 and 4 Replacing the input cable with a spare and adjusting the 1A circulator speed modifier restored overspeed protection to the affected channel.
Event 5 No adjustments were made. Change in temperature from reactor power change altered cable tasistance and restored previous conditions of bridge balance and overspeed protection to the affected channel.
Event 6 Adjusting the 1C c _rculator speed modifier restored overspeed protection to the affected channel.
Events 7, 8, 9, 10, 11, and 12 Adjusting the 1D circulator speed modifier restored overspeed protection to the affected channel.
As an interim measure, the adjustment of the speed modifiers is being checked on a weekly basis.
The problem is under investigation to determine what can be done to correct this situa tion. The results will be reported in a future supplemental report.
Prepared by: Ld_ L ' , -
MicPylel J. Ferris V Technical Services Engineer Reviewed by: j,Z d
//W.Gahm f'echnicalServicesSupervisor Reviewed by: / d4 d Frank M. Mathie Operations Manager Approved by: Y Don 'Jarembourg Manager, Nuclear Produ[ction