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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20029D0371994-04-26026 April 1994 LER 94-004-00:on 940324,found Five Slow Rods While Scram Time Testing Was Being Performed.Caused by Contamination of Internal Scram Solenoid Pilot Valve Head Assemblies. Corrective Action:Install New Head assemblies.W/940426 Ltr ML20046C3991993-08-0606 August 1993 LER 92-009-01:on 920509,observed That Some of Fuel Rod Compression Springs Compressed More than Expected for Assembly Exposure Achieved.Max Envelope Size of Lower Tie Plate Will Be reduced.W/930806 Ltr ML20045G7911993-07-0808 July 1993 LER 93-005-00:on 930608,indicated That Response Time Test for RCIC Low Steam Pressure Isolation Instrumentation Invalid.Caused by Inappropriate Test Method.Procedures Governing Method of Testing Will Be revised.W/930708 Ltr ML20045E9601993-06-30030 June 1993 LER 92-017-02:on 920804,reactor Scrammed Due to Low Primary Water Tank Level Signal.Implemented Minor Change Package Which Will Install DC to DC Converter Between 24 Volt DC Power Supply & Pw Tank Level transmitters.W/930630 Ltr ML20045C5261993-06-16016 June 1993 LER 93-004-00:on 930517,inboard Containment Isolation Valve Which Supplies Steam to RCIC Sys Automatically Isolated Due to Topaz Inverter Failure.Calibr Instructions & PM Program Will Be reviewed.W/930616 Ltr ML20045A0151993-05-28028 May 1993 LER 92-011-02:on 920608,determined That Design Inadequacies Could Result in Exceeding 10CFR100 Limits.Caused by Failure of Original Design to Specify leak-tight Const for Fan Housing.Shaft Seal Design installed.W/930528 Ltr ML20024G9701991-05-0606 May 1991 LER 91-002-00:on 910406,operating Module Breaker in Automatic Turbine Tester Circuitry Tripped Open,Deenergizing Control Solenoid for change-over Valve.Caused by Use of Undersized Circuit Breaker.Module replaced.W/910506 Ltr ML20029A3331991-02-13013 February 1991 LER 91-001-00:on 910114,Tech Spec Limiting Condition of Operation Action Was Not Satisfied After DG Removed from Standby Svc to Perform Preventive Maint.Caused by Personnel Error.Procedure Changed to Prevent recurrence.W/910213 Ltr ML20044A6881990-06-25025 June 1990 LER 90-009-00:on 900526,nonlicensed Personnel Performed Step Out of Sequence During Breaker rack-out & Caused LPCS Pump Breaker to Close.Operator Involved Counseled on Failure to Adhere to Breaker Operation procedure.W/900625 Ltr ML20043H2951990-06-15015 June 1990 LER 90-007-00:on 900516,discovered That Actions Taken for Inoperable Reactor Water Level Transmitter Not Adequate to Comply W/Requirements for Tech Spec 3.3.2.Caused by Personnel Error.Meetings Held w/personnel.W/900615 Ltr ML20043C6741990-06-0101 June 1990 LER 90-006-00:on 900502,review of Effluent Sample Analysis Revealed That Turbine Bldg Ventilation Exhaust Had Not Been Analyzed Exceeding Time Limit.Caused by Personnel Error. Training & Counseling conducted.W/900601 Ltr ML20042F2251990-05-0404 May 1990 LER 90-005-00:on 900406,discovered That Current Surveillance Practices for Stroke Testing Fresh Air Makeup Intake Valves Could Have Resulted in Unfiltered Pathway.Administrative Controls Placed on valves.W/900504 Ltr ML20012D8071990-03-22022 March 1990 LER 89-018-01:on 891215,determined That Inappropriate Quality Level Designations Applied to Class 1E Circuits, in Violation of Reg Guide 1.75.Caused by Discrepant Instrument Index Controls.Handswitch replaced.W/900228 Ltr ML20012D4801990-03-16016 March 1990 LER 90-003-00:on 900215,identified Potential Single Failure Scenario That Could Result in Unavailability of Both Core Spray Sys for Long Term post-LOCA Core Cooling.Detailed Heatup Evaluation Performed for Power bundle.W/900316 Ltr ML20012A1661990-02-28028 February 1990 LER 90-002-00:on 900124,discovered That Div II Solenoid Associated W/Secondary Containment Isolation Valve Did Not Operate During Quarterly Valve Stroke Time Tests.Caused by Procedure Inadequacy.Procedures changed.W/900227 Ltr ML20006E4521990-02-15015 February 1990 LER 89-015-01:on 891030,no Data or Evidence Found That Stroke Time Test Performed on Bettis Actuator for Isolation Damper Following Maint.Caused by Programmatic Weaknesses.New Computer Field Data Added to Work orders.W/900215 Ltr ML20006E0461990-02-0909 February 1990 LER 90-001-00:on 900112,determined That Tech Spec Reactor Coolant Cooldown Rate Limit of 100 Degrees F Exceeded in Reactor Bottom Head Drain Pipe.Caused by Programmatic Deficiencies.Incident Rept Form improved.W/900209 Ltr ML20006B8731990-01-29029 January 1990 LER 89-019-00:on 891230,total Loss of Plant Svc Water Experienced Due to Loss of Power to Supply Wells.Caused by Malfunction of Microwave Info & Control Sys.Periodic Microwave Operational Checks established.W/900129 Ltr ML20006B2781990-01-16016 January 1990 LER 89-017-00:on 890718,determined That Isolation for Postulated RWCU Blowdown Line Breaks in Piping Cold Rooms Was 80 S,Causing Plant to Operate in Unanalyzed Condition. Tech Spec Change Request Will Be submitted.W/900116 Ltr ML20005G2121990-01-12012 January 1990 LER 89-007-01:on 890508,RWCU Sys Isolated on Leak Detection Differential Flow Signal While Shifting RWCU Operation from pre-pump to post-pump Mode.Probably Caused by Inadequate Reactor Pressure.Procedure revised.W/900112 Ltr ML20005G2071990-01-12012 January 1990 LER 89-018-00:on 891215,design Basis Review of Instrumentation Determined That 71 Devices,Classified as nonsafety-related,contained in Class 1E Circuits.Caused by Level of Control on Instrument index.W/900112 Ltr ML20005D7411989-12-0606 December 1989 LER 89-016-00:on 891107,during Severe Thunderstorm,Lightning Struck Site,Causing Scram & HPCS Low Water Level Channels to Trip.Design Change Package Issued to Install Lightning Dissipation Sys on Vulnerable structures.W/891206 Ltr ML19332F0731989-11-29029 November 1989 LER 89-015-00:on 891030,no Data or Evidence Found for Stroke Time Test Required to Be Performed Following Maint on Bettis Actuator for Isolation Damper QSZ51F001.Caused by Personnel Error.Programmatic Enhancements initiated.W/891129 Ltr ML19325E6971989-10-31031 October 1989 LER 89-008-02:on 890523,two Redundant Secondary Containment Isolation Dampers Failed to Close within 4 Time Limit of Tech Spec 3.6.6.2.Caused by Malfunction of Exhaust Valves. Exhaust Valve replaced.W/891031 Ltr ML19325E6331989-10-27027 October 1989 LER 89-014-00:on 890929,RWCU Sys Isolated on Simulated Steam Line Tunnel High Temp Signal.Caused by Operator Failure to Perform self-verification Prior to Moving Bypass Switch. General Manager Held Briefings w/personnel.W/891027 Ltr ML20024F4561983-08-31031 August 1983 Updated LER 83-001/01X-2:on 830107,electrician Preparing to Route Cable Noticed Two Wall Penetrations Had Been Opened. Because Control Room Not Notified of Work,No Fire Watch in Effect.Caused by Personnel error.W/830831 Ltr ML20024E8741983-08-31031 August 1983 LER 83-108/01T-0:on 830817,radiation Monitor B Trip Setpoint Found High & Grab Samples & Analyses Started Late.Caused by Personnel Error.Personnel counseled.W/830831 Ltr ML20024E9111983-08-30030 August 1983 Updated LER 83-097/03X-1:on 830720,reactor Water Cleanup Auto Isolation Occurred.Caused by Delta Temp Channel B Indicating Temp Above Trip Point Limit.Investigation continuing.W/830830 Ltr ML20024F5091983-08-29029 August 1983 LER 83-112/03L-0:on 830730,while Troubleshooting Initiation Circuitry to Find Reason for Improper Operation of E12F087B & F025B,partial LOCA Signal Occurred.Caused by Error in Work Order.Administrative Fix underway.W/830829 Ltr ML20024F2091983-08-29029 August 1983 LER 83-111/03L-0:on 830730,during Performance of Work Order to Correct Malfunction W/Div I Isolation Reset Status lights,amphenol-type Signal Cable Connector in C/R Panel Disconnected.Caused by Personnel error.W/830829 Ltr ML20024E9311983-08-29029 August 1983 Updated LER 83-002/01X-1:on 830114,personnel Discovered Heat Detectors in Control Room Standby Fresh Air Sys Not Functionally Tested.Caused by Lack of Proper Procedure. Procedure rewritten.W/830829 Ltr ML20024F6131983-08-29029 August 1983 Updated LER 83-010/99X-2:on 830105,fire Protection Deficiencies on Redundant Raceways/Cables Discovered in Auxiliary,Turbine & Control Bldgs.Caused by Incomplete Const.Maint Work Now complete.W/830829 Ltr ML20024F6071983-08-29029 August 1983 Updated LER 82-050/99X-1:on 820806,Fire Detection Zone 2-10 Went Into Alarm Condition & Would Not Clear.Caused by Diesel Exhaust Fumes Drifting Into Corridor.Detectors Cleaned. Design Change submitted.W/830829 Ltr ML20024D8781983-07-29029 July 1983 LER 83-078/03L-0:on 830701,control Room Operators Unable to Maintain Air Receiver Pressure for Diesel Generator 11. Caused by Setpoint Drift on Relief Valves for diesel-driven & Electric motor-driven Air compressors.W/830729 Ltr ML20024D0891983-07-25025 July 1983 LER 83-079/03L-0:on 830625,auxiliary Trip Unit for High Drywell Pressure Indicated Trip Condition Yet No Reactor Protection Sys Trip Occurred.Caused by Defective Rosemount Auxiliary Trip Unit.Trip Unit replaced.W/830725 Ltr ML20024D0761983-07-25025 July 1983 LER 83-080/03L-0:on 830626,control Room Operators Experienced Problems W/Hvac Sys Involving Inadequate Cooling Capacity & Sys Losses.Partially Caused by Malfunctioning Condenser Cooling Water Flow Control valve.W/830725 Ltr ML20024B9941983-06-29029 June 1983 LER 83-072/01T-0:on 830615,operations Shift Supervisor Discovered Some Continuous Fire Watches Not Performed on 830614.Caused by Personnel Error.Personnel Reinstructed Not to Pull Fire Watch W/O approval.W/830629 Ltr ML20024C4031983-06-27027 June 1983 LER 83-071/03L-0:on 830607,RHR Shutdown Cooling Mode Isolated When Valve E12-F009 Closed.Caused by Blown Fuse. Fuse replaced.W/830627 Ltr ML20024B9981983-06-24024 June 1983 LER 83-070/03L-0:on 830525,reactor Water Cleanup Sys Isolated When Standby Liquid Control Pump B Breaker Closed. Caused by Personnel Error.Isolation Signal reset.W/830624 Ltr ML20024C3121983-06-22022 June 1983 LER 83-069/03L-0:on 830523,during Attempt to Reenergize Div II Motor Operated Valves,Shutdown Cooling Mode of RHR Sys & Reactor Water Cleanup Sys Isolated.Caused by Failure to Install Power Fuses.Fuses installed.W/830622 Ltr ML20023E0441983-05-27027 May 1983 Updated LER 83-058/01X-1:on 830311,discovered That Fire Watches Not Conducted in Two Areas of Fire Detection Zone 2-19.Limiting Conditions for Operation Entered on 830227. Caused by Personnel Oversight.Zone restored.W/830527 Ltr ML20023D4331983-05-12012 May 1983 LER 83-046/03L-0:on 830412,monthly Functional Surveillance for Div I Chlorine Detection Sys Not Performed by 830410. Caused by Personnel Error ML20023D4771983-05-11011 May 1983 LER 83-052/03L-0:on 830411,while Reviewing Vessel Head Installation Work Package,Discovered Head Flange/Vessel Flange Thermocouples Not Physically Reinstalled During Insulation Installation.Cause Under Evaluation ML20023C5591983-05-0909 May 1983 Updated LER 83-031/99X-1:on 830113,fire Rated Door OC104 Blocked Open to Route Temporary Discharge Hose from Hot Machine Shop Sump to Turbine Bldg Floor Drain Sys.Caused by Inadequacy of Present Sys.Mod to Be Completed by Sept 1983 ML20023D2511983-05-0909 May 1983 LER 83-049/03L-0:on 830409,during Cold Shutdown,Diesel Generator 12 Auto Start Not Available When Alarm Actuated. Caused by Condensate Drain Valve Downstream of Tank C Not Fully Closed.Compressors Reworked ML20023C5611983-05-0909 May 1983 Updated LER 83-004/01T-1:on 830110,penetration AP-72B Found Open & Had Been Open Since 821213.Caused by Planned Maint Work & Personnel Error.Hourly Fire Watch Established. Penetration to Be Resealed by 830630 ML20023C5511983-05-0909 May 1983 LER 83-048/01T-0:on 830423,suppression Pool Level Instrumentation Discovered Not Functionally Tested Since 830409.Cause Under Investigation.Instrumentation Tested Satisfactorily within 8 H ML20023B5541983-04-28028 April 1983 LER 83-060/03L-0:on 830329,during Cold Shutdown,Load Shedding & Div I LSS Sequencing Panel Failure Alarm Actuated.Caused by Failure of 15-volt Dc Power Supply Used to Power Solid State Electronics for Sys Logic ML20023B6731983-04-27027 April 1983 LER 83-061/03L-0:on 830328,one Solenoid Operated Freon Valve Found W/Blown Gasket.Caused by Defective Alco Controls Solenoid Operated Gasket.Valve Reworked W/Valve Repair Kit & New Gasket Installed ML20028G6031983-02-11011 February 1983 LER 83-019/03L-0:on 830112 & 20,one Smoke Detector in Zone 1-15 & Eight Detectors in Zone 2-18 Covered During Planned Maint Functions to Prevent False Alarms or Damage to Unit. Detectors Uncovered After Maint Completed 1994-04-26
[Table view] Category:RO)
MONTHYEARML20029D0371994-04-26026 April 1994 LER 94-004-00:on 940324,found Five Slow Rods While Scram Time Testing Was Being Performed.Caused by Contamination of Internal Scram Solenoid Pilot Valve Head Assemblies. Corrective Action:Install New Head assemblies.W/940426 Ltr ML20046C3991993-08-0606 August 1993 LER 92-009-01:on 920509,observed That Some of Fuel Rod Compression Springs Compressed More than Expected for Assembly Exposure Achieved.Max Envelope Size of Lower Tie Plate Will Be reduced.W/930806 Ltr ML20045G7911993-07-0808 July 1993 LER 93-005-00:on 930608,indicated That Response Time Test for RCIC Low Steam Pressure Isolation Instrumentation Invalid.Caused by Inappropriate Test Method.Procedures Governing Method of Testing Will Be revised.W/930708 Ltr ML20045E9601993-06-30030 June 1993 LER 92-017-02:on 920804,reactor Scrammed Due to Low Primary Water Tank Level Signal.Implemented Minor Change Package Which Will Install DC to DC Converter Between 24 Volt DC Power Supply & Pw Tank Level transmitters.W/930630 Ltr ML20045C5261993-06-16016 June 1993 LER 93-004-00:on 930517,inboard Containment Isolation Valve Which Supplies Steam to RCIC Sys Automatically Isolated Due to Topaz Inverter Failure.Calibr Instructions & PM Program Will Be reviewed.W/930616 Ltr ML20045A0151993-05-28028 May 1993 LER 92-011-02:on 920608,determined That Design Inadequacies Could Result in Exceeding 10CFR100 Limits.Caused by Failure of Original Design to Specify leak-tight Const for Fan Housing.Shaft Seal Design installed.W/930528 Ltr ML20024G9701991-05-0606 May 1991 LER 91-002-00:on 910406,operating Module Breaker in Automatic Turbine Tester Circuitry Tripped Open,Deenergizing Control Solenoid for change-over Valve.Caused by Use of Undersized Circuit Breaker.Module replaced.W/910506 Ltr ML20029A3331991-02-13013 February 1991 LER 91-001-00:on 910114,Tech Spec Limiting Condition of Operation Action Was Not Satisfied After DG Removed from Standby Svc to Perform Preventive Maint.Caused by Personnel Error.Procedure Changed to Prevent recurrence.W/910213 Ltr ML20044A6881990-06-25025 June 1990 LER 90-009-00:on 900526,nonlicensed Personnel Performed Step Out of Sequence During Breaker rack-out & Caused LPCS Pump Breaker to Close.Operator Involved Counseled on Failure to Adhere to Breaker Operation procedure.W/900625 Ltr ML20043H2951990-06-15015 June 1990 LER 90-007-00:on 900516,discovered That Actions Taken for Inoperable Reactor Water Level Transmitter Not Adequate to Comply W/Requirements for Tech Spec 3.3.2.Caused by Personnel Error.Meetings Held w/personnel.W/900615 Ltr ML20043C6741990-06-0101 June 1990 LER 90-006-00:on 900502,review of Effluent Sample Analysis Revealed That Turbine Bldg Ventilation Exhaust Had Not Been Analyzed Exceeding Time Limit.Caused by Personnel Error. Training & Counseling conducted.W/900601 Ltr ML20042F2251990-05-0404 May 1990 LER 90-005-00:on 900406,discovered That Current Surveillance Practices for Stroke Testing Fresh Air Makeup Intake Valves Could Have Resulted in Unfiltered Pathway.Administrative Controls Placed on valves.W/900504 Ltr ML20012D8071990-03-22022 March 1990 LER 89-018-01:on 891215,determined That Inappropriate Quality Level Designations Applied to Class 1E Circuits, in Violation of Reg Guide 1.75.Caused by Discrepant Instrument Index Controls.Handswitch replaced.W/900228 Ltr ML20012D4801990-03-16016 March 1990 LER 90-003-00:on 900215,identified Potential Single Failure Scenario That Could Result in Unavailability of Both Core Spray Sys for Long Term post-LOCA Core Cooling.Detailed Heatup Evaluation Performed for Power bundle.W/900316 Ltr ML20012A1661990-02-28028 February 1990 LER 90-002-00:on 900124,discovered That Div II Solenoid Associated W/Secondary Containment Isolation Valve Did Not Operate During Quarterly Valve Stroke Time Tests.Caused by Procedure Inadequacy.Procedures changed.W/900227 Ltr ML20006E4521990-02-15015 February 1990 LER 89-015-01:on 891030,no Data or Evidence Found That Stroke Time Test Performed on Bettis Actuator for Isolation Damper Following Maint.Caused by Programmatic Weaknesses.New Computer Field Data Added to Work orders.W/900215 Ltr ML20006E0461990-02-0909 February 1990 LER 90-001-00:on 900112,determined That Tech Spec Reactor Coolant Cooldown Rate Limit of 100 Degrees F Exceeded in Reactor Bottom Head Drain Pipe.Caused by Programmatic Deficiencies.Incident Rept Form improved.W/900209 Ltr ML20006B8731990-01-29029 January 1990 LER 89-019-00:on 891230,total Loss of Plant Svc Water Experienced Due to Loss of Power to Supply Wells.Caused by Malfunction of Microwave Info & Control Sys.Periodic Microwave Operational Checks established.W/900129 Ltr ML20006B2781990-01-16016 January 1990 LER 89-017-00:on 890718,determined That Isolation for Postulated RWCU Blowdown Line Breaks in Piping Cold Rooms Was 80 S,Causing Plant to Operate in Unanalyzed Condition. Tech Spec Change Request Will Be submitted.W/900116 Ltr ML20005G2121990-01-12012 January 1990 LER 89-007-01:on 890508,RWCU Sys Isolated on Leak Detection Differential Flow Signal While Shifting RWCU Operation from pre-pump to post-pump Mode.Probably Caused by Inadequate Reactor Pressure.Procedure revised.W/900112 Ltr ML20005G2071990-01-12012 January 1990 LER 89-018-00:on 891215,design Basis Review of Instrumentation Determined That 71 Devices,Classified as nonsafety-related,contained in Class 1E Circuits.Caused by Level of Control on Instrument index.W/900112 Ltr ML20005D7411989-12-0606 December 1989 LER 89-016-00:on 891107,during Severe Thunderstorm,Lightning Struck Site,Causing Scram & HPCS Low Water Level Channels to Trip.Design Change Package Issued to Install Lightning Dissipation Sys on Vulnerable structures.W/891206 Ltr ML19332F0731989-11-29029 November 1989 LER 89-015-00:on 891030,no Data or Evidence Found for Stroke Time Test Required to Be Performed Following Maint on Bettis Actuator for Isolation Damper QSZ51F001.Caused by Personnel Error.Programmatic Enhancements initiated.W/891129 Ltr ML19325E6971989-10-31031 October 1989 LER 89-008-02:on 890523,two Redundant Secondary Containment Isolation Dampers Failed to Close within 4 Time Limit of Tech Spec 3.6.6.2.Caused by Malfunction of Exhaust Valves. Exhaust Valve replaced.W/891031 Ltr ML19325E6331989-10-27027 October 1989 LER 89-014-00:on 890929,RWCU Sys Isolated on Simulated Steam Line Tunnel High Temp Signal.Caused by Operator Failure to Perform self-verification Prior to Moving Bypass Switch. General Manager Held Briefings w/personnel.W/891027 Ltr ML20024F4561983-08-31031 August 1983 Updated LER 83-001/01X-2:on 830107,electrician Preparing to Route Cable Noticed Two Wall Penetrations Had Been Opened. Because Control Room Not Notified of Work,No Fire Watch in Effect.Caused by Personnel error.W/830831 Ltr ML20024E8741983-08-31031 August 1983 LER 83-108/01T-0:on 830817,radiation Monitor B Trip Setpoint Found High & Grab Samples & Analyses Started Late.Caused by Personnel Error.Personnel counseled.W/830831 Ltr ML20024E9111983-08-30030 August 1983 Updated LER 83-097/03X-1:on 830720,reactor Water Cleanup Auto Isolation Occurred.Caused by Delta Temp Channel B Indicating Temp Above Trip Point Limit.Investigation continuing.W/830830 Ltr ML20024F5091983-08-29029 August 1983 LER 83-112/03L-0:on 830730,while Troubleshooting Initiation Circuitry to Find Reason for Improper Operation of E12F087B & F025B,partial LOCA Signal Occurred.Caused by Error in Work Order.Administrative Fix underway.W/830829 Ltr ML20024F2091983-08-29029 August 1983 LER 83-111/03L-0:on 830730,during Performance of Work Order to Correct Malfunction W/Div I Isolation Reset Status lights,amphenol-type Signal Cable Connector in C/R Panel Disconnected.Caused by Personnel error.W/830829 Ltr ML20024E9311983-08-29029 August 1983 Updated LER 83-002/01X-1:on 830114,personnel Discovered Heat Detectors in Control Room Standby Fresh Air Sys Not Functionally Tested.Caused by Lack of Proper Procedure. Procedure rewritten.W/830829 Ltr ML20024F6131983-08-29029 August 1983 Updated LER 83-010/99X-2:on 830105,fire Protection Deficiencies on Redundant Raceways/Cables Discovered in Auxiliary,Turbine & Control Bldgs.Caused by Incomplete Const.Maint Work Now complete.W/830829 Ltr ML20024F6071983-08-29029 August 1983 Updated LER 82-050/99X-1:on 820806,Fire Detection Zone 2-10 Went Into Alarm Condition & Would Not Clear.Caused by Diesel Exhaust Fumes Drifting Into Corridor.Detectors Cleaned. Design Change submitted.W/830829 Ltr ML20024D8781983-07-29029 July 1983 LER 83-078/03L-0:on 830701,control Room Operators Unable to Maintain Air Receiver Pressure for Diesel Generator 11. Caused by Setpoint Drift on Relief Valves for diesel-driven & Electric motor-driven Air compressors.W/830729 Ltr ML20024D0891983-07-25025 July 1983 LER 83-079/03L-0:on 830625,auxiliary Trip Unit for High Drywell Pressure Indicated Trip Condition Yet No Reactor Protection Sys Trip Occurred.Caused by Defective Rosemount Auxiliary Trip Unit.Trip Unit replaced.W/830725 Ltr ML20024D0761983-07-25025 July 1983 LER 83-080/03L-0:on 830626,control Room Operators Experienced Problems W/Hvac Sys Involving Inadequate Cooling Capacity & Sys Losses.Partially Caused by Malfunctioning Condenser Cooling Water Flow Control valve.W/830725 Ltr ML20024B9941983-06-29029 June 1983 LER 83-072/01T-0:on 830615,operations Shift Supervisor Discovered Some Continuous Fire Watches Not Performed on 830614.Caused by Personnel Error.Personnel Reinstructed Not to Pull Fire Watch W/O approval.W/830629 Ltr ML20024C4031983-06-27027 June 1983 LER 83-071/03L-0:on 830607,RHR Shutdown Cooling Mode Isolated When Valve E12-F009 Closed.Caused by Blown Fuse. Fuse replaced.W/830627 Ltr ML20024B9981983-06-24024 June 1983 LER 83-070/03L-0:on 830525,reactor Water Cleanup Sys Isolated When Standby Liquid Control Pump B Breaker Closed. Caused by Personnel Error.Isolation Signal reset.W/830624 Ltr ML20024C3121983-06-22022 June 1983 LER 83-069/03L-0:on 830523,during Attempt to Reenergize Div II Motor Operated Valves,Shutdown Cooling Mode of RHR Sys & Reactor Water Cleanup Sys Isolated.Caused by Failure to Install Power Fuses.Fuses installed.W/830622 Ltr ML20023E0441983-05-27027 May 1983 Updated LER 83-058/01X-1:on 830311,discovered That Fire Watches Not Conducted in Two Areas of Fire Detection Zone 2-19.Limiting Conditions for Operation Entered on 830227. Caused by Personnel Oversight.Zone restored.W/830527 Ltr ML20023D4331983-05-12012 May 1983 LER 83-046/03L-0:on 830412,monthly Functional Surveillance for Div I Chlorine Detection Sys Not Performed by 830410. Caused by Personnel Error ML20023D4771983-05-11011 May 1983 LER 83-052/03L-0:on 830411,while Reviewing Vessel Head Installation Work Package,Discovered Head Flange/Vessel Flange Thermocouples Not Physically Reinstalled During Insulation Installation.Cause Under Evaluation ML20023C5591983-05-0909 May 1983 Updated LER 83-031/99X-1:on 830113,fire Rated Door OC104 Blocked Open to Route Temporary Discharge Hose from Hot Machine Shop Sump to Turbine Bldg Floor Drain Sys.Caused by Inadequacy of Present Sys.Mod to Be Completed by Sept 1983 ML20023D2511983-05-0909 May 1983 LER 83-049/03L-0:on 830409,during Cold Shutdown,Diesel Generator 12 Auto Start Not Available When Alarm Actuated. Caused by Condensate Drain Valve Downstream of Tank C Not Fully Closed.Compressors Reworked ML20023C5611983-05-0909 May 1983 Updated LER 83-004/01T-1:on 830110,penetration AP-72B Found Open & Had Been Open Since 821213.Caused by Planned Maint Work & Personnel Error.Hourly Fire Watch Established. Penetration to Be Resealed by 830630 ML20023C5511983-05-0909 May 1983 LER 83-048/01T-0:on 830423,suppression Pool Level Instrumentation Discovered Not Functionally Tested Since 830409.Cause Under Investigation.Instrumentation Tested Satisfactorily within 8 H ML20023B5541983-04-28028 April 1983 LER 83-060/03L-0:on 830329,during Cold Shutdown,Load Shedding & Div I LSS Sequencing Panel Failure Alarm Actuated.Caused by Failure of 15-volt Dc Power Supply Used to Power Solid State Electronics for Sys Logic ML20023B6731983-04-27027 April 1983 LER 83-061/03L-0:on 830328,one Solenoid Operated Freon Valve Found W/Blown Gasket.Caused by Defective Alco Controls Solenoid Operated Gasket.Valve Reworked W/Valve Repair Kit & New Gasket Installed ML20028G6031983-02-11011 February 1983 LER 83-019/03L-0:on 830112 & 20,one Smoke Detector in Zone 1-15 & Eight Detectors in Zone 2-18 Covered During Planned Maint Functions to Prevent False Alarms or Damage to Unit. Detectors Uncovered After Maint Completed 1994-04-26
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217F9921999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for Grand Gulf Nuclear Station,Unit 1.With ML20212F5641999-09-23023 September 1999 SER Concluding That All of ampacity-related Concerns Have Been Resolved & Licensee Provided Adequate Technical Basis to Assure That All of Thermo-Lag Fire Barrier Encl Cables Operating within Acceptable Ampacity Limits ML20211Q3171999-09-0909 September 1999 Safety Evaluation Accepting BWROG Rept, Prediction of Onset of Fission Gas Release from Fuel in Generic BWR, Dtd July 1996 ML20216E4881999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Grand Gulf Nuclear Station.With ML20211A6921999-07-31031 July 1999 Monthly Operating Rept for July 1999 for Grand Gulf Nuclear Station,Unit 1.With ML20209J1961999-07-12012 July 1999 Special Rept 99-001:on 990528,smoke Detectors Failed to Alarm During Performance of Routine Channel Functional Testing.Applicable TRM Interim Compensatory Measure of Establishing Roving Hourly Fire Patrol Was Implemented ML20196K4981999-07-0101 July 1999 Safety Evaluation Authorizing PRR-E12-01,PRR-E21-01, PRR-P75-01,PRR-P81-01,VRR-B21-01,VRR-B21-02,VRR-E38-01 & VRR-E51-01.Concludes That Alternatives Proposed by EOI Acceptable ML20209G0691999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Grand Gulf Nuclear Station,Unit 1.With ML20196A1161999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Grand Gulf Nuclear Station.With ML20206Q4831999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Grand Gulf Nuclear Station Unit 1.With ML20206J1201999-04-30030 April 1999 Redacted ME-98-001-00, Pressure Locking & Thermal Binding Test Program on Two Gate Valves with Limitorque Actuators ML18016A9011999-04-12012 April 1999 Part 21 Rept Re Defect in Component of DSRV-16-4,Enterprise DG Sys.Caused by Potential Problem with Connecting Rod Assemblies Built Since 1986,that Have Been Converted to Use Prestressed Fasteners.Affected Rods Should Be Inspected ML20205P8771999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Grand Gulf Nuclear Station,Unit 1.With ML20207M9231999-03-12012 March 1999 Amended Part 21 Rept Re Cooper-Bessemer Ksv EDG Power Piston Failure.Total of 198 or More Pistons Have Been Measured at Seven Different Sites.All Potentially Defective Pistons Have Been Removed from Svc Based on Encl Results ML20207K5141999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Grand Gulf Nuclear Station,Unit 1.With ML20206T7991999-01-31031 January 1999 Iodine Revolatizitation in Grand Gulf Loca ML20207A8301998-12-31031 December 1998 1998 Annual Operating Rept for Ggns,Unit 1 ML20206R9501998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for Grand Gulf Nuclear Station,Unit 1.With ML20206D7721998-12-31031 December 1998 South Mississippi Electric Power Association 1998 Annual Rept ML20198E2481998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Grand Gulf Nuclear Station,Unit 1.With ML20195F4121998-11-13013 November 1998 Rev 16 to GGNS-TOP-1A, Operational QA Manual (Oqam) ML20195C4841998-11-0606 November 1998 SER Accepting QA Program Change to Consolidate Four Existing QA Programs for Arkansas Nuclear One,Grand Gulf Nuclear Station,River Bend Station & Waterford 3 Steam Electric Station Into Single QA Program ML20195C2791998-11-0505 November 1998 BWR Feedwater Nozzle Inservice Insp Summary Rept for GGNS, NUREG-0619-00006 ML20195F4801998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Grand Gulf Nuclear Station,Unit 1.With ML20155C1351998-10-26026 October 1998 Rev B to Entergy QA Program Manual ML20154K2391998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Grand Gulf Nuclear Station Unit 1.With ML20155F1961998-09-0101 September 1998 Engineering Rept for Evaluation of BWR CR Drive Mounting Flange Cap Screw ML20153B2161998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for Grand Gulf Nuclear Station,Unit 1.With ML20237B6661998-07-31031 July 1998 Monthly Operating Rept for Jul 1998 for Grand Gulf Nuclear Station,Unit 1 ML20236R0231998-06-30030 June 1998 Monthly Operating Rept for June 1998 for Grand Gulf Nuclear Station,Unit 1 ML20155J0811998-05-31031 May 1998 10CFR50.59 SE for Period Jan 1997 - May 1998 ML20249B1251998-05-31031 May 1998 Monthly Operating Rept for May 1998 for Grand Gulf Nuclear Station,Unit 1 ML20248B6261998-05-11011 May 1998 Rev 6 to Grand Gulf Nuclear Station COLR Safety-Related ML20217Q6701998-05-0606 May 1998 SER Approving Proposed Postponement of Beginning Augmented Exam Requirements of 10CFR50.55a(g)(6)(ii)(A)(2) at Grand Gulf for Circumferential Shell Welds for Two Operating Cycles ML20206J1271998-04-30030 April 1998 Pressure Locking Thrust Evaluation Methodology for Flexible Wedge Gate Valves ML20247F3591998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for Grand Gulf Nuclear Plant,Unit 1 ML20217M8951998-04-30030 April 1998 QA Program Manual ML20217P8281998-04-0707 April 1998 Safety Evaluation Accepting Relief Authorization for Alternative to Requirements of ASME Section Xi,Subarticle IWA-5250 Bolting Exam for Plants,Per 10CFR50.55a(a)(3)(i) ML20217P0381998-04-0606 April 1998 Safety Evaluation Supporting Amend 135 to License NPF-29 ML20217A0291998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for Grand Gulf Nuclear Sation,Unit 1 ML20216J4211998-03-18018 March 1998 SER Approving Alternative to Insp of Reactor Pressure Vessel Circumferential Welds for Grand Gulf Nuclear Station ML20216J2021998-02-28028 February 1998 Monthly Operating Rept for Feb 1998 for Grand Gulf Nuclear Station,Unit 1 ML20203A2891998-01-31031 January 1998 Monthly Operating Rept for Jan 1998 for Grand Gulf Nuclear Station ML20247B4111997-12-31031 December 1997 1997 Annual Financial Rept for South Mississippi Electric Power Association ML20203H9741997-12-31031 December 1997 1997 Annual Operating Rept, for Ggns,Unit 1 ML20198P1121997-12-31031 December 1997 Monthly Operating Rept for Dec 1997 for Grand Gulf Nuclear Station,Unit 1 ML20203B5581997-12-0404 December 1997 Special Rept 97-003:on 971111,valid Failure of Div 2 EDG Occurred,Due to Jacket Water Leak.Failure Reported,Per Plant Technical Requirements Manual Section 7.7.2.2 ML20203K4031997-11-30030 November 1997 Monthly Operating Rept for Nov 1997 for Grand Gulf Nuclear Station,Unit 1 ML20199H3711997-11-19019 November 1997 SER Accepting Approving Request Relief from Requirements of Section XI, Rule for Inservice Insp of NPP Components, of ASME for Current or New 10-year Inservice Insp Interval IAW 50.55(a)(3)(i) of 10CFR50 ML20199F3431997-11-18018 November 1997 SER Accepting Rev 15 of Operational Quality Assurance Manual for Grand Gulf Nuclear Station,Unit 1 1999-09-09
[Table view] |
Text
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Aw e .s=m uwm compaw vce nesorv october 31, 1989
.- Nucks Opactons :
.U.S. Nuclear Regulatory Commission !
. Mail Station P1-137
' . Washington .
D.C. 20555
- Attention
- Document Control Desk i g ..
f~ Gentlemen: I I
SUBJECT:
Grand Gulf Nuclear Station r Unit 1 Docket No. 50-416 l License No. NPF-29 l
, Update on The Failure of Redundant ,
Isolation Dampers i LER 89-008-02 i
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AECM-89/0304 )
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Attached is Licensee Event Report (LER) 89-008-02 which is a final j report, i Yours truly, e
WTC:cg-Attachment l cc:. Mr. D. C. Hintz (w/a)
Mr. T. H. Cloninger (w/c)
Mr.'R. B. McGehee (w/a)
Mr. N. S. Reynolds (w/a) '
Mr.11. L. Thomas (w/o) l Mr. H. O. Christensen (w/a) )
Mr. Stewart D. Ebneter (w/a) l i
Regional Administrator l U.S. Nuclear Regulatory Commission !
Region II I 101 Marietta St. , N.W. , Suite 2900 I
. Atlanta, Georgia 30323 l l
Mr. L. L. Kintner, Project Manager (w/a) .
Office of Nuclear Reactor Regulation i U.S. Nuclear Regulatory Commission l
, Mail Stop 14B20 i Washington, D.C. 20555 l 891108'0590 89103L k
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on May 23, 1989 two redundant secondt.ry containment isolation dampers.
Q1T42F019 and QlT42T020, failed to close within the 4 second time limit of Technical Specification 3.6.6.2. It was suspected that the internal disk of each exhaust valve, which shuttleu *o vent or admit air on the actuator i cylinder f ailed to properly lif t tc, vent air pressure during initial attempts to close the dampers. The exhaust valve associated with the actuator of each damper was replaced. SERI will remove these type exhaust valves on all safety-related Bettis actuators and replace existing solenoid valves with valves having larger orifices and air tubing to achieve the same required stroke time.
On June 16, 1989, the QlT42F020 damper again failed to close within the 4 second time limit. The damper actuator was disassembled and no obvious r failures or defects were observed. The actuator containrd Mob 11 grease 28 which was previously identified in a 10CFR21 report as having a tendency to cause seals to swell and produce slower stroke times. Ilowever, this model of actuator was not projected to degrade in stroking time. This was not initially considered a potential contributor since the QlT42T019 had been refurbished and ,
lubricated with the approved Molykote 44 during the third refueling outage.
Grand Gulf has a 5 year program to refurbish 3ettis actuators which ensures that Molykote 44 is used. All except 2 actuators in this program have now been rebuilt. An evaluation found rose variance between the seals removed from the actuators and new seals, but it could not be conclusively determined if interaction with Mob 11 grease 28 was a factor. After consultation with the vendor, it is SERI's judgement that seal swelling was not c cause of the event.
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I A. REPORTABLE OCCURRENCE Oa May 23, 1989, two redundant secondary containment isolation f dampers failed to close within the 4 second time limit of !
Technical Specificar,1on 3.6.6.2. This condition is reported l pursuant to 10CTR50.73 (a)(2)(v).
B. INITIAL CONDITIONS i l
The plant was in Operational Condition 4. Cold Shutdown, at the !
time of the occurrence. [
i C. DESCRIPTION OF OCCURRENCE i On May 23, 1989 at 0235, operators manually initiated Sta.ndby Gas l Treatment Systems (SGTS) A and B. This planned initiation was ,
taken as a precautionary measure while transporting the contaninated 'B' recirc pump upper shroud from the cask washdown .-
area to the refueling floor. The 'B' recirc pump had been !
l recently removed for disassembly and inspection to determine the cause of high vibration.
[
k' hon the SGTS (E11S System code BH) was initiated two secondary containment isolation dampers failed to close within the allowed i stroke time. The two dampers, QlT42r019 and QlT42F020 are .
installed in series to isolate the outside air supply to the fuel l pool sweep fans (EIIS System code: VG). QlT42F019 is powered from i electrical division 1 and QlT42T020 is powered from electrical division 2.
Approximately 15 seconds after initiation, the Control Roon l operator placed both damper handswitches to the closed position. ;
The QlT42F020 damper closed slowly, but the QlT42F019 damper did ,
not initia.11y close. The operator cycled the handswitch for QlT42F019 from AUTO to CLOSE repeatedly. The damper closed approximately 30 to 45 seconds after the last closure attempt '
(approximately 1 minute after the SGTS initiation).
D. APPARENT CAUSE Initial investigations into the occurrence included the initiation of SGTS "A" and "B" again to aid in the investigation. However, both dampers closed in less than 4 seconds with no work having been performed on the dampers, actuators, or controls.
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l Each isolation damper is held open by air pressure on the l actuator cylinder and is closed by spring force. The most likely cause of this failure was believed to be a simultaneous malfunction of the exhaust valves which help vent the air from i each actuator. One of the shuttle disks was inspected and found to have some deformation where contact is made with the outlet i port of the exhaust valve. It was concluded that the internal l disk of each exhaust valve which shuttles to vent or admit air on !
the actuator cylinder, failed to properly lift to vent air !
pressure during the initial attempt to close the dampers. The ,
exhaust valve associated with the actuator of each desper was :
replaced. A removed exhaust valve was shipped to the vendor for [
an assessment of possible malfunction. l t On June 16, 1989, the Control Room Operator manually initiated i Standby Gas Treatment System (SGTS) B as a retest following !
scheduled maintenance. Upon initiation, the QlT42F020 isolation ;
damper again failed to close within the required Technical ,
Specification stroke time. The damper closed slowly (approximately 45 seconds later). !
Following the second occurrence. the QlT42F020 damper actuator ;
was disassembled for inspection. The inspection did not reveal f any obvious failures or defects which would have caused the slow i closure. However, it was determined that the actuator contained .
l Mobilgrease 28. The GH Bettis Company reported in February 1984 l l per 10CTR21, that Mobilgrease 28 as a lubricant could cause swelling l of the ethylene propylene seals in the actuator. The model of actuator installed on these dampers was not projected to degrade in stroking time.
The lubricant was not considered to be a potential contributor !
at the time of the first incident since the QlT42F019 actuator had !
previously been refurbished and lubricated with the approved i Molykote 44 lubricant during the third refueling outage. The '
actuator for QlT42F020 was subsequently reassembled with the approved Molykote 44 lubricant.
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PCOM LER 89-008-02
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E. SUPPLEMENTAL CORRECTIVE ACTIONS [
l The QlT42F019 and QlT42F020 dampers are normally cycled on a >
quarterly basis to confirm that the 4 second isolation requirement !
of Technical Specificatien 3.6.6.2 is met. In addition, the dampers i are typically stroked every month during the SGTS functional surveillance. l
, As a result of this event, QlT42F019 and QlT42F020 dampers were cycled on ;
an increased frequency of at least one:e every 15 days. After obtaining }
acceptable results, the test frequency was reverted to once per quarter.
Operation of the dempers will continue to be monitored during the monthly .
SGTS functional surveillance, j System Engineering dimensionally compared the actustor seals to new seals obtained from warehouse stock to determine what affect, if any. ,
the Mob 11 grease 28 may have had on the seals and the closing of the dampers. Although there were some differences in seal diameters, no !
comparative data could he obtained from G. H. F.ettis or Enertech to ;
substantiate that the difference was caused by seal swelling due to l interaction with Mob 11 grease 28. After consultation with the vendor, it !
is SERI's judgement that seal swelling was not the cause of the problem I with the QlT42F020 damper.
At the time of the submittal of LER-89-008-00 there were eight (8)
Bettis actuators that had not been rebuilt under the $ year refurbishment (
program. This program ensures that approved Holykote 44 is used as a i lubricant. These eight (8) actuators were not projected to degrade in '
stroking time as described in the 10CFR21 report. Two of these actuators are normally closed and only stroke tested during cold shutdown. These ;
two (2) actuators will be stroke tested and refurbished prior to startup [
from the next refueling outage (RF04). The other six (6) actuators have ;
now been rebuilt using the approved Holykote 44 lubricant and retested ;
satisfactorily. The previous stroke tests prior to refurbishment were ;
also acceptable. t System Engineering conducted a review which included system l walkdowns and inspections to identify any potential conson mode failure mechanisms. The only other potential common mode failure i mechanisms identified which could have contributed to the slow stroke '
times were the solenoid valves. The solenoid valve in the air supply '
for QlT42F020 was disassembled and' inspected by engineering personnel. ;
There was no evidsnee of any abnormality or defect which would have '
caused a malfunction. Testing of the solenoid prior to disassembly demonstrated that it was functioning properly. System Engineering is reviewing industry experience with ASCO Solenoid Valve Model NP831655E to determine if there are any previously identified problems that could ,
cause abnormal operation. ,
PCOM LER 89-008-02 4
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The exhaust valve vendor, parker Hannifan, reported that there were no I known generic problems associated with this type of exhaust valve.
However SERI will discontinue using the exhaust valves in safety-related applications to eliminate the possibility of their failure. These type exhaust valves will be removed from all safety-related Bettis actuators and existing electric solenoid valves will be replaced with valves having j larger orifices and air tubing to achieve the required stroke time. ;
The change will be completed prior to startup from the fourth refueling 1 outage (RF04).
Namco recently informed customers of potential problems with Model )
EA740 and EA750 limit switches sticking due to lubrication problems. The QlT42F019 and QlT42F020 dampers utilize Namco Model EA740 limit switches which may have caused an erroneous indication of damper position. However, !
since dual indication of damper position was not received in the Control !
Room and since the probability of a double failure of the contacts in the ,
signal circuit is low, the limit evitches are not a likely contributor to i the occurrence. Investigation of this possibility is in progress. f I
This report is submitted as a final report. Although the root cause was ,
not conclusively determined, the actions taken to date and the actions ;
planned are considered adequate to pr'eclude recurrence. There have been !
no recurrences since June 16, 1989. t F. SAFETY ASSESSMENT ;
The QlT42F019 and QlT42F020 dampers are the only secondary 3 containment isolation dampers in the outside air supply i penetration to the fuel pool sweep fans. The concurrent failure of both dampers to isolate within the required 4 seconds could l adversely affect the required drawdown time of secondary
occurrence.
After the second occurrence on June 16, 1989, QlT4?F019 was secured in the isolated position in accordance with Action b of ;
Technical Specification 3.6.6.2. The valve properly operated to 16olate the penetration within the required 4 seconds. '
f W"pCOM LER 89-008-02
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