LER 93-017-00:on 930527,determined That Feedwater Isolation Bypass Valves Inoperable Since Pneumatic Positioner & Solenoids Remained in Svc Beyond Qualified Life.Caused by Incorrect Interpretation of Design Documents.Mod UnderwayML20045E153 |
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Site: |
South Texas |
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Issue date: |
06/25/1993 |
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From: |
Pinzon J HOUSTON LIGHTING & POWER CO. |
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To: |
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Shared Package |
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ML20045E151 |
List: |
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References |
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LER-93-017, LER-93-17, NUDOCS 9307010186 |
Download: ML20045E153 (8) |
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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20029D6321994-05-0202 May 1994 LER 94-002-01:on 940115,centrifugal Charging Pump 1A Discharge Bypass Valve Found in Open Position Contrary to Requirements of TS 3.1.2.3.Caused by hydro-pneumatic Transient.Valves Labeled W/Caution statements.W/940502 Ltr ML20029D6351994-04-27027 April 1994 LER 94-006-01:on 940214,reactor Manually Tripped Following Unanticipated Test Results.Caused by Mod Which Failed post- Mod Test.Test Terminated & Solid State Rod Control Sys Returned to Original Design configuration.W/940427 Ltr ML20029C6951994-04-18018 April 1994 LER 94-011-00:on 940310,safety Injection Actuation Was Received on Trains A,B & C.Cause Was Failure to Adhere to Procedure.Corrective Actions:Restored Cooling Shutdown & Removed Personnel from watchbill.W/940418 Ltr ML17352B2581994-03-25025 March 1994 LER 94-007-00:on 940224,station Procedure for Testing Reactor Trip Bypass Breakers Did Not Satisfy Ts.Caused by Inadequate Procedure Preparation & Review.Surveillance Procedure Enhancement Program underway.W/940325 Ltr ML20046C5471993-08-0606 August 1993 LER 93-018-00:on 930707,discovered Remote Position Indication Verification Test for SI Sys Accumulator Vent & Header Valves Had Not Been Performed in 2 Yrs Due to Change to IST plan.W/930806 Ltr ML20046C4901993-08-0505 August 1993 LER 93-019-00:on 930709,determined That TS Requirement of MSIV Was Not Met Due to Inadequate Design of Field Change to Testing Function of Solid State Protection Sys.Corrected Missing Jumpers & Overlap Testing discrepancy.W/930805 Ltr ML20046B1291993-07-29029 July 1993 LER 93-012-00:on 930614,lost Spent Fuel Pool Cooling for Approx 13 Hours Due to Insufficient Control Board Awareness. Design Change to Install Annunciator in Control Room to Inform of Loss of Spent Fuel cooling.W/930729 Ltr ML20046A6791993-07-21021 July 1993 LER 93-011-00:on 930401,pressurizer Safety Valve Setpoints Found Outside Required TS Tolerance.Caused by Setpoint Drift Due to Inherent Valve Characteristics.Mod of Test Procedures Underway ML20046A6511993-07-20020 July 1993 LER 93-017-01:on 930527,concluded That,Based on 930521 Determination,That Feedwater Isolation Bypass Valves Inoperable Since Pneumatic Positioners & Solenoids Remained in Svc Beyond Qualified Life.Control Scheme Modified ML20045J0281993-07-15015 July 1993 LER 93-016-01:on 930503,TS Violations Occurred Due to Circuitry for SG Power Operated Relief Valves & Post Accident Monitoring Instruments Being Inoperable.Replaced Missing Screws from Unit 1 QDPS.W/930715 Ltr ML20045H9171993-07-14014 July 1993 LER 93-008-01:on 930505,discovered That RHR Pump Suction MOV Had Not Been Environ Qualified Since 901129 Because Replacement of Drain T Not Completed.Drain T Missing from RH-0060B Replaced & Bulletin Issued to Maint Dept ML20045H9881993-07-13013 July 1993 LER 93-012-01:on 930405,TS Violation Occurred Due to Incorrect Settings of Several Molded Case Circuit Breakers. Reset Affected Unit 1 Breakers to Correct Settings. W/930713 Ltr ML20045E1531993-06-25025 June 1993 LER 93-017-00:on 930527,determined That Feedwater Isolation Bypass Valves Inoperable Since Pneumatic Positioner & Solenoids Remained in Svc Beyond Qualified Life.Caused by Incorrect Interpretation of Design Documents.Mod Underway ML20045E1491993-06-25025 June 1993 LER 93-010-00:on 930526,discovered That Screen Drive Coupling on Essential Cooling Water Traveling Screen 2A Damaged.Caused by Aging of Elastomeric Element.Couplings Replaced & Preventive Maint initiated.W/930625 Ltr ML20045B2731993-06-0909 June 1993 LER-93-016-00:on 930503,TS Violation Occured Due to Circuitry for SG PORVs & RCS Subcooling Monitor Being Inoperable.Caused by Less than Adequate Work Practices. Screws Missings from Qdps Replaced & Walkdown Performed ML20045A3831993-06-0404 June 1993 LER 93-008-00:on 930505,heat Removal Motor Operated Valve Inoperable in Excess of Allowable Outage Time.Caused by Failure to Recognize Condition.Condition Corrected by Replacing T Drain ML20044G4301993-05-25025 May 1993 LER 93-009-00:on 930426,Tech Spec Violation Occurred Due to Use of Inappropriate Ref Value Data for RHR Pump Inservice Test.Surveillance Procedures Revised to Include Appropriate Ref values.W/930525 Ltr ML20044F6281993-05-21021 May 1993 LER 93-015-00:on 930423,plant Personnel Determined That May 1990 Control Room Makeup & Cleanup Filtration Sys Svc Time Exceeded.Caused by Failure to Develop Run H Tracking Method. Run Times for Cleanup & Makeup Fans monitored.W/930521 Ltr ML20044F1321993-05-20020 May 1993 LER 93-009-01:on 930217,TS 3.0.3 Entered Due to Potentially Undersized Fuses in Ssps.Caused by Random Age Related Failure of Ssps Fuse.Fuses in Selected Equipment Replaced During Fuse & Breaker Field Verification Effort ML20044E0371993-05-14014 May 1993 LER 93-005-01:on 930214,control Room Operator Left CR Unmanned During Mode 4 Operation for 41 S.Caused by Inappropriate Action by Unit Supervisor.Event Will Be Included in Licensed Operator Requalification Training ML20024H2571991-05-24024 May 1991 LER 91-014-00:on 910420,erratic Containment Extended Range Pressure Channel Output Occurred.Caused by Bad Control Card. Weekly Channel Checks Performed,Control Card Replaced & Channel calibrated.W/910524 Ltr ML20024H2081991-05-22022 May 1991 LER 91-015-00:on 910422,train C AFW Pump Inadvertently Started Due to Failure of Led in Sequencer Test Circuitry. Faulty Led Replaced & Blocking Circuit Satisfactorily tested.W/910522 Ltr ML20029C1221991-03-15015 March 1991 LER 91-004-00:on 910215,loss of Offsite Power Actuation Occurred During Routine Maint.Caused by Lack of Attention to Work Performance Methods.Training Conducted for Maintenance personnel.W/910315 Ltr ML20029B0421991-02-25025 February 1991 LER 91-002-00:on 910126,automatic Actuation of Safety Injection Sys Occurred in One of Three Train C Trains.Caused by Inadequate Work Instructions for Maint Activity.Training Bulletin Issued & Supervisors counseled.W/910225 Ltr ML20024F7451990-12-12012 December 1990 LER 90-017-00:on 901104,discovered That Train a of Class IE 120-volt Distribution Panel DP001 Energized from Alternate Power Supply.Caused by Less than Adequate Administrative Controls.Log Will Be utilized.W/901212 Ltr ML20044B1691990-07-0606 July 1990 LER 90-011-00:on 900612,chemical Technician Supervisor Discovered That No Sample Collected in Condenser Air Removal Sys Radiation Monitor Moisture Collection Tank. Caused by Inadequate procedure.W/900706 Ltr ML20043G2091990-06-14014 June 1990 LER 90-010-00:on 900515,determined That Leak & Contamination Test Interval for Some Radioactive Sources Exceeded Tech Specs.Caused by Insufficient Detail in Procedures.Test Program revised.W/900614 Ltr ML20043G5191990-06-14014 June 1990 LER 90-010-00:on 900515,unplanned Actuation of ESF Train C Standby Diesel Generator Occurred.Caused by Personnel Error. Training Bulletin Will Be Issued to Maint Personnel Re event.W/900613 Ltr ML20043G1791990-06-13013 June 1990 LER 90-009-00:on 900512,incorrect Wiring in Solid State Protection Sys Discovered.Caused by Inadvertent Installation of Extra Wire by Mfg.Extra Wire Removed & Sys Successfully tested.W/900613 Ltr ML20043G2101990-06-13013 June 1990 LER 90-009-00:on 900514,discovered That Printer for Toxic Gas Analyzer XE-9325 Was Not Updating & Surveillances for Toxic Gas Monitor XE-9325 Incorrectly Performed on 900511. Caused by Inadequate training.W/900613 Ltr ML20043G7681990-06-0808 June 1990 LER 90-008-00:on 900508,Tech Spec Required Shutdown Initiated Due to Primary Coolant Sys Leakage.Caused by High Cycle Fatigue Failure of Weld on Upstream Side of Drain Valve.Drain Valves replaced.W/900608 Ltr ML20043E7001990-06-0404 June 1990 LER 90-008-00:on 891007,Tech Spec Violation Occurred Due to Failure to Perform post-maint Testing.Caused by Incorrect Determination That No post-maint Testing Required.Personnel counseled.W/900604 Ltr ML20043C7401990-05-30030 May 1990 LER 90-007-00:on 900430,discovered That All Three Trains of ESFAS Placed in Test & Incapable of Actuating for Approx 35 Minutes.Caused by Inadequate Prerequisite Conditions in Maint Procedure.Procedure Being modified.W/900530 Ltr ML20043C4791990-05-29029 May 1990 LER 90-007-00:on 900426,standby Diesel Generator 22 Room High Sump Level Alarm Actuated in Control Room.Caused by Flooding & Inadequate Spec of Sealing & Testing Requirements.Seals on Removable Panels caulked.W/900529 Ltr ML20043B6611990-05-25025 May 1990 LER 90-006-00:on 900426,control Room Ventilation Sys Actuated to Recirculation Mode Due to High Level Trip of Vinyl Acetate Channel on Gas Analyzer.Caused by Failure of electro-mechanical Positioner.Part replaced.W/900525 Ltr ML20043A7811990-05-15015 May 1990 LER 90-005-00:on 900414,simultaneous Reactor & Turbine Trip Occurred Due to Failure of Main Turbine Electrohydraulic Control Line.Caused by Fatigue Stress of Weld.Valve Modified to Add anti-swirl Baffles & anti-rotation pins.W/900515 Ltr ML20042F2191990-05-0202 May 1990 LER 90-005-00:on 900329,feedwater Booster Pump 11 Tripped Upon Actuation of Ground Fault Relay & Standby Pump 13 Started But Did Not Deliver Sufficient Flow to Prevent Trip. Cause Not Found.Inlet Filters to Be cleaned.W/900502 Ltr ML20042E3561990-04-0505 April 1990 LER 89-015-01:on 890704,reactor Trip Occurred.Caused by Failure of Relay in Generator Breaker Trip Circuit.Relays in Generator Breaker Trip Circuits Replaced W/Correct Models & Checked to Ensure Proper rating.W/900405 Ltr ML20012C7211990-03-16016 March 1990 LER 90-003-00:on 900214,discovered That Train B Fuel Handling Bldg Exhaust Air Filter Outlet Damper Would Not Open.Caused by Wiring Error Due to Failure of Technicians to Follow Work Instructions.Technicians counseled.W/900316 Ltr ML20012B4381990-03-0101 March 1990 LER 90-002-00:on 900202,Train s Reactor Trip Breaker Opened, Initiating Turbine & Reactor Trip & Feedwater Isolation on Low Average RCS Temp.Cause Unknown.Universal Logic Cards Replaced & Monitoring Instruments installed.W/900301 Ltr ML20006E3781990-02-16016 February 1990 LER 90-001-00:on 900103,containment Ventilation Isolation Occurred Due to Loss of Power to Radiation Monitor Actuation Relay.Caused by Technician Lifting Power Lead. Technicians Trained & counseled.W/900216 Ltr ML20006E4001990-02-12012 February 1990 LER 90-001-00:on 900108,Train s Low Steam Line Pressure Blocking Switch Placed in Blocked Position,Causing Actuation of Safety Injection & ESF Sys.Caused by Lack of Instructions.Training Program modified.W/900212 Ltr ML20006D4231990-02-0202 February 1990 LER 90-002-00:on 900103,redundant Solenoid Valve Which Actuates Train C Feedwater Valve Failed.Caused by Excessive Particulate Buildup.Solenoids Cleaned & Hydraulic Oil Flushed & Filtered to Remove particulate.W/900202 Ltr ML20006D5591990-02-0202 February 1990 LER 89-023-01:on 891216,standby Diesel Generator 11 Failed Tech Spec Required Operability Test & Declared Inoperable. Caused by Contact Oxidation & Low Contact Pressure.Chiller Auxiliary Relay Cleaned & adjusted.W/900202 Ltr ML20006B4731990-01-25025 January 1990 LER 89-024-00:on 891226,required Sample from Safety Injection Accumulator 1C of Boron Concentration Not Taken. Caused by Insufficient Administrative Controls to Track Surveillance Tests.Bulletin Will Be issued.W/900125 Ltr ML20006B2551990-01-19019 January 1990 LER 89-022-00:on 891205,discovered That ASME Section XI Pressure Test of Train C of Component Cooling Water Sys Not Performed Prior to Returning Sys to Svc.Sys Inoperable from 890909-1206.Test Control Procedures revised.W/900119 Ltr ML20006B2221990-01-16016 January 1990 LER 89-023-00:on 891216,standby Diesel Generator 11 Failed Tech Spec Required Operability Test & Attempt to Secure Essential Chiller 12C Resulted in Trip.Caused by Failure of Voltage Regulator.Regulator Returned to mfg.W/900116 Ltr ML20005E2471989-12-29029 December 1989 LER 89-028-00:on 891130,control Room Ventilation Sys Actuated to Recirculation Mode as Result of Spurious Signal. Caused by Memory Error Causing Microprocessor to Energize Relay Incorrectly.Troubleshooting planned.W/891229 Ltr ML19332D7741989-11-24024 November 1989 LER 89-018-01:on 890922,discovered That Const Installation Procedure for Reg Guide 1.97,Rev 2 Instrumentation Did Not Include Details to Ensure Qualification Per 10CFR50.49 or IEEE 323-1974.Caused by Installation error.W/891124 Ltr ML19332C8661989-11-21021 November 1989 LER 89-027-00:on 891025,discovered That Closed Limit Switch on Main Turbine Throttle Valve 2 Disconnected.Caused by Failure of Limit Switch Linkage.Review to Be Performed of Limit Switch Linkage design.W/891122 Ltr 1994-05-02
[Table view] Category:RO)
MONTHYEARML20029D6321994-05-0202 May 1994 LER 94-002-01:on 940115,centrifugal Charging Pump 1A Discharge Bypass Valve Found in Open Position Contrary to Requirements of TS 3.1.2.3.Caused by hydro-pneumatic Transient.Valves Labeled W/Caution statements.W/940502 Ltr ML20029D6351994-04-27027 April 1994 LER 94-006-01:on 940214,reactor Manually Tripped Following Unanticipated Test Results.Caused by Mod Which Failed post- Mod Test.Test Terminated & Solid State Rod Control Sys Returned to Original Design configuration.W/940427 Ltr ML20029C6951994-04-18018 April 1994 LER 94-011-00:on 940310,safety Injection Actuation Was Received on Trains A,B & C.Cause Was Failure to Adhere to Procedure.Corrective Actions:Restored Cooling Shutdown & Removed Personnel from watchbill.W/940418 Ltr ML17352B2581994-03-25025 March 1994 LER 94-007-00:on 940224,station Procedure for Testing Reactor Trip Bypass Breakers Did Not Satisfy Ts.Caused by Inadequate Procedure Preparation & Review.Surveillance Procedure Enhancement Program underway.W/940325 Ltr ML20046C5471993-08-0606 August 1993 LER 93-018-00:on 930707,discovered Remote Position Indication Verification Test for SI Sys Accumulator Vent & Header Valves Had Not Been Performed in 2 Yrs Due to Change to IST plan.W/930806 Ltr ML20046C4901993-08-0505 August 1993 LER 93-019-00:on 930709,determined That TS Requirement of MSIV Was Not Met Due to Inadequate Design of Field Change to Testing Function of Solid State Protection Sys.Corrected Missing Jumpers & Overlap Testing discrepancy.W/930805 Ltr ML20046B1291993-07-29029 July 1993 LER 93-012-00:on 930614,lost Spent Fuel Pool Cooling for Approx 13 Hours Due to Insufficient Control Board Awareness. Design Change to Install Annunciator in Control Room to Inform of Loss of Spent Fuel cooling.W/930729 Ltr ML20046A6791993-07-21021 July 1993 LER 93-011-00:on 930401,pressurizer Safety Valve Setpoints Found Outside Required TS Tolerance.Caused by Setpoint Drift Due to Inherent Valve Characteristics.Mod of Test Procedures Underway ML20046A6511993-07-20020 July 1993 LER 93-017-01:on 930527,concluded That,Based on 930521 Determination,That Feedwater Isolation Bypass Valves Inoperable Since Pneumatic Positioners & Solenoids Remained in Svc Beyond Qualified Life.Control Scheme Modified ML20045J0281993-07-15015 July 1993 LER 93-016-01:on 930503,TS Violations Occurred Due to Circuitry for SG Power Operated Relief Valves & Post Accident Monitoring Instruments Being Inoperable.Replaced Missing Screws from Unit 1 QDPS.W/930715 Ltr ML20045H9171993-07-14014 July 1993 LER 93-008-01:on 930505,discovered That RHR Pump Suction MOV Had Not Been Environ Qualified Since 901129 Because Replacement of Drain T Not Completed.Drain T Missing from RH-0060B Replaced & Bulletin Issued to Maint Dept ML20045H9881993-07-13013 July 1993 LER 93-012-01:on 930405,TS Violation Occurred Due to Incorrect Settings of Several Molded Case Circuit Breakers. Reset Affected Unit 1 Breakers to Correct Settings. W/930713 Ltr ML20045E1531993-06-25025 June 1993 LER 93-017-00:on 930527,determined That Feedwater Isolation Bypass Valves Inoperable Since Pneumatic Positioner & Solenoids Remained in Svc Beyond Qualified Life.Caused by Incorrect Interpretation of Design Documents.Mod Underway ML20045E1491993-06-25025 June 1993 LER 93-010-00:on 930526,discovered That Screen Drive Coupling on Essential Cooling Water Traveling Screen 2A Damaged.Caused by Aging of Elastomeric Element.Couplings Replaced & Preventive Maint initiated.W/930625 Ltr ML20045B2731993-06-0909 June 1993 LER-93-016-00:on 930503,TS Violation Occured Due to Circuitry for SG PORVs & RCS Subcooling Monitor Being Inoperable.Caused by Less than Adequate Work Practices. Screws Missings from Qdps Replaced & Walkdown Performed ML20045A3831993-06-0404 June 1993 LER 93-008-00:on 930505,heat Removal Motor Operated Valve Inoperable in Excess of Allowable Outage Time.Caused by Failure to Recognize Condition.Condition Corrected by Replacing T Drain ML20044G4301993-05-25025 May 1993 LER 93-009-00:on 930426,Tech Spec Violation Occurred Due to Use of Inappropriate Ref Value Data for RHR Pump Inservice Test.Surveillance Procedures Revised to Include Appropriate Ref values.W/930525 Ltr ML20044F6281993-05-21021 May 1993 LER 93-015-00:on 930423,plant Personnel Determined That May 1990 Control Room Makeup & Cleanup Filtration Sys Svc Time Exceeded.Caused by Failure to Develop Run H Tracking Method. Run Times for Cleanup & Makeup Fans monitored.W/930521 Ltr ML20044F1321993-05-20020 May 1993 LER 93-009-01:on 930217,TS 3.0.3 Entered Due to Potentially Undersized Fuses in Ssps.Caused by Random Age Related Failure of Ssps Fuse.Fuses in Selected Equipment Replaced During Fuse & Breaker Field Verification Effort ML20044E0371993-05-14014 May 1993 LER 93-005-01:on 930214,control Room Operator Left CR Unmanned During Mode 4 Operation for 41 S.Caused by Inappropriate Action by Unit Supervisor.Event Will Be Included in Licensed Operator Requalification Training ML20024H2571991-05-24024 May 1991 LER 91-014-00:on 910420,erratic Containment Extended Range Pressure Channel Output Occurred.Caused by Bad Control Card. Weekly Channel Checks Performed,Control Card Replaced & Channel calibrated.W/910524 Ltr ML20024H2081991-05-22022 May 1991 LER 91-015-00:on 910422,train C AFW Pump Inadvertently Started Due to Failure of Led in Sequencer Test Circuitry. Faulty Led Replaced & Blocking Circuit Satisfactorily tested.W/910522 Ltr ML20029C1221991-03-15015 March 1991 LER 91-004-00:on 910215,loss of Offsite Power Actuation Occurred During Routine Maint.Caused by Lack of Attention to Work Performance Methods.Training Conducted for Maintenance personnel.W/910315 Ltr ML20029B0421991-02-25025 February 1991 LER 91-002-00:on 910126,automatic Actuation of Safety Injection Sys Occurred in One of Three Train C Trains.Caused by Inadequate Work Instructions for Maint Activity.Training Bulletin Issued & Supervisors counseled.W/910225 Ltr ML20024F7451990-12-12012 December 1990 LER 90-017-00:on 901104,discovered That Train a of Class IE 120-volt Distribution Panel DP001 Energized from Alternate Power Supply.Caused by Less than Adequate Administrative Controls.Log Will Be utilized.W/901212 Ltr ML20044B1691990-07-0606 July 1990 LER 90-011-00:on 900612,chemical Technician Supervisor Discovered That No Sample Collected in Condenser Air Removal Sys Radiation Monitor Moisture Collection Tank. Caused by Inadequate procedure.W/900706 Ltr ML20043G2091990-06-14014 June 1990 LER 90-010-00:on 900515,determined That Leak & Contamination Test Interval for Some Radioactive Sources Exceeded Tech Specs.Caused by Insufficient Detail in Procedures.Test Program revised.W/900614 Ltr ML20043G5191990-06-14014 June 1990 LER 90-010-00:on 900515,unplanned Actuation of ESF Train C Standby Diesel Generator Occurred.Caused by Personnel Error. Training Bulletin Will Be Issued to Maint Personnel Re event.W/900613 Ltr ML20043G1791990-06-13013 June 1990 LER 90-009-00:on 900512,incorrect Wiring in Solid State Protection Sys Discovered.Caused by Inadvertent Installation of Extra Wire by Mfg.Extra Wire Removed & Sys Successfully tested.W/900613 Ltr ML20043G2101990-06-13013 June 1990 LER 90-009-00:on 900514,discovered That Printer for Toxic Gas Analyzer XE-9325 Was Not Updating & Surveillances for Toxic Gas Monitor XE-9325 Incorrectly Performed on 900511. Caused by Inadequate training.W/900613 Ltr ML20043G7681990-06-0808 June 1990 LER 90-008-00:on 900508,Tech Spec Required Shutdown Initiated Due to Primary Coolant Sys Leakage.Caused by High Cycle Fatigue Failure of Weld on Upstream Side of Drain Valve.Drain Valves replaced.W/900608 Ltr ML20043E7001990-06-0404 June 1990 LER 90-008-00:on 891007,Tech Spec Violation Occurred Due to Failure to Perform post-maint Testing.Caused by Incorrect Determination That No post-maint Testing Required.Personnel counseled.W/900604 Ltr ML20043C7401990-05-30030 May 1990 LER 90-007-00:on 900430,discovered That All Three Trains of ESFAS Placed in Test & Incapable of Actuating for Approx 35 Minutes.Caused by Inadequate Prerequisite Conditions in Maint Procedure.Procedure Being modified.W/900530 Ltr ML20043C4791990-05-29029 May 1990 LER 90-007-00:on 900426,standby Diesel Generator 22 Room High Sump Level Alarm Actuated in Control Room.Caused by Flooding & Inadequate Spec of Sealing & Testing Requirements.Seals on Removable Panels caulked.W/900529 Ltr ML20043B6611990-05-25025 May 1990 LER 90-006-00:on 900426,control Room Ventilation Sys Actuated to Recirculation Mode Due to High Level Trip of Vinyl Acetate Channel on Gas Analyzer.Caused by Failure of electro-mechanical Positioner.Part replaced.W/900525 Ltr ML20043A7811990-05-15015 May 1990 LER 90-005-00:on 900414,simultaneous Reactor & Turbine Trip Occurred Due to Failure of Main Turbine Electrohydraulic Control Line.Caused by Fatigue Stress of Weld.Valve Modified to Add anti-swirl Baffles & anti-rotation pins.W/900515 Ltr ML20042F2191990-05-0202 May 1990 LER 90-005-00:on 900329,feedwater Booster Pump 11 Tripped Upon Actuation of Ground Fault Relay & Standby Pump 13 Started But Did Not Deliver Sufficient Flow to Prevent Trip. Cause Not Found.Inlet Filters to Be cleaned.W/900502 Ltr ML20042E3561990-04-0505 April 1990 LER 89-015-01:on 890704,reactor Trip Occurred.Caused by Failure of Relay in Generator Breaker Trip Circuit.Relays in Generator Breaker Trip Circuits Replaced W/Correct Models & Checked to Ensure Proper rating.W/900405 Ltr ML20012C7211990-03-16016 March 1990 LER 90-003-00:on 900214,discovered That Train B Fuel Handling Bldg Exhaust Air Filter Outlet Damper Would Not Open.Caused by Wiring Error Due to Failure of Technicians to Follow Work Instructions.Technicians counseled.W/900316 Ltr ML20012B4381990-03-0101 March 1990 LER 90-002-00:on 900202,Train s Reactor Trip Breaker Opened, Initiating Turbine & Reactor Trip & Feedwater Isolation on Low Average RCS Temp.Cause Unknown.Universal Logic Cards Replaced & Monitoring Instruments installed.W/900301 Ltr ML20006E3781990-02-16016 February 1990 LER 90-001-00:on 900103,containment Ventilation Isolation Occurred Due to Loss of Power to Radiation Monitor Actuation Relay.Caused by Technician Lifting Power Lead. Technicians Trained & counseled.W/900216 Ltr ML20006E4001990-02-12012 February 1990 LER 90-001-00:on 900108,Train s Low Steam Line Pressure Blocking Switch Placed in Blocked Position,Causing Actuation of Safety Injection & ESF Sys.Caused by Lack of Instructions.Training Program modified.W/900212 Ltr ML20006D4231990-02-0202 February 1990 LER 90-002-00:on 900103,redundant Solenoid Valve Which Actuates Train C Feedwater Valve Failed.Caused by Excessive Particulate Buildup.Solenoids Cleaned & Hydraulic Oil Flushed & Filtered to Remove particulate.W/900202 Ltr ML20006D5591990-02-0202 February 1990 LER 89-023-01:on 891216,standby Diesel Generator 11 Failed Tech Spec Required Operability Test & Declared Inoperable. Caused by Contact Oxidation & Low Contact Pressure.Chiller Auxiliary Relay Cleaned & adjusted.W/900202 Ltr ML20006B4731990-01-25025 January 1990 LER 89-024-00:on 891226,required Sample from Safety Injection Accumulator 1C of Boron Concentration Not Taken. Caused by Insufficient Administrative Controls to Track Surveillance Tests.Bulletin Will Be issued.W/900125 Ltr ML20006B2551990-01-19019 January 1990 LER 89-022-00:on 891205,discovered That ASME Section XI Pressure Test of Train C of Component Cooling Water Sys Not Performed Prior to Returning Sys to Svc.Sys Inoperable from 890909-1206.Test Control Procedures revised.W/900119 Ltr ML20006B2221990-01-16016 January 1990 LER 89-023-00:on 891216,standby Diesel Generator 11 Failed Tech Spec Required Operability Test & Attempt to Secure Essential Chiller 12C Resulted in Trip.Caused by Failure of Voltage Regulator.Regulator Returned to mfg.W/900116 Ltr ML20005E2471989-12-29029 December 1989 LER 89-028-00:on 891130,control Room Ventilation Sys Actuated to Recirculation Mode as Result of Spurious Signal. Caused by Memory Error Causing Microprocessor to Energize Relay Incorrectly.Troubleshooting planned.W/891229 Ltr ML19332D7741989-11-24024 November 1989 LER 89-018-01:on 890922,discovered That Const Installation Procedure for Reg Guide 1.97,Rev 2 Instrumentation Did Not Include Details to Ensure Qualification Per 10CFR50.49 or IEEE 323-1974.Caused by Installation error.W/891124 Ltr ML19332C8661989-11-21021 November 1989 LER 89-027-00:on 891025,discovered That Closed Limit Switch on Main Turbine Throttle Valve 2 Disconnected.Caused by Failure of Limit Switch Linkage.Review to Be Performed of Limit Switch Linkage design.W/891122 Ltr 1994-05-02
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217K9441999-10-15015 October 1999 SER Accepting Util Alternative Proposed Relief Request RR-ENG-2-4 for Second 10-year ISI Interval at Stp,Units 1 & 2 Pursuant to 10CFR50.55a(a)(3)(i) ML20217K9151999-10-15015 October 1999 SER Authorizing Util Relief Request RR-ENG-2-3 for Second 10-year ISI Interval of Stp,Units 1 & 2 Pursuant to 10CFR50.55a(a)(3)(i) NOC-AE-000676, Monthly Operating Repts for Sept 1999 for South Texas Project,Units 1 & 2.With1999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for South Texas Project,Units 1 & 2.With ML20217D0531999-09-30030 September 1999 Rev 1 to STP Electric Generating Station Unit 2 Cycle 7 Colr ML20217D0481999-09-30030 September 1999 Rev 1 to STP Electric Generating Station Unit 1 Cycle 9 Colr ML20211P8411999-09-0909 September 1999 Safety Evaluation Supporting Alternative Proposed by Licensee to Surface Exam to Perform Boroscopic VT-1 Visual Exam of Pump Casing Welds within Pump Pits for Welds Covered by Relief Request RR-ENG-24 ML20211P7811999-09-0909 September 1999 SER Approving Second 10-year Interval Inservice Insp Program Plan Relief Request RR-ENG-2-8 (to Use Code Case N-491-2) for South Texas Project,Units 1 & 2 ML20211Q6731999-09-0909 September 1999 Safety Evaluation Accepting First 10-yr Interval ISI Program Plan Request for Relief from ASME Code Case N-498 NOC-AE-000643, Monthly Operating Repts for Aug 1999 for South Texas Project,Units 1 & 2.With1999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for South Texas Project,Units 1 & 2.With ML20212E5191999-08-31031 August 1999 Rev 3 to SG-99-04-005, STP 1RE08 Outage Condition Monitoring Rept & Final Operational Assessment ML20211F4531999-08-24024 August 1999 Safety Evaluation Supporting Licensee Proposed Alternative to Defer Partial First Period Exams of flange-to-shell Weld to Third Period & Perform Required Ultrasonic Exams,Both Manual & Automated,During Third Period ML20211F5111999-08-23023 August 1999 Safety Evaluation Supporting Licensee Proposed Alternative Contained in Request for Relief RR-ENG-30 ML20210C9411999-07-31031 July 1999 Rev 1 to SG-99-07-002, South Tx,Unit 1 Cycle 9 Voltage- Based Repair Criteria 90-Day Rept, Jul 1999 ML20210R3631999-07-31031 July 1999 Monthly Operating Repts for July 1999 for South Tx Project, Units 1 & 2.With ML20210D9161999-07-23023 July 1999 Safety Evaluation Accepting Inservice Testing Relief Request RR-56 Re Component Cooling Water & Safety Injection Sys Containment Isolation Check Valve Closure Test Frequency ML20210D4821999-07-21021 July 1999 1RE08 ISI Summary Rept for Steam Generator Tubing of South Texas Project Electric Generating Station Unit 1 ML20210D4491999-07-21021 July 1999 Revised Chapters to Operations QA Plan, Including Rev 9 to Chapter 1.0, Organization & Rev 6 to Chapter 16.0, Independent Technical Review NOC-AE-000583, LER 99-S03-00:on 990619,failure to Revitalize Sdg Number 11 Was Noted.Caused by Failure to Communicate Status of Sdg. Subject Sdg Revitalized on 990619 & Licensee Will Develop Security Force Instruction Re Sdgs.With1999-07-15015 July 1999 LER 99-S03-00:on 990619,failure to Revitalize Sdg Number 11 Was Noted.Caused by Failure to Communicate Status of Sdg. Subject Sdg Revitalized on 990619 & Licensee Will Develop Security Force Instruction Re Sdgs.With ML20207H6361999-07-0808 July 1999 Safety Evaluation Approving 2nd 10 Yr Interval ISI Program Plan Request to Use ASME Section XI Code Case N-546 for Licenses NPF-76 & NPF-80,respectively ML20216D7481999-07-0707 July 1999 1RE08 ISI Summary Rept for Welds & Component Supports of STP Electric Generating Station,Unit 1 NOC-AE-000593, Monthly Operating Repts for June 1999 for Stp,Units 1 & 2. with1999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Stp,Units 1 & 2. with NOC-AE-000570, LER 99-S01-00:on 990527,discovered That Unescorted Access Had Been Inappropriately Granted.Caused by Failure to Follow Procedure.Util Verified That Individual Did Not Have Current Unescorted Access at STP or Any Other Util.With1999-06-28028 June 1999 LER 99-S01-00:on 990527,discovered That Unescorted Access Had Been Inappropriately Granted.Caused by Failure to Follow Procedure.Util Verified That Individual Did Not Have Current Unescorted Access at STP or Any Other Util.With ML20196G5821999-06-23023 June 1999 LER 99-S02-00:on 990601,failure to Maintain Positive Control of Vital Area Security Key Was Noted.Caused by Lack of Attention to Detail.Discussed Event with Operator Involved IAW Constructive Discipline Program ML20195J6871999-06-17017 June 1999 Safety Evaluation Supporting Proposed Alternative Contained in RR-ENG-2-5.Proposed Alternative Authorized Per 10CFR50.55a(a)(3)(i) for 2nd ISI Interval ML20196A2391999-06-15015 June 1999 Change QA-042 to Rev 13 of Operations QAP, Reflecting Current Organizational Alignment for South Texas Project & Culminating Organizational Realigment That Has Been Taking Place During Past Several Months NOC-AE-000563, Monthly Operating Repts for May 1999 for Stp,Units 1 & 2. with1999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Stp,Units 1 & 2. with ML20206U5411999-05-18018 May 1999 Non-proprietary Errata Pages for Rev 2,Addendum 1 to WCAP-13699, Laser Welded Sleeves for 3/4 Inch Diamete Tube Feedring Type & W Preheater SGs Generic Sleeving Rept ML20206A7721999-04-30030 April 1999 STP Electric Generating Station Unit 1 Cycle 9 Colr NOC-AE-000543, Monthly Operating Repts for Apr 1999 for Stp,Units 1 & 2. with1999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Stp,Units 1 & 2. with ML20205H0321999-03-31031 March 1999 Change QA-040 to Rev 13 of Operations QA Plan NOC-AE-000507, Monthly Operating Repts for Mar 1999 for Stp,Units 1 & 2. with1999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Stp,Units 1 & 2. with ML20205A3781999-03-22022 March 1999 STP Electric Generating Station Simulator Certification Four Yr Rept for Units 1 & 2 ML20204B2711999-03-15015 March 1999 Safety Evaluation Authorizing 990201 Request to Authorize Alternative to Regulations Per 10CFR50.55a(a)(3)(i) That Would Revise Start of Second 120-month IST Interval to No Later than 011201 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 NOC-AE-000468, Monthly Operating Repts for Feb 1999 for South Texas Project Electric Generating Station.With1999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for South Texas Project Electric Generating Station.With ML20207D1101999-02-24024 February 1999 Change QA-039 to Rev 13 of Operations QA Plan, for STP ML20203H8361999-02-17017 February 1999 Safety Evaluation Supporting Request for Relief from ASME Code Requirements for Class 3 Piping for Plant ML20202H9621999-02-0303 February 1999 SER Accepting Change to EALs Used in Classification of Emergency Conditions ML20202E8471999-01-31031 January 1999 2RE06 ISI Summary Rept for SG Tubing of STP Electric Generating Station,Unit 2 ML20216G2011999-01-31031 January 1999 City Public Svc of San Antonio Annual Rept 1998-1999 ML20199G5961999-01-31031 January 1999 Cycle 7 Voltage-Based Repair Criteria Rept for Jan 1999 ML20199K7711999-01-21021 January 1999 Safety Evaluation Accepting ISI Program Request for Relief for ASME Cose Repair Requirements for Code Class 3 Piping ML20199G8161999-01-19019 January 1999 SER Accepting Util 970707 Response to NRC 970509 RAI Re GL 92-08, Thermo-Lag 330-1 Fire Barriers. NRC Finds No Significant Safety Hazards Based on Application of Util Ampacity Derating Methodology ML20199H4981999-01-11011 January 1999 2RE06 ISI Summary Rept for Welds & Component Supports of Stp,Unit 2 ML20206Q3751999-01-0404 January 1999 2RE06 ISI Summary Rept for Sys Pressure Tests (Class 1 & 2) ML20206Q3721999-01-0404 January 1999 2RE06 ISI Summary Rept for Repairs & Replacements ML20216G2171998-12-31031 December 1998 Houston Industries 1998 Annual Rept. App a 1998 Financial Statements & Us Securities & Exchange Commission Form 10-K Encl NOC-AE-000403, Monthly Operating Repts for Dec 1998 for South Texas Project Unit 1 & 2.With1998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for South Texas Project Unit 1 & 2.With ML20216G1521998-12-31031 December 1998 Central & South West Corp 1998 Summary Annual Rept & Securities & Exchange Commission Form 10-K ML20198M3431998-12-28028 December 1998 SER Accepting Util Request for Relief from ASME Code Repair Requirements for ASME Code Class 3 Piping for South Texas Project,Unit 2 1999-09-09
[Table view] |
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NRC EORM 366 U.S. C%CLELD REGULATC3Y COMMISSION APPROVED BY OMB C~3. 3150-0S04 (5-92) EXPIRES 5/31/95 ESilMATED BURDEN PER RESPONSE 10 COMPLY WITH
" " ^ ' LL LICENSEE EVENT REPORT (LER) $AR0 CMMEN 5 R GARDING BURDEN ST MATE b THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLE AR REGUL ATORY COMMISSION, (See reverse for required ruber of digits / characters for each block) WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WAGHINGTON, DC 20503.
FACILITY WAME (1) DOCKET NUMBER (2) PAGE (3)
South Texas, Unit 1 05000 498 1 OF 8 TITLE (4) Extencion of FWIBV Positioner and Solenoid Equipment Beyond Qualif_ication Lifn OTHER FACIL ITIES INVOLVED (8)
EVENT DATE (5) IER NLMBER (6) REPORT DATE (7)
FACIL11Y NAME DOCKEi NUMBER SE N S MONTH DAY YEAR YEAR B
HONTH DAY YEAR South Texas, Unit 2 05000499 FA I M CKET " "
05 27 93 93 -- 017 --
00 06 25 93 0r0O OPERATING THlS um IS SusMimD mm TO THE HMMEUS OF 10 CW D (Check one or w e) W) 5 20.402(b) 20.405(c) 50. 73(a)(2)( i v) 73.71(b)
Ma)E (9)
PourR 2WaWO McW MaMW M e) g LEVEL (10) 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER x 50.73(a)(2)(i) 50. 73(a)(2)( vi t i )( A) (specify in 20.405(a)(1)(iii)
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20.405(a)(1)(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) 20.405(a)(1)(v) 50.73(a)(2)(iii) 50. 73(a)(2)( x) NRC Form 366A)
LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER (include Area Code)
Jairo Pinzon - Senior Engineer (512) 972 - 8027 COMPL E TE ONE LINE FOR EACH COMPONENT F AltVRE DESCRIRED IN THIS REPORT (13)
CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER g
X SJ CPOS V037 YES X SJ SOL A609 YES SLFPL E ME NT AL REPORT EXPECTfD (14) MONTH DAY VEAR EXPE CT ED YES(if yes, conplete EXPECTED SUBMISSION DATE). X NO ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)
On May 27, 1993, Unit 1 was in Mode 5 at 0% power and Unit 2 was defueled in a refueling outage. Plant personnel determined that the Feedwater Isolation Bypass Valves (FWIBVs) in both units were inoperable since the pneumatic positioner and solenoids had remained in service beyond their qualified life, which had been inappropriately extended to 40 years. STP personnel determined that Technical Specification 3.7.1.7 had been violated during various modes of operation since 1992. The inappropriate extension of the equipment qualification life of the FWIBV positioner and solenoids was the result of incorrectly interpreting design documents. Corrective actions include reviewing other safety-related valves with positioners for similar problems, reviewing other solenoid valves qualified for service in a harsh environment to determine if similar problems could exist, reviewing safety-related components which have been classified as non-safety to determine generic implications, and modifying the pneumatic control scheme of the FWIBV to ensure closure of the valves independent of the positioner upon de-energization of the safety-related solenoid valves.
l NRC m M 366 (5-92) 9307010186 930625 PDR ADOCK 05000499 S PDR ,
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NRC FORM 366A U.S. NUCLEAR REQJLAT O Y COMMISSI C APPROVED B7 OMB CD. 3150-0104 -
($.92} EXPIRE 5 $/31/95 ESilMATED BURDEN PER RESPONSE TO COMPLY WITH THl$
INFORMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS RFCARDING BURDEN ESTIMATE TO THE L'ICENSEE EVENT REPORT (LER) INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (31$0-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.
FACILITY NAMF (1) DOCKET NUMBER (2) LER NUMBER (61 PACE (3)
YEAR SEQUENTIAL REVISION 2 OF 8 South Texas, Unit 1 05000 498 93 -
017 -- 00 TEXT (if more space is reouired, use additional copies of NRC Form 366Al (17)
DESCRIPTION OF EVENT:
On May 27, 1993, Unit 1 was in B de 5 at 0% power and Unit 2 was defueled in a refueling outage. Plant pe. .el determined that the FWIBVs in both units were inoperable since the pm .ic positioner and solenoids had remained in service beyond their qual! A tife, which had been inappropriately extended to 40 years. STP personne2 determined that Technical Specification 3.7.1.7 had been violated during various modes of operation since 1992. Technical Specification 3.7.1.7 requires that each FWIBV be operable while in Modes 1, 2 and 3.
POSITIONERS The operability determination for the positioner event was based on a review of Seismic / Environment Qualification (EQ) reports and the valve manuf acturer's (Valtek) report. These qualification reports show that the positioner was qualified with the valve and meets the requirements for use as safety-related equipment. These reports also required the positioner sof t parts be replaced periodically. The current EQ document for the positioner indicates that it is a non-safety-related device and, therefore, requires no qualification.
This derating was based on a September 1986, evaluation concluding that the pneumatic positioners were non-safety. Further review of the plant design documents showed that the positioners do perform a safety function and, therefore, the EQ requirements should be maintained.
The EQ report for the positioners requires a replacement of sensitive parts every four years (based on maximum 6 continuous operating temperature of 300 F and a threshold radiation of 10 rads) to achieve a forty-year life. The replacement interval is based on the worst case effect (maximum operating temperature or radiation exposure) to the age-sensitive materials in - the positioner. Design criteria radiation dose for a postulated accident.in the Isolation Valve Cubicle is Jess than the threshold limit, which makes operating temperature the determining factor. Based on an assumed maximum continuous operating temperature less than 212 F, the EQ life for the FWIBV positioners is five years. Based on these design assumptions, the EQ replacement period for Unit 1 expired in 1992, thus making the FWIBV technically inoperable for the last 1.5 years. The Unit 2 FWIBV positioners i have not yet exceeded their five-year life. HL&P is continuing to evalunte the operability of the positioners based on exposure to actual operating conditions.
On May 21, 1993, service requests were written to install a modification to the pneumatic control scheme of the FWIBV to ensure closure of the valves, independent of the positioner, upon de-energization of the safety-related solenoid valves. Since the positioner would no longer be required to perform a safety function, the requirement for EQ was deleted.
l LER 93\L93017RO.U2 !
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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSICO APPROVED BY OMB NO. 3150-0104 (5-92) EI:PIRES 5/31/95 ESilMATED BURDEN PEC CESPONSE TO COMPLV WITH THl$
INFORMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE LICENSEE EVENT REPORT (LER) INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHlhCTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (31300104), OFFICE OF MANAGEMENT AND BUDGET, WASHINCTON, DC 20503.
FACILITY NAME (1) DOCKET N1MBER (2) l tFR NUMBER (67 PAGE (3)
TEAR SEQUENTIAL REVISION South Texas, Unit 1 05000 498 3 OF 8 93 -- 017 -- 00 YXT (if more space is reouired, use additional copies of NRC form 366A) (17)
DESCRIPTION OF EVENT: (Cont'd)
A five step plan was established to address the generic implication of the declassification of the FWIBVs safety-related positioners and solenoids. This plan included reviews of the classification of all Valtek valve positioners, positioners provided for safety-related valves, and Heating, Ventilating and Air Conditioning system dampers. This plan also provided for reviews of active parts declassified by use of Technical Evaluations for proper consideration of system / component operation, a sample of EQ packages . for proper consideration of system / component operation, and reviews of EQ for solenoids which are normally energized but were evaluated as normally de-energized.
This review resulted in identifying twelve additional valves per unit where failure of the positioner could cause the valve to be mispositioned. Further review revealed the valves are located in a mild environment and do not require periodic replacement. Other solenoids of the same model used with the FWIBVs were identified and action taken to replace them. These. additional solenoids were on the non-safety related Steam Generator Augmented Blowdown valves, which do not have a qualified life limitation.
SOLENOIDS The Equipment Qualification Calculation Package (EQCP) for the FWIBV safety-related solenoids was reviewed and questions were raised relating to the assumptions used in determining the qualified life. Calculation E ASCO, Revision 3, indicated that the safety-related solenoids are only .
energized during feedwater heatup and not during normal operation.resulting in a qualified life of forty years. Review of the logic drawings for.these s valves showed that there are three solenoids for each FWIBV. One non-Class r 1E solenoid is controlled by a main control board handswitch and is normally de-energized. The other two Class 1E solenoids are each controlled by a combination of the Main Feedwater Isolation Valve control switches and a Feedwater Isolation signal from the Solid State Protection System. A review of the design documents showed that these two safety-related solenoids are energized during normal plant operations. As a result of recalculating the life of the solenoids in the normally energized state using worst case design basis assumptions, the qualified life is 2.5 years. As a result, _the qualified life expired in December 1989 for Unit 1 and June 1991 for Unit 2.
HL&P is continuing to evaluate the operability of the FWIBV solenoids based a on exposure to actual operating conditions.
I LER-93\L93017RO.U1 l t
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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSI(D APPROVED BY OMB No. 3150-0104 (5-92) .
EXPIDES 5/31/95 ESTIMATED BURDEN PER DESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUES1: 50.0 HRS.
"8" """ EN "'"
L'ICENBEE EVENT REPORT (LER) E $1[o$ ".'A23 Rr'c$ p N AuActM BRANCH MN NT TEXT CONTINUATION 7714), u.S NuttEAR REculAToRY c0MMISsl0N, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK 8 0104),
(31.,0 OFFICE OF REDUCTION PROJECT MANAGEMENT AND DUDGET, WASHINGTON, DC 20503.
FACILITY NAME (1) DOCKET NtMBER (?) LFR NUMBER (61 PAGE (3)
SEQUENTIAL REVISION YEAR
"#8" "#8" South Texas, Unit 1 05000 498 4 OF 8 93 -- 017 -- 00 TEXY (If more space is reovired, use additional copies of NRC Form 366Al (17)
DESCRIPTION OF EVENT: (Cont'd)
Other solenoid valves qualified for service in a harsh environment were reviewed to determine if the same condition could 9xist. The review' included ASCO, Valcor and Target Rock solenoids. This review resulted in a reduction in qualified life for the Preheater Bypass valves and the Main Steam Bypass valves ASCO solenoids. Although their qualified lives have been reduced, they have not yet expired as had the FWIBV solenoids and positioners.
CAUSE OF EVENT:
In both cases, the qualified life extensions of the FWIBV positioners and solenoid valves were the result of incorrectly interpreting design documents.
Plant Operations procedures and discussions between Instrumentation & Control personnel and Design Engineering EQ personnel were used to determine the function of the positioner and solenoids.
ANALYSIS OF EVENT:
The events pertaining to the extension of the FWIBVs positioner and solenoid valve EQ lives are reportable pursuant to 10CFR50.73 (a) (2) (i) (B) . This event represents an operation or condition prohibited by Technical Specification 3.7.1.7. Although the Units were not operated with FWIBVs open, failure of the FWIBV positioners or solenoid could result in t's FWIBVs remaining open.
The following accidents are impacted:
Steam Generator Tube Rupture (SGTR)
The prevalent concern with a SGTR (UFSAR section 15.6.3) is a release of radiation. There is no single failure coincident with a SGTR which involves a dose release path through the FWIBVs. By assuming a single failure of the check valve between a stuck open FWIBV and the Steam Generator, a dose release path could only be provided by a coincident feedwater line break. _However, considering a SGTR coincident with a loss of feedwater piping is beyond the design basis of the plant.
Also of concern for a SGTR is the Steam Generator overfill analysis.-Open FWIBVs may provide additional flow to the Steam Generators in addition to Auxiliary Feedwater (AFW) flow. Failure of the FWIBVs to close has no effect on feedwater system safety function as discussed in the Main Feedwater Failure '
Modes & Effects Analysis (FMEA) (UFSAR Table 10.4-8). The FMEA states that !
failure of the FWIBVs and Feedwater Isolation Valves to close is backed up by l closure of the feedwater flow control valves. Also, both the Steam Generator Feedwater Pumps (SGFPs) and the Start-up SGFPs trip, ef fectively reducing j feedwater flow to the affected Steam Generator. ;
l LER-93\L93017RO.u2
NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSICD APPROVED BY OMB 110. 3150-0104 (5 92) .
EXPICES 5/31/95
, ESTIMATED BURDEN PER RESPONSE TO COMPLV WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESilMATE TO THE LICENBEE EVENT REPORT (LER) INFORMATION AND REr0RDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), U.S. . NUCLEAR REGULATORY COMMISSION, WASHlWGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (31$00104), OFFICE OF MANAGEMENT AND BLOCET, WASHINGTON, DC 20503.
FACit1TY NAME (1) DOCKET NLMBER (2) LER NLMBER (61 PAGF (3)
YEAR SEQUENTIAL REVISION South Texas, Unit 1 05000 498 5 OF 8 93 -- 017 -- 00 TEXT (If more space is required. use additional copies of NRC Form 3f4A) (17)
ANALYSIS OF EVENT: (Cont'd) feedwater System Pipe Break A Feedwater System Pipe break (UFSAR section 15.2.8) is defined as a break in a feedwater line large enough to prevent the addition of sufficient feedwater to the Steam Generators to maintain shell-side fluid inventory in the Steam Generators. A break upstream of the feedwater line check valve is bounded by a Loss of Normal Feedwater Flow (UFSAR section 15.2.7). If the break is postulated between the check valve and the Steam Generator, Steam Generator fluid as well as feedwater flow may be discharged through the break. The limiting single failure for the current analysis is loss of safety Train A resulting in a loss of AFW to Steam Generators A'and D. With the failed feedwater line in either Steam Generator B or C, one Steam Generator would be available for Reactor Coolant System cooling.
If the break occurs concurrent with a single failure of the check valve _in an unaffected loop, some AFW flow may be lost to two Steam Generators: (i) the Steam Generator in the loop with the failed check valve (through the check valve and the FWIBV), and (ii) the Steam Generator in the loop in which the break occurs. The flow lost through the FWIBV would be limited by closure of the Feedwater flow control valves as discussed in the Main Feedwater FMEA.
However, there would still be AFW flow to two intact Steam Generators, which is bounded by the current analysis.
Loss of Norma _1 Feedwater Flow For a Loss of Normal Feedwater flow accident (UFSAR section 15.2.7), the limiting case is a single failure loss of Safety Train A resulting in a loss of AFW flow to Steam Generators A and D. In this instance, the check valves between the Steam Generators and the FWIBVs would prevent loss of Steam Generator inventory through the misaligned FWIBVs. As discussed in the SGTR analysis, there is no credible f ailure coincident with the single failure ol' one of the check valves which could result in loss of AFW inventory back through the FWIBVs.
Small BJ_eak Loss of Coolinct Accident The limiting single failure for a Small Break Loss of Cooling Accident (LOCA)
(UFSAR section 15. 6. 5) is a loss of safety Train A resulting in a loss of AFW flow to Steam Generators A and D. The same discussion for the Loss of Normal Feedwater Flow accident above is applicable here; taking the check valve failing as the single f ailure is bounded by the loss of AFW to Steam Generator 1 A and D. l LER 93\L93017RO.U2
NRC FORM 366A U.S. NUCLEAR REGULATOY COMMISSIC APPROVED BY OMB NO. 3150-0104 (5-92) .
ERP!3ES 5/31/95 ESitMATED BURDEN PEQ SESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS, FORWARD COMMENTS REGARDING BURDEN ESilMATE TO THE LICENSEE EVENT REPORT (LER) INFORMATION AND RECORDS MANAGEMENI BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, TEXT CONTINUATION WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150 0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503, FACillTY NAME (1) DOCKET NtNBER (2) 1ER WlMBER (61 PAGE (3)
SEQUENTIAL REVISION YEAR
"#"" "#8" South Texas, Unit 1 05000 498 6 OF 8 93 -- 017 -- 00 TEXT (if more space is reauired use additional copies of Nec Form 366A) (17)
ANALYSIS OF EVENT: (Cont'd) liain Steam Line Brea}: (MSLB)
In the event of a MSLB accident, significant feedwater flow through the open FWIBVs would not occur because of feedwater flow control valve closure and tripping of both the SGFPs and the Start-up SGFPs as discussed above.
Based on the above considerations, safety significance from postulated misalignment of FWIBVs, is very low.
CORRECTIVE ACTIONS:
- 1. The Preventive Maintenance (PM) activities for EQ replacement for the FWIBV solenoids have been reactivated.
- 2. A review of other safety-related valves with positioners was performed to identify similar concerns. A group of twelve Chilled Water valves was identified with a similar configuration; however, these valves are not located in a harsh environment and no periodic parts replacement is required to maintain the qualification. Further investigation revealed that the EQ of the Chilled Water valve positioners have not been altered.
- 3. A modification to revise the pneumatic control scheme'of the FWIBVs to ensure closure of the valves independent of the positioner upon de-onergization of the safety-related solenoid valves, has been developed.
This modification has been implemented in Unit 1 and will be implemented by the end of the current refueling outage in Unit 2.
- 4. A review of other solenoid valves qualified for service in a harsh environment was performed to determine if a similar problem existed. This review included ASCO, Valcor and Target Rock solenoid valves. This review resulted in a reduction in qualified life for the Preheater Bypass valve and Main Steam Bypass valve ASCO solenoids. Although reduced, their qualified lives reduced, have not yet expired as had the FWIBV solenoids and positioners. EQ PM activities will be developed to ensure replacement prior to expiration. These PM activities will be developed by August 18, 1993.
LER-93\L93017RD.U2
NRC FC:n 366A U.S. NUCLEAR REGULA1C2Y COMMISSICC APPROVED BT CMR No. 3150-0104 (5-92) .
EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESilMATE TO THE LICENSEE EVENT REPORT (LER) INFORMAfion Ano REcokDS MANAGEMENT 6 RANCH (MNBB TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555 0001 AND TO THE PAPERWORK REDUCYlON PROJECT (31$0-0104), OFFICE OF MANAGEMENT AND BUDGET. WASHINGTON, DC 20503.
FACit!TY NAME (1) DOCKFT NtmarR (?) trR NUMBER (61 PAGE (3)
SEQUENTIAL REVISION YEAR South Texas, Unit 1 05000 498 7 OF 8 93 -- 017 -- 00 TEXT (if more space is rew ired, use additional copies of NRC Form 366A) (17)
CORRECTIVE ACTIONS: (Cont'd)
- 5. Information regarding the positioner and solenoid events will be provided to Engineering personnel as lessons learned. In addition, Engineering personnel will be sensitized on the need for attention to detail with regard to EQ and verifying assumptions. This action will be completed by July 9, 1993.
- 6. To address generic implications, a five-step review process was developed to evaluate the part reclassifications and EQ issues indicated as a result of this LER. This review has not resulted in any additional plant safety issues. As a result of this review, the sample scope has been expanded.
This additional review will be completed by July 21, 1993.- Based on this additional review, corrective actions and recurrence control measures will be developed as necessary, bDDITIONAL INFORMATION:
The FWIBV positioners are manufactured by Valtek and are model number 80R.
The FWIBV solenoids are manufactured by ASCO and are model numbers 206-832-4VF, NP831655E, and NP8321A2E/A6E.
During the past two years, two LERs have been submitted to the NRC which were related to Equipment / Environmental Qualification problems. These LERs are as follows:
o Unit 2 LER 93-008 regarding a Technical Specification violation due to a failure to maintain Environmental Qualification of a Residual Heat Removal Motor Operated Valve.
o Unit 1 LER 93-017 regarding a failure of an Essential Cooling Water traveling screen drive coupling.
The following information is with regard to an event that was discovered on ;
April 21, 1993, in which the FWIBV was thought to be open when a Maintenance ,
technician observed pointer movement on the stem clamp during maintenance work l on the FWIBV. The technician believed that since the pointer movement on the l stem clamp was sudden, the valve stem had moved and the valve had been partially open. This was thought to be reportable because the plant had operated in various modes contrary to Technical Specifications. The valve was
. thought to be open since April 25, 1992. Further investigation determined that the valve, in fact, was closed as required during this time period.
LER-93\L93017RO.U2
o ECFORM366A U.S. NUCLEAR REGJLATORY COMMISSICC APPROVED BY CMB NO. 3150-0104 (5-92) .
EXPIRES 5/31/95 EST! MATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESilMATE TO THE
. $ICENBEE EVENT REPORT (LER) INroRMAT!ow AND RECORDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMIS$10N, WASHINGTON, DC 20555 0001, AND TO THE PAPERWORK REDUCT10W PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON. DC 20503.
FACILITY NAME (1) DOCKET NUMBER (2) LER NUMR[R (65- PAGE (3)
SEQUENTIAL REVISION YEAR South Texas, Unit 1 05000 498 8 OF 8 93 -- 017 -- 00 TEXT (if more srmee is reo; ired. use additional cordes of NRC Form 366A) (17)
ADDITIONAL INFORMATION: (Cont'd)
.On May 22, 1993, Fisher Service Company performed a series of diagnostic tests to determine the overall operating condition of the valve. The tests verified that the valve stroke, packing friction, and seat load were within specifications, but did indicate minor resistance in the upper portion of the stroke. This resistance did not prevent or hinder the valve from stroking.
Fisher felt that the resistance could be from galling in the stem guide area or packing material buildup on the stem of the valve. The actuator spring rate, total travel, and bench settings were within specifications. On May 25, 1993, the FWIBV was disassembled and an inspection performed by Engineering and Maintenance personnel revealed signs of normal wear except for thread damage on the upper 5/8 in. of the actuator stem and valve plug stem. There were no indications of any sticking or binding in the valve actuator or body.
On May 26, 1993 the Valtek vendor was brought in to inspect the valve.
Valtek's inspection concurred with HL&P's finding.
HL&P has analyzed Fisher's diagnostic test and Valtek's report. The review did not lead to any conclusive evidence that the valve was opened during nornal operations or that binding occurred which prevented closure.
Therefore, HL&P has determined that the valve was not open and this event is not reportable. The basis for the conclusion are as follows:
o The I&C technician could not be certain that he witnessed valve stem movement.
o Valve travel is limited by plug motion between seat and backseat which was measured to be 1~ . 67 2 inches. The limit switch settings were found approximately 1.5 inches apart, indicating that the valve had been stroking fully.
o No physical evidence was found upon inspection of the valve components which could have caused or indicated mechanical binding of the valve, o Fisher's diagnostic testing revealed normal valve _ operation with relatively little packing drag, o The discovered thread damage on the actuator stem and valve plug stem at the point of overlap suggests that when the valve stem clamp was loosened 1 I
for maintenance, the valve actuator stem moved downward while the valve plug stem was stationary due to the valve plug being seated. This also l accounts for the observed pointer movement. I lek-93\L93017RO.U2 l