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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20024J3271994-10-0303 October 1994 LER 94-020-00:on 940901,discovered That Elapsed Time Meters Installed in Essential CR HVAC & SGTS Due to Defective Procedures at Time of Installation.Crefs & SGTS Declared inoperable.W/941003 Ltr ML20029E5871994-05-13013 May 1994 LER 94-007-00:on 940413,HPCI Sys Declared Inoperable.Caused by Lack of Sufficient Restraint on Tubing.Corrective Action: Tubing Placed Back on Fitting & Clamp Was Retensioned.W/ 940513 Ltr ML20029C7211994-04-22022 April 1994 LER 92-020-00:on 920130,containment Level Instruments Were Removed & re-installed Without Being Declared Inoperable. Caused by Personnel Failure to Follow Procedures.Operators retrained.W/940422 Ltr ML20046B4881993-07-30030 July 1993 LER 93-028-00:on 930630,two Potentially Valves Were Inoperable Due to Inadequate Design of Valve Operators by Manufacturer.Modified Valve operators.W/930730 Ltr ML20046A3001993-07-21021 July 1993 LER 93-010-01:on 930331 & 0621,RPS Bus B Deenergized Due to Defective Under Frequency (Uf) Trip Unit Resulting in Unplanned Actuations of Several Esfs.Action Initiated to Permanently Remove Uf feature.W/930721 Ltr ML20045H6011993-07-13013 July 1993 LER 93-025-00:on 930618,determined That Hydrogen/Oxygen Monitoring Sys May Not Effectively Perform post-accident Monitoring Functions.Caused by Insufficient Slope in Lines.Filters Removed & Pump Internals Upgraded ML20045H6051993-07-13013 July 1993 LER 93-026-00:on 930618,discovered That Hydrostatic Tests of Essential Portions of Svc Water & Reactor Equipment Cooling Sys Not Performed Once Per 10 Year ISI Interval. Inclusion of Essential Sys Portion Being Reevaluated ML20045H6071993-07-13013 July 1993 LER 93-027-00:on 930308,standby Gas Treatment Sys Unable to Establish & Maintain Reactor Bldg Pressure + or - 0.25 Inches Water Gauge Under Calm Wind Conditions.Evaluation of Secondary Containment Operability in Progress ML20045E9861993-06-28028 June 1993 LER 93-023-00:on 930528,fuel Assemblies Loaded Into Reactor Core Without Control Rods Fully Inserted,In Violation of TS 3.10.A.2.Caused by Need to Reposition Fuel Support Piece. Training Will Be revised.W/930628 Ltr ML20045E6561993-06-28028 June 1993 LER 93-024-00:on 930527,discovered That Testing of Four Reactor Vessel Low Water Level RPS Sensors Not Completed as Scheduled.Caused by Personnel Error.Stroke Testing Suspended & Surveillance Testing completed.W/930628 Ltr ML20045B4701993-06-11011 June 1993 LER 93-021-00:on 930611,determined That RB Ventilation Exhaust Inboard Isolation Valve HV-AOV-261AV Inoperable & Open Due to Personnel Error.Subj Valve Manually Closed. Proposed Change to TS Will Be submitted.W/930611 Ltr ML20045A5431993-06-0505 June 1993 LER 93-020-00:on 930507,determined That H2/O2 Sys Not Leak Tested to Verify Primary Containment Integrity During Testing of Sys.Caused by Failure to Have Administrative Controls in Place.Pressure Testing conducted.W/930605 Ltr ML20045A4331993-06-0101 June 1993 LER 93-SO1-00:on 930429,discoverd That Individual Had Tested Positive for Drugs at Another Facility on 930226.Employer Had Not Previously Been Notified.Approved Contractor Access Authorization Program suspended.W/930601 Ltr ML20045A4611993-06-0101 June 1993 LER 93-019-00:on 930501,nonconservative Testing Methodology Discovered During LLRT Due to Nonconservative Interpretation of Info Supplied by Valve Mfg.Testing Conducted for Valves Not Previously tested.W/930601 Ltr ML20044G8011993-05-28028 May 1993 LER 93-017-00:on 930428,discovered That Hourly Fire Watch Patrol for RB Per TS Had Not Been Performed.Caused by Personnel Error.Review of Fire Watch Patrol Implementation Process Will Be conducted.W/930528 Ltr ML20044E6301993-05-20020 May 1993 LER 93-015-00:on 930420,design Discrepancy in HPCI Sys Identified.Caused by Design Deficiency in Original Design. Mods Will Be Made to Startup from Current Refueling Outage to Correct Design discrepancy.W/930520 Ltr ML20044D8211993-05-17017 May 1993 LER 93-014-00:on 930316,small through-wall Leak Developed on High Pressure Side of SW Throttle Valve.Caused by Inadequate Valve Design.Frequency of Visual Insp of Valve Internals Will Be Increased to Once Per cycle.W/930517 Ltr ML20044D6511993-05-15015 May 1993 LER 93-013-00:on 930415,determined That as-found Setpoint for Seven SRVs Not within TS Limit.Caused by Lift Setpoint Discrepancies of Srvs.Review of Setpoint Data Will Be performed.W/930515 Ltr ML20044D5341993-05-14014 May 1993 LER 93-012-00:on 930414,violation of Primary Containment Integrity Occurred.Caused by Personnel Error.Procedure Change Being Made to Eliminate Test Return Line Venting When Primary Containment Integrity required.W/930514 Ltr ML20044D2041993-05-12012 May 1993 LER 93-011-00:on 930308,max Differential Pressure Between Reactor Bldg & External Environ of -0.22-inches Water Gauge Exceeded TS Required Min.Caused by Lack of Loop Seal on Rupture Seal Drain Line.Seals replaced.W/930512 Ltr ML20024G7421991-04-23023 April 1991 LER 91-002-00:on 910324,RWCU Occurred Due to High Sys Temp During Plant Cooldown.Caused by Failed Temp Indication & Potential Equipment Failure.Failed Thermocouple & Temp Switch Replaced & calibr.W/910423 Ltr ML20043D2311990-05-30030 May 1990 LER 90-005-00:on 900430,reactor Protection Sys B Motor Generator Set Output Breaker Tripped.Caused by Equipment Malfunction & Preventive Maint Program Deficiency.Sys Restored to Pretrip Operational state.W/900530 Ltr ML20042G9411990-05-10010 May 1990 LER 90-004-00:on 900413,ESF Group Isolations & Diesel Generator Starts Occurred Due to Equipment Malfunction & Personnel Error.Equipment Repaired,Manual Disconnect Operating Location Labeled & Personnel trained.W/900510 Ltr ML20011F1321990-02-23023 February 1990 LER 90-001-00:on 900124,outboard Steam Supply Line Isolation Valve Unexpectedly Closed During Surveillance Testing,Causing Isolation of HPCI Sys.Caused by Procedural Inadequacy.Test Procedure Will Be upgraded.W/900223 Ltr ML20005E3331989-12-26026 December 1989 LER 89-026-00:on 891125,reactor Scram Occurred Due to Closure of Outboard Msivs.Caused by post-filter Media Ignition by Hot Air or Particles from Dryer.Air Dryer B Disassembled & inspected.W/891226 Ltr ML19332F1191989-12-0707 December 1989 LER 88-016-02:on 880517,pipe Stress Analyses Revealed That Resultant Stresses for Five Piping Segments/Components Exceed Plant Design Basis.Caused by Support Design Problems. Long-term Corrective Program implemented.W/891207 Ltr ML19325E2201989-10-27027 October 1989 LER 89-025-00:on 890928,main Turbine Trip Occurred,Followed Immediately by Reactor Scram.Caused by Spurious Actuation of Level Switch Due to Equipment Vibration.Plant Stabilized & Temporary Instruction Re Pump Shifting issued.W/891027 Ltr ML20024C3571983-06-28028 June 1983 LER 83-008/03L-0:on 830530,HFA Relay 9-17-16A K6B Contacts Failed to Open.Cause Not Determined.Relay Coil Replaced. Systematic Replacement of All Relays within 4-yr Period planned.w/830628 Ltr ML20028F0921983-01-20020 January 1983 LER 82-025/03L-0:on 821222,coil of Reactor Protection Relay 915-5AK8C Overheated.Relay Did Not Fail.Cause Undetermined. Relay Replaced & Proper Operation Verified ML20028F0781983-01-20020 January 1983 LER 82-024/03L-0:on 821221,pressure Switch RHR-PS-120A Setpoint Found Outside Range Specified in Tech Specs.Caused by Failed Diaphragm.Pressure Switch Adjusted & Subsequent Testing Showed Nonrepeatable Trip Point.Switch Replaced ML20028B4671982-11-22022 November 1982 LER 82-022/03L-0:on 821025,RHR Time Delay Relay 10A-K45A Failed to Operate within Required Time Limits.Caused by Setpoint Being Set Too Conservatively.Relay Readjusted & Correct Operation Verified ML20028B4661982-11-19019 November 1982 LER 82-021/03L-0:on 821023,relay 917-16A-K44B Failed to Open Contacts When de-energized.Cause Not Determined.Relay Replaced & Correct Operation Verified.Monitoring Program Implemented to Determine Need for Generic Replacement ML20052G5321982-05-0606 May 1982 LER 82-008/03L-0:on 820415,during Diagnostic Testing of Mechanical Snubbers,Model PSA-10 SN/544 Snubber Exceeded Specified Acceleration Rate.Caused by Improper Installation of Clutch Spring.Snubber Sent to Manufactures for Repair ML20052B4041982-04-22022 April 1982 LER 82-007/03L-0:on 820324,differential Pressure Between Drywell & Suppression Chamber Reduced Below Tech Spec Limits During RHR Test Mode Operation.Caused by Nitrogen Flow from Drywell to Suppression Chamber.Return Piping to Be Modified ML20052A3561982-04-21021 April 1982 LER 82-006/03L-0:on 820322,while Inerting Drywell,Ductwork Between Primary Containment & Reactor Bldg Ventilation Found Failed in Several Places,Preventing Oxygen Concentration & Differential Pressure from Being Established ML20050B2101982-03-19019 March 1982 LER 82-005/03L-0:on 820221,MSIV-86A Found to Have Closing Time Faster than Tech Spec.Cause Unknown.Closing Time Adjusted & Control Valve Locked Into Required Position ML20041F8271982-03-0505 March 1982 LER 82-004/03L-0:on 820109,during Planned Power Reduction, Min Critical Power Ratio Was Below Operating Limit W/O Initiation of Corrective Actions Required by Tech Specs. Caused by Personnel Error.Procedures Will Be Revised ML20041C4151982-02-18018 February 1982 LER 81-003/03L-1:on 810223,valve RHR-MO-26B Motor Current Increased & Remained High When Valve Reached Closed Position.Valve Motor Breaker Manually Tripped & Valve Declared Inoperable.Caused by Failure of Brake Coil ML20041C3881982-02-17017 February 1982 LER 82-003/03L-0:on 820126,overload Alarm Condition Received While Closing Valve RHR-MO-26B,caused by Motor Brake Coil Failing to Release.New Motor & Brake Installed & Tested Satisfactorily ML20041C3741982-02-17017 February 1982 LER 82-002/03L-0:on 820121,during Routine Surveillance Testing NBI-LIS-101A Found to Trip at Lower than Tech Spec Limits.Caused by Barton Model 288 Switch Actuating at Random Positions.Switch Replaced ML20041C3871982-02-17017 February 1982 LER 82-001/03L-0:on 820122,reactor Vessel Level Switch NBI-LIS-72C Failed to Trip at Tech Spec Setpoint.Caused by Misalignment of Switch Mechanism.New Switch Calibr & Installed ML20040D3491982-01-20020 January 1982 LER 81-026/03L-0:on 811223,switches NBI-LIS-01A & NBI-LIS- 101B Found Set at Level Lower That Tech Spec Limits.Caused by Setpoint Drift.Switches Returned to Correct Setpoints. Instrument Drift to Be Closely Monitored ML20040D9261982-01-0505 January 1982 LER 81-025/04T-0:on 811224,during Full Power,Discharge Was Made from Floor Drain Sample Tank W/O Adequate Sampling & Analysis of Batch.Caused by Personnel Error.Liquid Discharge Procedures Being Revised.Personnel Reprimanded ML20038C5321981-12-0303 December 1981 LER 81-024/03L-0:on 811106,safety Relief Valve 71-D Failed to Close After Test.Caused by Failure of Solenoid Plunger to Drop Out When Solenoid de-energized.Solenoid Replaced ML20010G0961981-08-25025 August 1981 LER 81-020/03L-0: on 810728, During Procedure Returning Diesel Generator 1 to Svc After Flexible Fuel Line Leak, Control Air Line Fitting Failed Causing Generator to Shut Down. Caused by Broken Air Line Due to Crimped Ferrule ML20010F9881981-08-25025 August 1981 LER 81-019/03L-0:on 810728,during Surveillance to Prove Operability of Diesel Generator 1,fuel Supply Hose Developed Leak.Caused by Excessive Localized Flexure & Vibration. Hose Replaced ML20010G2661981-08-25025 August 1981 LER 81-021/03L-0:on 810728,during Performance of Surveillance Procedure on Diesel Generator 2,injection Line Failed.Caused by Metal Fatigue & Vibration.Component Replaced ML20010A1391981-07-22022 July 1981 LER 81-018/03L-0:on 810625,pressure Switch NBI-PS-52A Found W/Trip Point Less Conservative than Tech Spec.Apparently Caused by Setpoint Drift.Switch Readjusted.Setpoints for Switches Reset ML20010A1671981-07-13013 July 1981 LER 81-017/03L-0:on 810613,reactor Core Isolation Cooling Sys Steam Supply Valve RCIC-MOV-M016 Failed to Open.Caused by Improperly Wired Motor Operator Circuit.Jumper Installed ML20010A5391981-07-0909 July 1981 LER 81-016/03L-0:on 810610,core Thermal Power Calculation Performed by Process Computer Found Incorrect Due to Incorrect Feedwater Flow Value in Computer.Caused by Personnel Error in Changing Conversion Coefficient 1994-05-13
[Table view] Category:RO)
MONTHYEARML20024J3271994-10-0303 October 1994 LER 94-020-00:on 940901,discovered That Elapsed Time Meters Installed in Essential CR HVAC & SGTS Due to Defective Procedures at Time of Installation.Crefs & SGTS Declared inoperable.W/941003 Ltr ML20029E5871994-05-13013 May 1994 LER 94-007-00:on 940413,HPCI Sys Declared Inoperable.Caused by Lack of Sufficient Restraint on Tubing.Corrective Action: Tubing Placed Back on Fitting & Clamp Was Retensioned.W/ 940513 Ltr ML20029C7211994-04-22022 April 1994 LER 92-020-00:on 920130,containment Level Instruments Were Removed & re-installed Without Being Declared Inoperable. Caused by Personnel Failure to Follow Procedures.Operators retrained.W/940422 Ltr ML20046B4881993-07-30030 July 1993 LER 93-028-00:on 930630,two Potentially Valves Were Inoperable Due to Inadequate Design of Valve Operators by Manufacturer.Modified Valve operators.W/930730 Ltr ML20046A3001993-07-21021 July 1993 LER 93-010-01:on 930331 & 0621,RPS Bus B Deenergized Due to Defective Under Frequency (Uf) Trip Unit Resulting in Unplanned Actuations of Several Esfs.Action Initiated to Permanently Remove Uf feature.W/930721 Ltr ML20045H6011993-07-13013 July 1993 LER 93-025-00:on 930618,determined That Hydrogen/Oxygen Monitoring Sys May Not Effectively Perform post-accident Monitoring Functions.Caused by Insufficient Slope in Lines.Filters Removed & Pump Internals Upgraded ML20045H6051993-07-13013 July 1993 LER 93-026-00:on 930618,discovered That Hydrostatic Tests of Essential Portions of Svc Water & Reactor Equipment Cooling Sys Not Performed Once Per 10 Year ISI Interval. Inclusion of Essential Sys Portion Being Reevaluated ML20045H6071993-07-13013 July 1993 LER 93-027-00:on 930308,standby Gas Treatment Sys Unable to Establish & Maintain Reactor Bldg Pressure + or - 0.25 Inches Water Gauge Under Calm Wind Conditions.Evaluation of Secondary Containment Operability in Progress ML20045E9861993-06-28028 June 1993 LER 93-023-00:on 930528,fuel Assemblies Loaded Into Reactor Core Without Control Rods Fully Inserted,In Violation of TS 3.10.A.2.Caused by Need to Reposition Fuel Support Piece. Training Will Be revised.W/930628 Ltr ML20045E6561993-06-28028 June 1993 LER 93-024-00:on 930527,discovered That Testing of Four Reactor Vessel Low Water Level RPS Sensors Not Completed as Scheduled.Caused by Personnel Error.Stroke Testing Suspended & Surveillance Testing completed.W/930628 Ltr ML20045B4701993-06-11011 June 1993 LER 93-021-00:on 930611,determined That RB Ventilation Exhaust Inboard Isolation Valve HV-AOV-261AV Inoperable & Open Due to Personnel Error.Subj Valve Manually Closed. Proposed Change to TS Will Be submitted.W/930611 Ltr ML20045A5431993-06-0505 June 1993 LER 93-020-00:on 930507,determined That H2/O2 Sys Not Leak Tested to Verify Primary Containment Integrity During Testing of Sys.Caused by Failure to Have Administrative Controls in Place.Pressure Testing conducted.W/930605 Ltr ML20045A4331993-06-0101 June 1993 LER 93-SO1-00:on 930429,discoverd That Individual Had Tested Positive for Drugs at Another Facility on 930226.Employer Had Not Previously Been Notified.Approved Contractor Access Authorization Program suspended.W/930601 Ltr ML20045A4611993-06-0101 June 1993 LER 93-019-00:on 930501,nonconservative Testing Methodology Discovered During LLRT Due to Nonconservative Interpretation of Info Supplied by Valve Mfg.Testing Conducted for Valves Not Previously tested.W/930601 Ltr ML20044G8011993-05-28028 May 1993 LER 93-017-00:on 930428,discovered That Hourly Fire Watch Patrol for RB Per TS Had Not Been Performed.Caused by Personnel Error.Review of Fire Watch Patrol Implementation Process Will Be conducted.W/930528 Ltr ML20044E6301993-05-20020 May 1993 LER 93-015-00:on 930420,design Discrepancy in HPCI Sys Identified.Caused by Design Deficiency in Original Design. Mods Will Be Made to Startup from Current Refueling Outage to Correct Design discrepancy.W/930520 Ltr ML20044D8211993-05-17017 May 1993 LER 93-014-00:on 930316,small through-wall Leak Developed on High Pressure Side of SW Throttle Valve.Caused by Inadequate Valve Design.Frequency of Visual Insp of Valve Internals Will Be Increased to Once Per cycle.W/930517 Ltr ML20044D6511993-05-15015 May 1993 LER 93-013-00:on 930415,determined That as-found Setpoint for Seven SRVs Not within TS Limit.Caused by Lift Setpoint Discrepancies of Srvs.Review of Setpoint Data Will Be performed.W/930515 Ltr ML20044D5341993-05-14014 May 1993 LER 93-012-00:on 930414,violation of Primary Containment Integrity Occurred.Caused by Personnel Error.Procedure Change Being Made to Eliminate Test Return Line Venting When Primary Containment Integrity required.W/930514 Ltr ML20044D2041993-05-12012 May 1993 LER 93-011-00:on 930308,max Differential Pressure Between Reactor Bldg & External Environ of -0.22-inches Water Gauge Exceeded TS Required Min.Caused by Lack of Loop Seal on Rupture Seal Drain Line.Seals replaced.W/930512 Ltr ML20024G7421991-04-23023 April 1991 LER 91-002-00:on 910324,RWCU Occurred Due to High Sys Temp During Plant Cooldown.Caused by Failed Temp Indication & Potential Equipment Failure.Failed Thermocouple & Temp Switch Replaced & calibr.W/910423 Ltr ML20043D2311990-05-30030 May 1990 LER 90-005-00:on 900430,reactor Protection Sys B Motor Generator Set Output Breaker Tripped.Caused by Equipment Malfunction & Preventive Maint Program Deficiency.Sys Restored to Pretrip Operational state.W/900530 Ltr ML20042G9411990-05-10010 May 1990 LER 90-004-00:on 900413,ESF Group Isolations & Diesel Generator Starts Occurred Due to Equipment Malfunction & Personnel Error.Equipment Repaired,Manual Disconnect Operating Location Labeled & Personnel trained.W/900510 Ltr ML20011F1321990-02-23023 February 1990 LER 90-001-00:on 900124,outboard Steam Supply Line Isolation Valve Unexpectedly Closed During Surveillance Testing,Causing Isolation of HPCI Sys.Caused by Procedural Inadequacy.Test Procedure Will Be upgraded.W/900223 Ltr ML20005E3331989-12-26026 December 1989 LER 89-026-00:on 891125,reactor Scram Occurred Due to Closure of Outboard Msivs.Caused by post-filter Media Ignition by Hot Air or Particles from Dryer.Air Dryer B Disassembled & inspected.W/891226 Ltr ML19332F1191989-12-0707 December 1989 LER 88-016-02:on 880517,pipe Stress Analyses Revealed That Resultant Stresses for Five Piping Segments/Components Exceed Plant Design Basis.Caused by Support Design Problems. Long-term Corrective Program implemented.W/891207 Ltr ML19325E2201989-10-27027 October 1989 LER 89-025-00:on 890928,main Turbine Trip Occurred,Followed Immediately by Reactor Scram.Caused by Spurious Actuation of Level Switch Due to Equipment Vibration.Plant Stabilized & Temporary Instruction Re Pump Shifting issued.W/891027 Ltr ML20024C3571983-06-28028 June 1983 LER 83-008/03L-0:on 830530,HFA Relay 9-17-16A K6B Contacts Failed to Open.Cause Not Determined.Relay Coil Replaced. Systematic Replacement of All Relays within 4-yr Period planned.w/830628 Ltr ML20028F0921983-01-20020 January 1983 LER 82-025/03L-0:on 821222,coil of Reactor Protection Relay 915-5AK8C Overheated.Relay Did Not Fail.Cause Undetermined. Relay Replaced & Proper Operation Verified ML20028F0781983-01-20020 January 1983 LER 82-024/03L-0:on 821221,pressure Switch RHR-PS-120A Setpoint Found Outside Range Specified in Tech Specs.Caused by Failed Diaphragm.Pressure Switch Adjusted & Subsequent Testing Showed Nonrepeatable Trip Point.Switch Replaced ML20028B4671982-11-22022 November 1982 LER 82-022/03L-0:on 821025,RHR Time Delay Relay 10A-K45A Failed to Operate within Required Time Limits.Caused by Setpoint Being Set Too Conservatively.Relay Readjusted & Correct Operation Verified ML20028B4661982-11-19019 November 1982 LER 82-021/03L-0:on 821023,relay 917-16A-K44B Failed to Open Contacts When de-energized.Cause Not Determined.Relay Replaced & Correct Operation Verified.Monitoring Program Implemented to Determine Need for Generic Replacement ML20052G5321982-05-0606 May 1982 LER 82-008/03L-0:on 820415,during Diagnostic Testing of Mechanical Snubbers,Model PSA-10 SN/544 Snubber Exceeded Specified Acceleration Rate.Caused by Improper Installation of Clutch Spring.Snubber Sent to Manufactures for Repair ML20052B4041982-04-22022 April 1982 LER 82-007/03L-0:on 820324,differential Pressure Between Drywell & Suppression Chamber Reduced Below Tech Spec Limits During RHR Test Mode Operation.Caused by Nitrogen Flow from Drywell to Suppression Chamber.Return Piping to Be Modified ML20052A3561982-04-21021 April 1982 LER 82-006/03L-0:on 820322,while Inerting Drywell,Ductwork Between Primary Containment & Reactor Bldg Ventilation Found Failed in Several Places,Preventing Oxygen Concentration & Differential Pressure from Being Established ML20050B2101982-03-19019 March 1982 LER 82-005/03L-0:on 820221,MSIV-86A Found to Have Closing Time Faster than Tech Spec.Cause Unknown.Closing Time Adjusted & Control Valve Locked Into Required Position ML20041F8271982-03-0505 March 1982 LER 82-004/03L-0:on 820109,during Planned Power Reduction, Min Critical Power Ratio Was Below Operating Limit W/O Initiation of Corrective Actions Required by Tech Specs. Caused by Personnel Error.Procedures Will Be Revised ML20041C4151982-02-18018 February 1982 LER 81-003/03L-1:on 810223,valve RHR-MO-26B Motor Current Increased & Remained High When Valve Reached Closed Position.Valve Motor Breaker Manually Tripped & Valve Declared Inoperable.Caused by Failure of Brake Coil ML20041C3881982-02-17017 February 1982 LER 82-003/03L-0:on 820126,overload Alarm Condition Received While Closing Valve RHR-MO-26B,caused by Motor Brake Coil Failing to Release.New Motor & Brake Installed & Tested Satisfactorily ML20041C3741982-02-17017 February 1982 LER 82-002/03L-0:on 820121,during Routine Surveillance Testing NBI-LIS-101A Found to Trip at Lower than Tech Spec Limits.Caused by Barton Model 288 Switch Actuating at Random Positions.Switch Replaced ML20041C3871982-02-17017 February 1982 LER 82-001/03L-0:on 820122,reactor Vessel Level Switch NBI-LIS-72C Failed to Trip at Tech Spec Setpoint.Caused by Misalignment of Switch Mechanism.New Switch Calibr & Installed ML20040D3491982-01-20020 January 1982 LER 81-026/03L-0:on 811223,switches NBI-LIS-01A & NBI-LIS- 101B Found Set at Level Lower That Tech Spec Limits.Caused by Setpoint Drift.Switches Returned to Correct Setpoints. Instrument Drift to Be Closely Monitored ML20040D9261982-01-0505 January 1982 LER 81-025/04T-0:on 811224,during Full Power,Discharge Was Made from Floor Drain Sample Tank W/O Adequate Sampling & Analysis of Batch.Caused by Personnel Error.Liquid Discharge Procedures Being Revised.Personnel Reprimanded ML20038C5321981-12-0303 December 1981 LER 81-024/03L-0:on 811106,safety Relief Valve 71-D Failed to Close After Test.Caused by Failure of Solenoid Plunger to Drop Out When Solenoid de-energized.Solenoid Replaced ML20010G0961981-08-25025 August 1981 LER 81-020/03L-0: on 810728, During Procedure Returning Diesel Generator 1 to Svc After Flexible Fuel Line Leak, Control Air Line Fitting Failed Causing Generator to Shut Down. Caused by Broken Air Line Due to Crimped Ferrule ML20010F9881981-08-25025 August 1981 LER 81-019/03L-0:on 810728,during Surveillance to Prove Operability of Diesel Generator 1,fuel Supply Hose Developed Leak.Caused by Excessive Localized Flexure & Vibration. Hose Replaced ML20010G2661981-08-25025 August 1981 LER 81-021/03L-0:on 810728,during Performance of Surveillance Procedure on Diesel Generator 2,injection Line Failed.Caused by Metal Fatigue & Vibration.Component Replaced ML20010A1391981-07-22022 July 1981 LER 81-018/03L-0:on 810625,pressure Switch NBI-PS-52A Found W/Trip Point Less Conservative than Tech Spec.Apparently Caused by Setpoint Drift.Switch Readjusted.Setpoints for Switches Reset ML20010A1671981-07-13013 July 1981 LER 81-017/03L-0:on 810613,reactor Core Isolation Cooling Sys Steam Supply Valve RCIC-MOV-M016 Failed to Open.Caused by Improperly Wired Motor Operator Circuit.Jumper Installed ML20010A5391981-07-0909 July 1981 LER 81-016/03L-0:on 810610,core Thermal Power Calculation Performed by Process Computer Found Incorrect Due to Incorrect Feedwater Flow Value in Computer.Caused by Personnel Error in Changing Conversion Coefficient 1994-05-13
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20212K9781999-09-30030 September 1999 Safety Evaluation Accepting USI A-46 Implementation Program ML20217A9931999-09-30030 September 1999 NRC Regulatory Assessment & Oversight Pilot Program, Performance Indicator Data ML20217G7461999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for Cooper Nuclear Station ML20217A1691999-09-22022 September 1999 Part 21 Rept Re Engine Sys,Inc Controllers,Manufactured Between Dec 1997 & May 1999,that May Have Questionable Soldering Workmanship.Caused by Inadequate Personnel Training.Sent Rept to All Nuclear Customers ML20212C5001999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Cooper Nuclear Station ML20211D6491999-08-25025 August 1999 Part 21 Rept Re Nonconformance within LCR-25 safety-related Lead Acid Battery Cells Manufactured by C&D.Analysis of Cells Completed.Analysis of Positive Grid Matl Shows Nonconforming Levels of Calcium within Positive Grid Alloy ML20210R0381999-07-31031 July 1999 Monthly Operating Rept for July 1999 for Cooper Nuclear Station ML20210J2921999-07-29029 July 1999 Special Rept:On 990406,OG TS & Associated Charcoal Absorbers Were Removed from Svc.Caused by Scheduled Maint on Hpci. Evaluation of Offsite Effluent Release Dose Effects Was Performed to Ensure Plant Remained in Compliance ML20209H8281999-07-15015 July 1999 Safety Evaluation Accepting GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves, for Cooper Nuclear Station ML20211A9981999-07-12012 July 1999 Draft,Probabilistic Safety Assessment, Risk Info Matrix, Risk Ranking of Systems by Importance Measure ML20196H8621999-06-30030 June 1999 NRC Regulatory Assessment & Oversight Pilot Program, Performance Indicator Data, June 1999 Rept ML20209E1061999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Cns.With ML20196B3851999-06-17017 June 1999 Summary Rept of Facility Changes,Test & Experiments,Per 10CFR50.59 for Period 970901-990331.Summary of Commitment Changes Made During Same Time Period Also Encl ML20195K2851999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Cooper Nuclear Station.With ML20206P0481999-05-12012 May 1999 Safety Evaluation Concluding That NPP Established Acceptable Program to Verify Periodically design-basis Capability of safety-related MOVs at CNS & Adequately Addressed Actions Requested in GL 96-05 ML20206J0811999-05-0404 May 1999 Rev 14 to CNS QA Program for Operation ML20206P9751999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Cooper Nuclear Station ML20205Q0891999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Cooper Nuclear Station.With ML20204G8951999-03-15015 March 1999 CNS Inservice Insp Summary Rept Fall 1998 Refueling Outage (RFO-18) 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 ML20204B3701999-03-11011 March 1999 SER Accepting Third 10-year Interval Inservice Insp Plan Requests for Relief for RI-17,Rev 1 and RI-25,Rev 0.Request for Relief RI-13,Rev 2 Involving Snubber Testing & Is Being Evaluated in Separate Report ML20204C9751999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Cooper Nuclear Station ML20199E6751999-01-14014 January 1999 Monthly Operating Rept for Dec 1998 for Cooper Nuclear Station ML20195B9191998-12-31031 December 1998 1998 NPPD Annual Rept. with ML20196J9641998-12-0707 December 1998 Safety Evaluation Accepting Licensee Third 10-yr Interval Inservice Insp Plan Request for Relief RI-27,rev 1 ML20198D2471998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Cooper Nuclear Station.With ML20196A2861998-11-23023 November 1998 SER Re Core Spray Piping Weld for Cooper Nuclear Station. Staff Concluded That Operation During Cycle 19 Acceptable with Indication re-examined During RFO 18 ML20196A5241998-11-23023 November 1998 Safety Evaluation Accepting Proposed Alternative to Use UT Techniques Qualified to Objectives of App Viil as Implemented by PDI Program in Performing RPV Shell Weld & Shell to Flange Weld Examinations ML20196A5061998-11-23023 November 1998 Safety Evaluation Re Flaw Indication Found in Main Steam Nozzle to Shell Weld NVE-BD-N3A at Cns.Plant Can Be Safely Operated for at Least One Fuel Cycle with Indication in as-is Condition ML20196C4241998-11-20020 November 1998 Rev 1 to Cooper Nuclear Station COLR Cycle 19 ML20195H1761998-11-17017 November 1998 SER Authorizing Proposed Alternative in Relief Requests RV-06,RV-07,RV-09,RV-11,RV-12 & RV-15 Pursuant to 10CFR50.55a(a)(3)(ii).RV-08 Granted Pursuant to 10CFR50.55a(f)(6)(i) & RV-13 Acceptable Under OM-10 ML20195F8601998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Cooper Nuclear Station.With ML20155D9961998-10-31031 October 1998 Rev 0 to GE-NE-B13-01980-24, Fracture Mechanics Evaluation on Observed Indication at N3A Steam Outlet Nozzle to Shell Weld at Cooper Nuclear Station ML20154Q5661998-10-0505 October 1998 Rev 0 to CNS COLR Cycle 19 ML20154L5381998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Cooper Nuclear Station.With ML20151Z6141998-09-16016 September 1998 SER Accepting Util Responses to NRC Bulletin 95-002 for Cooper Nuclear Station ML20154F7931998-08-31031 August 1998 Rev 0 to J11-03354-10, Supplemental Reload Licensing Rept for CNS Reload 18,Cycle 19 ML20153B1101998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for Cooper Nuclear Station ML20237E7771998-08-20020 August 1998 Revised COLR Cycle 18 for Cooper Nuclear Station ML20151Q1211998-08-14014 August 1998 Rev 0 to Control of Hazard Barriers ML20237C0591998-07-31031 July 1998 Monthly Operating Rept for Jul 1998 for Cooper Nuclear Station ML20236R9131998-07-20020 July 1998 SER Accepting Rev 13 to Quality Assurance Program for Operation Policy Document for Plant ML20236P2971998-07-0707 July 1998 Rev 2 to NPPD CNS Strategy for Achieving Engineering Excellence ML20236R0931998-06-30030 June 1998 Monthly Operating Rept for June 1998 for Cooper Nuclear Station ML20249A7701998-05-31031 May 1998 Monthly Operating Rept for May 1998 for Cooper Nuclear Station ML20247G6131998-05-13013 May 1998 Part 21 Rept Re Defect Contained in Automatic Switch Co, Solenoid Valves,Purchased Under Purchase Order (Po) 970161. Caused by Presence of Brass Strands.Replaced Defective Valves ML20247G0951998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for Cooper Nuclear Station ML20237B6861998-04-24024 April 1998 Vols I & II to CNS 1998 Biennial Emergency Exercise Scenario, Scheduled for 980609 ML20217A1531998-04-16016 April 1998 Closure to Interim Part 21 Rept Submitted to NRC on 970929. New Date Established for Completion of Level I & 2 Setpoint Project Committed to in .Final Approval of Setpoint Calculations Will Be Completed by 980531 ML20216G5331998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for Cooper Nuclear Station 1999-09-30
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Text
- COOPER NUCLEAR ET ATION Nebraska Public Power District "" "
.e CNSS933054 March 18, 1993 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555
Dear Sir:
Cooper Nuclear Station Licensee Event Report 93-001, Revision 0, is forwarded as an attachment to this letter.
Sincerely,
. L. Gardner Plant Manager RLG/ju Attachment ec: J. L. Milhoan ;
G. R. Horn J. M. Meacham i
R. E. Wilbur V. L. Wolstenholm l D. A. Whitman l
INPO Records Center NRC Resident Inspector R. J. Singer CNS Training ,
CNS Quality Assurance j i
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- THE PAPE Rwopet Rf DUCTION PROJECT (31b00104), OFFICE i OF MANAGEME NT AND BUDGET, WASHINGTON.DC 20bO3. .;
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F ACILITV NAME (11 jDCCkET NUMBER (2)
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t Potential for Incufficient Component Cooling During A Design Basis Accident Duc To l Desien Discremancles With The Service Water And Reactor Equipment Cooling Systems ;
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. NO l l' l Am R ACT u ,. ,m ., c . . . % ,s -,-. ,-, ua , nei i During ongoing efforts associated with the Design Basis Reconstitution Program for !
) Cooper Nuclear Station (CNS), several design discrepancies in the Service Water (SW) '
and Reactor Equipment Cooling (REC) Systems were identified. These discrepancies l affected the ability to achieve the minimum required SW and REC flows to essential equipment requiring cooling during and following a design basis accident (DBA). On ,
February 25, at 12:30 pm, both systems were declared inoperable and the 2411our LCO requiring plant shutdown specified in Technical Specifications was entered. At the time of entry into the LCO, the plant was operating at approximately 85 percent {
power (nearly 700 MWe) on end of cycle coastdown with all rods fully withdrawn.
d 1 Review of design and construction documentation revealed that a SW piping (
configuration error was made during original plant construction, resulting in
- Division 1 SW being supplied to the Division II REC Heat Exchanger, and vice-versa. [
' While subsequent evaluations were performed by the Architect / Engineer resulting in system operational ch'nges to compensate for the as-built condition, apparently the i analyses were not sufficiently thorough to identify and resolve these concerns.
Compensatory measures taken to restore the SW and REC Systems to an operable status !
included interim procedure changes providing operator guidance and system valve '
alignment restrictions. Additionally, operators were briefed regarding the scenarios of concern and the necessary compensatory actions requircd. These actions were in effect until the plant achieved cold shutdown for the 1993 Refueling Outage which began on March 5. Prior to startup from the outage, pertinent mechanical and '
electrical modifications will be made to resolve the identified concerns.
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A. Event Description I 1
During ongoing efforts associated with the Nebraska Public Power ';
District's Design Basis Reconstitution Program for Cooper Nuclear !
Station (CNS), several design discrepancies in_the Service Water _(SW)- !
and Reactor Equipment Cooling (REC) Systems were identified. These i discrepancies involved the ability to a.:hieve the minimum required'SW ; j and REC flows to the essential equipment requiring cooling during and ;
following a design basis accident (DBA). On February 25, at 12:15 pm, !'
an evaluation of the discrepancies was conducted by the Station Operations Review Committee (SORC). A recommendation was then inade to i the Shift Supervisor to declare the SW and REC Systems inoperable and l enter the 2411our LCO requiring plant shutdown specified in s4ctions i 3.12.B.4 (REC System) and 3.12.C 3 (SW System) of the Technica.1 ;!
Specifications. Both systems were subsequently declared inoperable at !
12:30 pm and the 24 Ilour LCO was entered. !
DBA conditions include a loss-of-coolant accident (LOCA) with a concurrent loss-of-offsite power (IAOP) and a worst case single failure.
The postulated worst case single failure is a failure of one emergency diesel generator (DC), since this causes the failure of the most SW and REC components. Under these conditions, if both REC IIeat Exchangers are -
in service prior to the accident, _It may not be possibic to remotely isolate the heat exchanger in the loop that serves the Core Standby.
Cooling Systems (CSCS) equipment in the failed electrical division. For example, if DG No. I fails and all off-site power is lost, valve REC-MOV-711MV (the South Critical Loop Supply Valve) will not;open since it is powered by Division 1. Thus, only REC lleat Exchanger B is available for critical loop component cooling. With both heat exchangers in service at the start of the event and both SW outlet' valves open, it would not be possible without manual operator action to isolate the SW flow to llent Exchanger A since the REC A Heat Exchanger SW System outlet valve (SU-MOV-651MV) is a Division I valve.
Consequently, a flow diversion proportional to the flow established !
prior to the accident would be directed to the "A" REC Heat Exchanger ,
l which would be non-functional; i.e., providing no useful accident I response purpose. With this flow diversion, it may not be possible to-provide the minimum required flow to the operable DG, the functional !
REC liest Exchanger, the Residual lleat Removal (RHR) SW Booster Pump and j other. cooling loads. l The REC System is also not single failure proof in the accomplishment of l its safety function. The automatic isolation valves that isolate the i noncritical header of REC from the critical header are all powered from ~
i Division I electrical power. In the case of a Design Basis LOCA, IDOP and failure of DG No. 1 (DG No. 1 only), the noncritical header does not automatien11y isolate. _As a result, REC flow would be diverted to the nonessential evoling loads.
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0 10 0l3 OF 0 l4 i A. Event Descrintion - (continued)
With only one REC pump in operation, the essential CSCS area coolers and the RHR Pump seal coolers might not receive the required cooling flow.
In the event of a LOCA, LOOP and loss of DG No. 2, REC flow will be diverted to the noncritical header since REC-MOV-702MV, the Noncritical Header Drywell Supply Isolation Valve, does not receive the low header pressure isolation signal that is received by the other two noncritical ,
loop isolation valves. Thus, remote manual action from the Control Room i must be taken to isolate the valves on the suction side of the REC Pumps to prevent diversion of the REC flow through the noncritical header. ;
i B. flant Status Operating at approximately 85 percent power, at nearly 700 MWe, on ,
end of cycle coastdown with all rods fully withdrawn.
4 C. Basis for Report 1
A condition alone that could have prevented the fulfillment of the j safety function of systems needed to mitigate the consequences of an accident, reportable in accordance with 10CFR50.73(a)(2)(v). :
D. Cnuse A review of documentation associated with the design and construction of ;
the associated systems revealed that a SW piping configuration error (
during original plant construction occurred, resulting in Division I SW being supplied to the Division II REC Heat Exchanger, and vice-versa.
While subsequent failure modes and effects analyses performed by the ,
Architect / Engineer resulted in system operational changes to compensate for the as-built condition, apparently the analyses were not ;
sufficiently thorough to identify and resolve these concerns. t E. Safetv Sinnificance ,
The safety objective of the SW System is to provide a heat sink for the REC, RHR, and DG cooling systems under transient and accident ;
conditions. However, adequate SW flow to all of the required cooling l loads was not assured under postulated LOCA, LOOP and concurrent worst '
case single f allure conditions, without operator action from the Control ,
Room. Existing operating procedures direct the operator to start a !
second SW pump in the event that the SW header pressure.is low, as it !
could be under the postulated accident scenario. Calculations show'that adequate power is available from a DG to support operation of this second pump. Also, calculations show that the operator has at least ten ;
minutes to accomplish this remote manual action from the' Control Room.- I which is within the.CNS licensing basis- and is a reasonable. response !
time. Consequently, the safety objective of the SW System would have been achieved.
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E. Safety Sirnificance - (continued)
The safety objective of the REC System is to provide cooling to the CSCS area coolers and the RER pumps seal coolers, liowever, in the event of a LOCA, LOOP and worst caso single failure condition, the noncritical header will not be automatically isolated from the critical header as a result of low header pressure, an expected condition with only one pump in service. Adequate system flow to the CSCS area coolers and the RllR pumps seal coolers still might not be sufficient even if a second REC pump were started. Therefore, the safety objective of the REC System was jeopardized. {
i F. Safety Imnlications I l
The event which must occur in order for the SW and REC Systems to be of concern is a Design Basis LOCA, which assumes a concurrent LOOP and a ;
simultaneous failure of one DC. The probability of these-three i unrelated events occurring simultaneously is extremely remote (on the .. i order of 10-8 per year of reactor operation).
C. Corrective Actiqn Compensatory measures taken to restore the SW and-REC Systems to an operable status included interim procedure changes which provided ;
operator guidance and valve alignment restrictions associated with the ;
SW and REC Systems, along with operator briefings regarding the scenarios of concern and necessary compensatory actions that would be ;
required upon their occurrence. At approximately 10:00 pm on February 25, SORC reviewed and approved the basis for continued aparation uithin the hour, the required compensatory measures were in place and both the SW and REC Systems were declared operable. Thesc 1 compensatory actions were in effect until the plant achieved cold !
shutdown for the 1993 Refueling Outage which commenced on March 5.
Prior to startup from the refueling outage, necessary mechanical and ;
electrical modifications will be made to resolve the identified ;
concerns. !
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