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Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER)
MONTHYEARU-603232, Special Rept:On 990531 Lpms Was Declared Inoperable Due to Receipt of High Vibration & Loose Parts Alarm Which Did Not Clear.Lpms Was Restored to Operable Status on 990707 After Alignment & Tension on Recorder Tape Drive Was Adjusted1999-07-0909 July 1999 Special Rept:On 990531 Lpms Was Declared Inoperable Due to Receipt of High Vibration & Loose Parts Alarm Which Did Not Clear.Lpms Was Restored to Operable Status on 990707 After Alignment & Tension on Recorder Tape Drive Was Adjusted U-603101, Special Rept:On 980918,discovered That Triaxial Seismic Accelerometers Had Not Been Properly Calibrated.Caused by Inadequate Calibration Procedure.Calibration to Be Performed off-site1998-10-28028 October 1998 Special Rept:On 980918,discovered That Triaxial Seismic Accelerometers Had Not Been Properly Calibrated.Caused by Inadequate Calibration Procedure.Calibration to Be Performed off-site U-603014, Special Rept:On 980512,lightning Struck Primary Meteorological Monitoring Instrumentation Tower Damaging 60- Meter Wind Speed & Associated Transmuter Circuit Card. Surveillance Testing Performed1998-05-28028 May 1998 Special Rept:On 980512,lightning Struck Primary Meteorological Monitoring Instrumentation Tower Damaging 60- Meter Wind Speed & Associated Transmuter Circuit Card. Surveillance Testing Performed U-602940, Ro:On 980213,alert Emergency Classification Was Declared IAW EPIP EC-02, Emergency Classifications. Caused by Tripped Inverter.Rhr a Was Restored at Approx 0945 H & Emergency Terminated at 1004 H Per EPIP EC-04, Alert1998-02-20020 February 1998 Ro:On 980213,alert Emergency Classification Was Declared IAW EPIP EC-02, Emergency Classifications. Caused by Tripped Inverter.Rhr a Was Restored at Approx 0945 H & Emergency Terminated at 1004 H Per EPIP EC-04, Alert U-602921, Special Rept:On 980113,operations Personnel Declared Meteorological Tower Wind Direction Instrumentation Inoperable.Consistent Difference Suspected to Have Been Caused by Rotation of Either or Both of Wind Sensor1998-01-29029 January 1998 Special Rept:On 980113,operations Personnel Declared Meteorological Tower Wind Direction Instrumentation Inoperable.Consistent Difference Suspected to Have Been Caused by Rotation of Either or Both of Wind Sensor U-602599, Special Rept:On 960516,Loose Parts Monitoring System Declared Inoperable.Caused by Intermittent Alarms.Removed Temporary Mod & Restored Alarm Feature for Channel Three1996-06-21021 June 1996 Special Rept:On 960516,Loose Parts Monitoring System Declared Inoperable.Caused by Intermittent Alarms.Removed Temporary Mod & Restored Alarm Feature for Channel Three U-602534, Special Rept:On 951206,determined Facility May Have Been Operated Above Max Power Level Authorized by License Due to Error in Reactor Heat Balance.Util Will Bias CRD Sys Flow Process Computer Point1996-01-0303 January 1996 Special Rept:On 951206,determined Facility May Have Been Operated Above Max Power Level Authorized by License Due to Error in Reactor Heat Balance.Util Will Bias CRD Sys Flow Process Computer Point U-602527, Special Rept:On 951103,reactor Water Cleanup Sys Flow Rate Computer Valve Substituted W/Value of Zero & Sys Actually Operating.Caused by Lack of Attention.Shift Technical Advisor Immediately Restored Computer1995-12-0505 December 1995 Special Rept:On 951103,reactor Water Cleanup Sys Flow Rate Computer Valve Substituted W/Value of Zero & Sys Actually Operating.Caused by Lack of Attention.Shift Technical Advisor Immediately Restored Computer U-602426, Ro:On 950301,plant Was Operating at Approx 75% Fire Was Reported in a turbine-driven Reactor Feed Pump Room1995-03-0303 March 1995 Ro:On 950301,plant Was Operating at Approx 75% Fire Was Reported in a turbine-driven Reactor Feed Pump Room U-602421, Ro:On 950216,Div 2 125 Volt Dc Electrical Power Sys Declared Inoperable.Caused by Failure of Silicon Controlled Rectifier Firing Board in Div 2 Battery Charger.Battery Charger Repaired1995-02-22022 February 1995 Ro:On 950216,Div 2 125 Volt Dc Electrical Power Sys Declared Inoperable.Caused by Failure of Silicon Controlled Rectifier Firing Board in Div 2 Battery Charger.Battery Charger Repaired U-602348, Special Rept:On 940906,CPS Declared Loose Parts Monitoring Sys Out of Svc.Caused by False Alarms.Util Will Recalibrate Channel Six1994-10-10010 October 1994 Special Rept:On 940906,CPS Declared Loose Parts Monitoring Sys Out of Svc.Caused by False Alarms.Util Will Recalibrate Channel Six U-602311, Special Rept:On 940624,inoperabilities of Meteorological Monitoring Instrumentation Channels for More than 7 Days Identified.Personnel Worked Expeditiously to Return Meteorological Instrumentation to Operable Status1994-07-12012 July 1994 Special Rept:On 940624,inoperabilities of Meteorological Monitoring Instrumentation Channels for More than 7 Days Identified.Personnel Worked Expeditiously to Return Meteorological Instrumentation to Operable Status U-602308, Special Rept:On 940607,determined Valid Failure of Div 1 EDG Had Occurred Due to Excessive Current.Replaced Failed Relay1994-07-0707 July 1994 Special Rept:On 940607,determined Valid Failure of Div 1 EDG Had Occurred Due to Excessive Current.Replaced Failed Relay U-602193, Special Rept:On 930927,valid Failure of Div II DG Occurred During Surveillance Testing.Caused by Insufficient Contact Pressure Between Contacting Surfaces.Contact Pressure Checks to Improve Component Reliability Implemented1993-10-12012 October 1993 Special Rept:On 930927,valid Failure of Div II DG Occurred During Surveillance Testing.Caused by Insufficient Contact Pressure Between Contacting Surfaces.Contact Pressure Checks to Improve Component Reliability Implemented U-602189, Follow-up Special Rept on Progress of Investigation Into Diesel I DG Test Failures That Occurred on 930623,0721 & 0803.Current Number of Valid Failures in Last 100 Valid Tests of DG1A Is Seven.Testing for DG1A Conducted1993-09-24024 September 1993 Follow-up Special Rept on Progress of Investigation Into Diesel I DG Test Failures That Occurred on 930623,0721 & 0803.Current Number of Valid Failures in Last 100 Valid Tests of DG1A Is Seven.Testing for DG1A Conducted U-602181, Special Rept:On 930812-30,differential Air Temp Instrumentation Inoperable.Caused by Problem W/Power Supply Panel 0EM01J.Replacement Power Supply Unavailable. Engineering Change Request ECN 28103 Processed1993-08-30030 August 1993 Special Rept:On 930812-30,differential Air Temp Instrumentation Inoperable.Caused by Problem W/Power Supply Panel 0EM01J.Replacement Power Supply Unavailable. Engineering Change Request ECN 28103 Processed U-602174, Special Rept:On 930721 & 0803,valid Test Failures of Div I DG Occurred Due to Problem W/Contacts within Breaker Control Switch & Failed Coil in B-C Phase Undervoltage Relay, Respectively.Subj Parts Will Be Replaced During DG Outage1993-08-20020 August 1993 Special Rept:On 930721 & 0803,valid Test Failures of Div I DG Occurred Due to Problem W/Contacts within Breaker Control Switch & Failed Coil in B-C Phase Undervoltage Relay, Respectively.Subj Parts Will Be Replaced During DG Outage U-602163, Special Rept:On 930623,Div I DG (DG1A) Failed to Synchronize W/Associated Safety Bus & Generator Output Breaker Tripped on Reverse Power Signal Due to Faulty Reverse Power Relay. DG1A Reverse Power Relay Replaced W/Newer Model1993-07-23023 July 1993 Special Rept:On 930623,Div I DG (DG1A) Failed to Synchronize W/Associated Safety Bus & Generator Output Breaker Tripped on Reverse Power Signal Due to Faulty Reverse Power Relay. DG1A Reverse Power Relay Replaced W/Newer Model U-602068, Ro:On 921107,ORIX-PR008 Was Declared Inoperable Due to Lo Fail Signal Received for Channel 3 Which Was Unable to Be Reset.Preplanned Alternate Method of Monitoring HVAC Stack Initiated1992-11-24024 November 1992 Ro:On 921107,ORIX-PR008 Was Declared Inoperable Due to Lo Fail Signal Received for Channel 3 Which Was Unable to Be Reset.Preplanned Alternate Method of Monitoring HVAC Stack Initiated U-602057, Special Rept:On 920921,generator Output Breaker Failed to Close on Four Attempts.Caused by Bent Protective Cover Over Auxiliary Switches & anti-pump Coil.Output Breaker Racked to Test Position & Sucessfully Cycled Three Times1992-10-20020 October 1992 Special Rept:On 920921,generator Output Breaker Failed to Close on Four Attempts.Caused by Bent Protective Cover Over Auxiliary Switches & anti-pump Coil.Output Breaker Racked to Test Position & Sucessfully Cycled Three Times U-602049, Ro:On 920922,Control Room Received Notification That Employee Working in Radwaste Sort Tent Had Been Injured & Potentially Contaminated.Ambulance Called to Respond.Hosp Notified Util That Victim Was Not Contaminated1992-09-28028 September 1992 Ro:On 920922,Control Room Received Notification That Employee Working in Radwaste Sort Tent Had Been Injured & Potentially Contaminated.Ambulance Called to Respond.Hosp Notified Util That Victim Was Not Contaminated U-602035, Special Rept:On 920717 & 0807,output Breaker Failed to Close During Periodic Testing of Dg.Caused by Failure of H1 trunk-operated Contact Switch Due to Slight Breaker Movement.Vendor Manual for Switchgear Will Be Reviewed1992-08-19019 August 1992 Special Rept:On 920717 & 0807,output Breaker Failed to Close During Periodic Testing of Dg.Caused by Failure of H1 trunk-operated Contact Switch Due to Slight Breaker Movement.Vendor Manual for Switchgear Will Be Reviewed ML20216J2861992-08-0808 August 1992 Special Rept:On 920712,determined That Valid Failure of Div 1 EDG Occurred.Caused by B-C Phase CV-2 Relay Telephone Coil Failing Due to Excessive Current.Design Change Mod Initiated.Also Reportable Per Part 21 U-601991, Ro:On 920522,discovered That External Vessel Surface Was Hot & Chart Recorder Indicated Absorber Bed Temp Greater than 300F.Fire Brigade Was Activated.Sampling Process Established to Monitor Purge Exhaust Composition1992-06-0101 June 1992 Ro:On 920522,discovered That External Vessel Surface Was Hot & Chart Recorder Indicated Absorber Bed Temp Greater than 300F.Fire Brigade Was Activated.Sampling Process Established to Monitor Purge Exhaust Composition U-601970, Special Rept:On 920328,diesel Generator 1B Manually Started But Stabilized Outside TS Range of 60 + or - Hz. Caused by Failure of Power Supply for Electronic Speed Controller.Power Supply Replaced1992-04-24024 April 1992 Special Rept:On 920328,diesel Generator 1B Manually Started But Stabilized Outside TS Range of 60 + or - Hz. Caused by Failure of Power Supply for Electronic Speed Controller.Power Supply Replaced U-601946, Special Rept:On 920302,meteorological Tower Differential Air Temp Instrumentation Declared Inoperable to Facilitate Troubleshooting Re Discrepancy in Meteorological Data. Missing Ducting Tube from Aspirator Installed1992-03-0606 March 1992 Special Rept:On 920302,meteorological Tower Differential Air Temp Instrumentation Declared Inoperable to Facilitate Troubleshooting Re Discrepancy in Meteorological Data. Missing Ducting Tube from Aspirator Installed U-601942, Revised Special Rept Re non-valid Test Failure of Div I DG, Describing Correct Steps Involved in Synchronizing DG W/ Offsite Power.Dg Output Voltage Adjusted Such That It Is Slightly Higher than Offsite Power Voltage1992-03-0202 March 1992 Revised Special Rept Re non-valid Test Failure of Div I DG, Describing Correct Steps Involved in Synchronizing DG W/ Offsite Power.Dg Output Voltage Adjusted Such That It Is Slightly Higher than Offsite Power Voltage U-601931, Special Rept:On 920109,diesel Generator 1A Tripped Due to Reverse Power.Caused by Improper Manual Loading Following Synchronization W/Offsite Power.Dg 1A Manually Started to Demonstrate Operability Per Surveillance Procedure 9080.011992-02-0505 February 1992 Special Rept:On 920109,diesel Generator 1A Tripped Due to Reverse Power.Caused by Improper Manual Loading Following Synchronization W/Offsite Power.Dg 1A Manually Started to Demonstrate Operability Per Surveillance Procedure 9080.01 U-601893, Special Rept:On 911001,ORIX-PRO12 Declared Inoperable in Order to Perform Channel Calibr in Accordance W/Ts Surveillance Requirement 4.3.7.5.Calibr Initially Performed by day-shift C&I Crew,Then Backshift Crew1991-10-17017 October 1991 Special Rept:On 911001,ORIX-PRO12 Declared Inoperable in Order to Perform Channel Calibr in Accordance W/Ts Surveillance Requirement 4.3.7.5.Calibr Initially Performed by day-shift C&I Crew,Then Backshift Crew U-601834, Special Rept:On 910404,during Surveillance Diesel Generator 1A Reached Required Voltage & Frequency But Failed to Close & Phase Undervoltage Relay B-C Tripped.Cause Not Determined.Racking Mechanism Will Be Inspected & Lubricated1991-05-0606 May 1991 Special Rept:On 910404,during Surveillance Diesel Generator 1A Reached Required Voltage & Frequency But Failed to Close & Phase Undervoltage Relay B-C Tripped.Cause Not Determined.Racking Mechanism Will Be Inspected & Lubricated U-601788, Special Rept:On 910106,Div II Diesel Generator Failed During Test.Caused by Malfunction of A-3 Relay Tachometer. Preventive Maint Task Will Be Issued to Remove,Inspect & Bench Test A-3 Relay Every Two Yrs1991-02-0505 February 1991 Special Rept:On 910106,Div II Diesel Generator Failed During Test.Caused by Malfunction of A-3 Relay Tachometer. Preventive Maint Task Will Be Issued to Remove,Inspect & Bench Test A-3 Relay Every Two Yrs U-601309, Ro:On 881111,generator Trip W/Reactor Scram Occurred Due to Sudden Pressure Actuation on 1C Main Power Transformer & Fire on Insulator of 1C Main Power Transformer Discovered. Fire Extinguished1988-11-12012 November 1988 Ro:On 881111,generator Trip W/Reactor Scram Occurred Due to Sudden Pressure Actuation on 1C Main Power Transformer & Fire on Insulator of 1C Main Power Transformer Discovered. Fire Extinguished U-601298, Ro:On 881026,Tech Spec 3.0.3 Entered Due to Declaring Control Room Ventilation Train a Inoperable.Caused by Faulty Flow Transmitter.Reactor Power Was Reduced & Calibr on Train a Flow Transmitter Performed1988-10-27027 October 1988 Ro:On 881026,Tech Spec 3.0.3 Entered Due to Declaring Control Room Ventilation Train a Inoperable.Caused by Faulty Flow Transmitter.Reactor Power Was Reduced & Calibr on Train a Flow Transmitter Performed U-601265, Ro:On 880901,HPCS Initiated & Injected Water Into Reactor for 28 During Maint Surveillance Activities on Reactor Water Level Transmitter.Injection Valve & HPCS Pump Secured. Notification of Unusual Event Lasted Approx 10 Minutes1988-09-0202 September 1988 Ro:On 880901,HPCS Initiated & Injected Water Into Reactor for 28 During Maint Surveillance Activities on Reactor Water Level Transmitter.Injection Valve & HPCS Pump Secured. Notification of Unusual Event Lasted Approx 10 Minutes U-601258, Special Rept:On 880803,accident Monitoring Instrumentation for HVAC Stack Declared Inoperable for More That 72 H.Caused by Underway Work to Perform Routine Channel Calibr.Plant Condition Rept Initiated1988-08-22022 August 1988 Special Rept:On 880803,accident Monitoring Instrumentation for HVAC Stack Declared Inoperable for More That 72 H.Caused by Underway Work to Perform Routine Channel Calibr.Plant Condition Rept Initiated U-601219, Ro:On 880623,maint Technician Badly Burned in 762-ft Radwaste Evaporator Vapor Body Room.Caused by Performing Work on Wrong Evaporator.Evaporator Secured & Technician Given Medical Attention1988-06-24024 June 1988 Ro:On 880623,maint Technician Badly Burned in 762-ft Radwaste Evaporator Vapor Body Room.Caused by Performing Work on Wrong Evaporator.Evaporator Secured & Technician Given Medical Attention U-601173, Special Rept:On 880329,discovered Failure of Wind Velocity & Direction Sensors on Facility Meteorological Tower.Caused by Inadvertent Exposure of Sensors to Weather.Sensor Assembly, Including Retaining Device Replaced1988-04-15015 April 1988 Special Rept:On 880329,discovered Failure of Wind Velocity & Direction Sensors on Facility Meteorological Tower.Caused by Inadvertent Exposure of Sensors to Weather.Sensor Assembly, Including Retaining Device Replaced U-601026, Summary Rept:On 870828,notification of Unusual Event Declared Per Emergency Plan Implementing Procedures EC-02. Personnel Informed of Bomb Threat Made Against Util.Security Levels Tightened & Searches Performed.No Explosives Found1987-08-31031 August 1987 Summary Rept:On 870828,notification of Unusual Event Declared Per Emergency Plan Implementing Procedures EC-02. Personnel Informed of Bomb Threat Made Against Util.Security Levels Tightened & Searches Performed.No Explosives Found U-601015, Ro:On 870816,protected Area Intrusion Detection Sys Deactivated Due to Severe Weather.Compensatory Measures in Place.Security Personnel Removed from Post booths.Closed- Circuit Television Observers Posted Until Weather Cleared1987-08-21021 August 1987 Ro:On 870816,protected Area Intrusion Detection Sys Deactivated Due to Severe Weather.Compensatory Measures in Place.Security Personnel Removed from Post booths.Closed- Circuit Television Observers Posted Until Weather Cleared U-601017, Ro:On 870819,bomb Threat Received.Security Levels Tightened. State of Il,Nrc Incident Response Ctr & NRC Resident Inspector Notified.No Explosives Located1987-08-20020 August 1987 Ro:On 870819,bomb Threat Received.Security Levels Tightened. State of Il,Nrc Incident Response Ctr & NRC Resident Inspector Notified.No Explosives Located U-601004, Ro:On 870804,notification of Unusual Event Declared Due to Inoperability of Channel 1B21-N697A,LPCS,LPCI & RHR B. Functional Test of Channel Performed & Device,Lpcs & LPCI Declared Operable.Notification of Unusual Event Terminated1987-08-0505 August 1987 Ro:On 870804,notification of Unusual Event Declared Due to Inoperability of Channel 1B21-N697A,LPCS,LPCI & RHR B. Functional Test of Channel Performed & Device,Lpcs & LPCI Declared Operable.Notification of Unusual Event Terminated ML20236B5881987-07-17017 July 1987 Special Rept:On 870610,loose Parts Monitoring Sys Channels Went Into Alarm & Could Not Be Reset.Caused by Flow Noise from Reactor Recirculation Sys Flow Control Valve in Throttled Position.Alarm Temporarily Disabled U-600977, Ro:On 870704,protected Area Intrusion Detection Sys Deactivated Due to Severe Weather.Compensatory Measures Not Taken Due to Personnel Safety.Util Will Review Area of Formal Communications & Take Corrective Actions1987-07-11011 July 1987 Ro:On 870704,protected Area Intrusion Detection Sys Deactivated Due to Severe Weather.Compensatory Measures Not Taken Due to Personnel Safety.Util Will Review Area of Formal Communications & Take Corrective Actions U-600970, Special Rept:On 870608,plant Failed to Reach Rated Voltage & Rated Speed in Equal to or Less than 12 S.Caused by Linkage Connecting Shaft to Fuel Rack Out of Alignment.Alignment Requirements & Linkage Reworked1987-07-0808 July 1987 Special Rept:On 870608,plant Failed to Reach Rated Voltage & Rated Speed in Equal to or Less than 12 S.Caused by Linkage Connecting Shaft to Fuel Rack Out of Alignment.Alignment Requirements & Linkage Reworked U-600964, Special Rept:On 870610,earthquake Estimated to Be 5.0 on Richter Scale Noted.Walkdowns of Plant Structures & Sys Conducted.No Damage or Abnormal Conditions Observed.Related Info,Including Sargent & Lundy ...Seismic...Rept, Encl1987-06-19019 June 1987 Special Rept:On 870610,earthquake Estimated to Be 5.0 on Richter Scale Noted.Walkdowns of Plant Structures & Sys Conducted.No Damage or Abnormal Conditions Observed.Related Info,Including Sargent & Lundy ...Seismic...Rept, Encl U-600956, Final Status of Repair & Anticipated Schedule for Restoration of Remaining Out of Svc Annunciators.One Annunciator Listed in Groups 1 & 2 of Util Remain to Be Repaired1987-06-11011 June 1987 Final Status of Repair & Anticipated Schedule for Restoration of Remaining Out of Svc Annunciators.One Annunciator Listed in Groups 1 & 2 of Util Remain to Be Repaired U-600947, Notification of Unusual Event:On 870524,motor-driven Feed Pump Regulating Valve 1FW-F004 Malfunctioned,Increasing Reactor Water Level.Cause Under Investigation.Valve Shifted to Manual Control W/No Response.Event Terminated Same Day1987-05-26026 May 1987 Notification of Unusual Event:On 870524,motor-driven Feed Pump Regulating Valve 1FW-F004 Malfunctioned,Increasing Reactor Water Level.Cause Under Investigation.Valve Shifted to Manual Control W/No Response.Event Terminated Same Day U-600941, Special Rept:On 870411,operator Discovered No Power to Play Back Pens (All Lights Out) of Playback Unit.Caused by Blown Fuses of Recorder,Playback & Analyzer.Sensor & Portion of Circuit Boards Have Been Replaced1987-05-21021 May 1987 Special Rept:On 870411,operator Discovered No Power to Play Back Pens (All Lights Out) of Playback Unit.Caused by Blown Fuses of Recorder,Playback & Analyzer.Sensor & Portion of Circuit Boards Have Been Replaced U-600928, Ro:On 870506,reactor Manually Scrammed When Reactor Pressure Vessel Level Began to Rise.Caused by Failure of Feedwater Valve Controlling Flow of Water to Reactor to Open.Reactor Shut Down.State of Il & NRC Response Ctr Notified1987-05-0606 May 1987 Ro:On 870506,reactor Manually Scrammed When Reactor Pressure Vessel Level Began to Rise.Caused by Failure of Feedwater Valve Controlling Flow of Water to Reactor to Open.Reactor Shut Down.State of Il & NRC Response Ctr Notified U-600890, Ro:On 870322,containment Isolation Occurred on Instrument Air Sys During Surveillance of ECCS Reactor Water Level Channel Functional Checklist.Cause Not Stated.Reactor Shut Down1987-03-23023 March 1987 Ro:On 870322,containment Isolation Occurred on Instrument Air Sys During Surveillance of ECCS Reactor Water Level Channel Functional Checklist.Cause Not Stated.Reactor Shut Down 1999-07-09
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARU-603277, Monthly Operating Rept for Sept 1999 for Clinton Power Station,Unit 1.With1999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for Clinton Power Station,Unit 1.With 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 U-603267, Monthly Operating Rept for Aug 1999 for Clinton Power Station,Unit 1.With1999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Clinton Power Station,Unit 1.With U-603245, Monthly Operating Rept for Jul 1999 for CPS Unit 1.With1999-07-31031 July 1999 Monthly Operating Rept for Jul 1999 for CPS Unit 1.With ML20211C9621999-07-26026 July 1999 ISI Summary Rept U-603232, Special Rept:On 990531 Lpms Was Declared Inoperable Due to Receipt of High Vibration & Loose Parts Alarm Which Did Not Clear.Lpms Was Restored to Operable Status on 990707 After Alignment & Tension on Recorder Tape Drive Was Adjusted1999-07-0909 July 1999 Special Rept:On 990531 Lpms Was Declared Inoperable Due to Receipt of High Vibration & Loose Parts Alarm Which Did Not Clear.Lpms Was Restored to Operable Status on 990707 After Alignment & Tension on Recorder Tape Drive Was Adjusted U-603233, Monthly Operating Rept for June 1999 for Clinton Power Station,Unit 1.With1999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Clinton Power Station,Unit 1.With U-603222, Monthly Operating Rept for May 1999 for Clinton Power Station.With1999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Clinton Power Station.With ML20210K8391999-05-11011 May 1999 British Energy Annual Rept & Accounts 1998-99 ML20206H1231999-05-0505 May 1999 Illinois Power Co CPS Main CR Simulator Certification Rept U-603210, Monthly Operating Rept for Apr 1999 for Cps,Unit 1.With1999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Cps,Unit 1.With U-603204, Final Part 21 Rept 21-99-003 Re Deficiency in Commercial Grade Dedication Process Used by Circuit Breaker Refurbishment Supplier Trentec for Westinghouse Breaker 1AP05EH.Issue Determined Not Reportable Per 10CFR211999-04-30030 April 1999 Final Part 21 Rept 21-99-003 Re Deficiency in Commercial Grade Dedication Process Used by Circuit Breaker Refurbishment Supplier Trentec for Westinghouse Breaker 1AP05EH.Issue Determined Not Reportable Per 10CFR21 U-603192, Monthly Operating Rept for Mar 1999 for Clinton Power Station,Unit 1.With1999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Clinton Power Station,Unit 1.With U-603182, Part 21 Rept Re Deficiency in Commercial Grade Dedication Process Used by Circuit Breaker Refurbishment Supplier, Trentec.Condition Rept 1-99-01-136 Was Initiated to Track Investigation & Resolution of Issue1999-03-12012 March 1999 Part 21 Rept Re Deficiency in Commercial Grade Dedication Process Used by Circuit Breaker Refurbishment Supplier, Trentec.Condition Rept 1-99-01-136 Was Initiated to Track Investigation & Resolution of Issue U-603176, Monthly Operating Rept for Feb 1999 for Clinton Power Station,Unit 1.With1999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Clinton Power Station,Unit 1.With ML20207F2031999-02-10010 February 1999 Rev 1 to CPS COLR for Reload 6 Cycle 7 ML20202J0181999-02-0303 February 1999 SER Accepting Changes in Quality Assurance Program,Which Continues to Meet Requirements of App B to 10CFR50 U-603144, Monthly Operating Rept for Dec 1998 for Clinton Power Station,Unit 1.With1998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for Clinton Power Station,Unit 1.With U-603223, Illinova Corp 1998 Annual Rept. with1998-12-31031 December 1998 Illinova Corp 1998 Annual Rept. with U-603115, Part 21 Interim Rept 21-98-021 Re Deficiencies in Matl Dedication Process Used by Goulds Pumps in Supplying SR Parts to Npps.Issue Is Not Reportable Under 10CFR21. Dedication Process Did Not Affect Ability of Components1998-12-0404 December 1998 Part 21 Interim Rept 21-98-021 Re Deficiencies in Matl Dedication Process Used by Goulds Pumps in Supplying SR Parts to Npps.Issue Is Not Reportable Under 10CFR21. Dedication Process Did Not Affect Ability of Components U-603124, Monthly Operating Rept for Nov 1998 for Clinton Power Station,Unit 1.With1998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Clinton Power Station,Unit 1.With U-603114, Part 21 Rept 21-98-049 Re W Dhp Circuit Breaker Refurbished by Nuclear Logistics,Inc Which Failed to Operate.Caused by Trip Latch out-of-adjustment & Incorrectly Sized Ratchet Lever Assembly Bushing.Breakers Were Returned to Vendor1998-11-25025 November 1998 Part 21 Rept 21-98-049 Re W Dhp Circuit Breaker Refurbished by Nuclear Logistics,Inc Which Failed to Operate.Caused by Trip Latch out-of-adjustment & Incorrectly Sized Ratchet Lever Assembly Bushing.Breakers Were Returned to Vendor U-603103, Monthly Operating Rept for Oct 1998 for Clinton Power Station,Unit 1.With1998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Clinton Power Station,Unit 1.With U-603101, Special Rept:On 980918,discovered That Triaxial Seismic Accelerometers Had Not Been Properly Calibrated.Caused by Inadequate Calibration Procedure.Calibration to Be Performed off-site1998-10-28028 October 1998 Special Rept:On 980918,discovered That Triaxial Seismic Accelerometers Had Not Been Properly Calibrated.Caused by Inadequate Calibration Procedure.Calibration to Be Performed off-site ML20154F8701998-10-0606 October 1998 Safety Evaluation Authorizing Proposed Alternative to Requirements of OMa-1988,Part 10,Section 4.2.2.3 for 21 Category a Reactor Coolant Sys Pressure Isolation Valves U-603091, Monthly Operating Rept for Sept 1998 for Clinton Power Station,Unit 1.With1998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Clinton Power Station,Unit 1.With ML20153F9871998-09-17017 September 1998 Safety Evaluation Accepting 980225 Proposed Rev 26 to Illinois Power Nuclear Program Qam ML20151U1391998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for Clinton Power Station,Unit 1 ML20237E3991998-08-27027 August 1998 SER Accepting Licensee Response to NRC Bulletin 95-002, Unexpected Clogging of Residual Heat Removal Pump Strainer While Operating in Suppression Pool Cooling Mode, for Clinton Power Station ML20237A1521998-08-0707 August 1998 SER Re Mgt Services Agreement at Clinton Power Station. Approval Under 10CFR50.80 Not Required ML20151Y6591998-07-31031 July 1998 Monthly Operating Rept for July 1998 for Clinton Power Station,Unit 1 U-603033, Part 21 Rept 21-98-039 Re Shrinkage of Medium & High Density Silicone Seals Designed & Installed by Bisco Using Dow Corning Sylgard 170 Matl.Caused by Coefficient of Thermal Expansion.Will Inspect & Rework/Repair Suspected Seals1998-07-20020 July 1998 Part 21 Rept 21-98-039 Re Shrinkage of Medium & High Density Silicone Seals Designed & Installed by Bisco Using Dow Corning Sylgard 170 Matl.Caused by Coefficient of Thermal Expansion.Will Inspect & Rework/Repair Suspected Seals U-603041, Monthly Operating Rept for June 1998 for Clinton Power Station,Unit 11998-06-30030 June 1998 Monthly Operating Rept for June 1998 for Clinton Power Station,Unit 1 ML20151U1501998-06-30030 June 1998 Revised Monthly Operating Rept for June 1998 for Clinton Power Station,Unit 1 U-603023, Monthly Operating Rept for May 1998 for Clinton Power Station,Unit 11998-05-31031 May 1998 Monthly Operating Rept for May 1998 for Clinton Power Station,Unit 1 U-603014, Special Rept:On 980512,lightning Struck Primary Meteorological Monitoring Instrumentation Tower Damaging 60- Meter Wind Speed & Associated Transmuter Circuit Card. Surveillance Testing Performed1998-05-28028 May 1998 Special Rept:On 980512,lightning Struck Primary Meteorological Monitoring Instrumentation Tower Damaging 60- Meter Wind Speed & Associated Transmuter Circuit Card. Surveillance Testing Performed ML20236E7991998-05-26026 May 1998 Final Part 21 Rept Re W Dhp Circuit Breaker Auxillary Switch Operating Assembly Anomalies.Caused by Loss of Breaker Safety Function.Dhp Circuit Will Be Inspected ML20248F3531998-05-21021 May 1998 Part 21 Rept Re Electronic Equipment Repaired or Reworked by Integrated Resources,Inc from Approx 930101-980501.Caused by 1 Capacitor in Each Unit Being Installed W/Reverse Polarity. Policy of Second Checking All Capacitors Is Being Adopted U-603004, Part 21 Rept Re 980107 Determination That Itt Barton Model 580A Series Differential Pressure Indicating Switches Operating Forces Too Low.Manufacturing Sys Allowed Switches to Be Mixed.Evaluation Concludes Issue Not Reportable1998-05-15015 May 1998 Part 21 Rept Re 980107 Determination That Itt Barton Model 580A Series Differential Pressure Indicating Switches Operating Forces Too Low.Manufacturing Sys Allowed Switches to Be Mixed.Evaluation Concludes Issue Not Reportable ML20216A9601998-05-0808 May 1998 Part 21 Rept Re Failure of 12 Volt DC Inverter Power Supply. Caused by Inadequately Sized Output Transistor Pair Combined W/Degraded Capacitors.Licensee Plans to Replace All Output Transistors & Degraded Capacitors U-602995, Part 21 Interim Rept 21-98-021 Re Deficiencies in Matl Dedication Process Used by Goulds Pumps During Use of Portable Metal Analyzer.Util Identified Discrepancies Which Are Acceptable W/Some Exception of Some Replacement Parts1998-05-0505 May 1998 Part 21 Interim Rept 21-98-021 Re Deficiencies in Matl Dedication Process Used by Goulds Pumps During Use of Portable Metal Analyzer.Util Identified Discrepancies Which Are Acceptable W/Some Exception of Some Replacement Parts U-603006, Monthly Operating Rept for Apr 1998 for Clinton Power Station,Unit 11998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for Clinton Power Station,Unit 1 U-602994, Part 21 Rept Re Final Rept 21-98-008,on 980113,reliance Electric Motors Supplied by Rockwell International for Hydrogen Recombiner Cooling Fans Do Not Have nameplate- Specified High Temperature Bearings.Fan Motors Acceptable1998-04-29029 April 1998 Part 21 Rept Re Final Rept 21-98-008,on 980113,reliance Electric Motors Supplied by Rockwell International for Hydrogen Recombiner Cooling Fans Do Not Have nameplate- Specified High Temperature Bearings.Fan Motors Acceptable ML20216B1351998-04-21021 April 1998 Rev 0 to Illinois Power Co Clinton Power Station SVC Design Rept U-602979, Final Part 21 Rept 21-97-059 Re Discrepancies Found During Receipt Insp of Three Refurbished safety-related W Dhp Circuit Breakers.Util Completed Evaluation,Per 10CFR21 & Concludes That Condition Is Not Reportable1998-04-0707 April 1998 Final Part 21 Rept 21-97-059 Re Discrepancies Found During Receipt Insp of Three Refurbished safety-related W Dhp Circuit Breakers.Util Completed Evaluation,Per 10CFR21 & Concludes That Condition Is Not Reportable U-602976, Monthly Operating Rept for Mar 1998 for Clinton Power Station1998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for Clinton Power Station ML20217H5771998-03-27027 March 1998 Safety Evaluation Concluding That No Significant Safety Hazards Introduced at CPS for Net 32% Ampacity Derating Factor for 1 H & 3 H Conduit Fire Barrier Sys & 1 H Cable Tray Fire Barrier Sys.Requests Response Addressing Issue U-602968, Interim Part 21 Rept 21-97-055 Re Westinghouse Dhp Circuit Breaker Auxiliary Switch Operating Assembly Anomalies. Initially Reported on 980116.Util Currently Evaluating Suppliers Response to Questions Re Issue1998-03-24024 March 1998 Interim Part 21 Rept 21-97-055 Re Westinghouse Dhp Circuit Breaker Auxiliary Switch Operating Assembly Anomalies. Initially Reported on 980116.Util Currently Evaluating Suppliers Response to Questions Re Issue U-602960, Part 21 & Deficiency Rept Re Commerical Grade Dedication Program of Sentry Equipment Corp.Initially Reported on 980217.IP Performed an Addl Assessment at Sentry Facility on 980226.Next Rept Will Be Submitted by 9804111998-03-12012 March 1998 Part 21 & Deficiency Rept Re Commerical Grade Dedication Program of Sentry Equipment Corp.Initially Reported on 980217.IP Performed an Addl Assessment at Sentry Facility on 980226.Next Rept Will Be Submitted by 980411 U-602954, Interim Part 21 rept,21-98-008 Re Identification That Bearings Installed in Hydrogen Recombiner B Cooling Fan Motor 0HG04CB Were Not Same as Bearings Specified on Motor Nameplate.Will Complete Evaluation of Issue by 9805131998-03-0909 March 1998 Interim Part 21 rept,21-98-008 Re Identification That Bearings Installed in Hydrogen Recombiner B Cooling Fan Motor 0HG04CB Were Not Same as Bearings Specified on Motor Nameplate.Will Complete Evaluation of Issue by 980513 1999-09-30
[Table view] |
Text
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t i
lilinois Powof Company Clinton Power Station
, P.O Box 678
Tel 217 935-8881 ILLINOIS u-co2189 POMR uv.93(o9-24>te 8E.110c September 24,1993' Docket No. 50-461 10CFR50.36 Document Control Desk Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Follow-Up Special Report on Valid Test Failures of the Division I Diesel Generator at Clinton Power Station (CPS)
Dear Sir:
?
This follow-up Special Report updates the progress of the investigation into the Division I diesel generator test failures that occurred on June 23,1993 and July 21,1993 and which were discussed in Special Reports U-602163 (dated July 23, 1993) and- .
U-602174 ( dated August 20,1993) respectively. As the August 20,1993 Special Report also addressed a Division I diesel generator failure that occurred on August 3,1993, this ,
failure in combination with the June 23 and July 21 failures contributed to a total number ;
of failures such that seven valid failures had occurred in the last 100 valid tests of the Division I diesel generator. This meets the CPS Technical Specification 4.8.1.1.3 '
reporting criterion for providing the additional information recommended by Regulatory l Position C.3.b of Regulatory Guide 1.108. Accordingly, this information is included in this follow-up Special Report.
Sincerely yours, g 7 ),V /
L h d a< L ih Richard F. Phares Director-Licensing .
TAB /CLJE/nis P
cc: NRC Clinton Licensing Project Manager NRC Resident Office, V-690 Regional Administrator, Region III, USNRC lilinois Department of Nuclear Safety r
9310050277 930924 ? i ,
l'"
gDR ADOCK 05000461 /.
PDR h) /hC/ l
j Attachment 1
. to U-602189 Page 1 of 8 Root C:.use Determination / Corrective Actions for June 23 and July 21,1993 Failures i
June 23,1993 Valid Failure As previously stated in Illinois Power (IP) letter /Special Repon U-602163 (dated July 23,1993) the cause of the Division I diesel generator (DGlA) failing to successfully synchronize with its associated safety bus was determined to be the out-of-calibration reverse power relay. The relay was ;
replaced (with a new model), and an analysis of the removed relay was performed by General Physics to determine the cause of the relay failure. The scope of the analysis included the examination of the original GGPS3B relay for physical or electrical defects which could have afTected its operability, and performance of a routine electrical test of the relay to determine its operability.
The results of the examination by General Physics indicated that the relay showed no indications of physical or electrical defects, or wear of the relay which might have contributed to the valid test failure on June 23,1993. It was concluded from the facts of the investigation that since the relay was found out-of-calibration on June 24,1993, and the analysis revealed the relay had no defects, the root cause of the failure was miscalibration of the reverse power relay. Factors contributing to the miscalibration are (1) the test equipment (Multi Amp) that had been used to calibrate the relay was less than state-of-the-art and (2) physical construction of the previous model GGP53B relay made calibration adjustments difficult compared to the new replacement GGP53C relay.
The Multi Amp test equipment is technology from the 1950's that was updated in 1976. The Multi Amp test equipment is manually controlled analog equipment that does not lend itself to being user friendly. Use of the Multi Amp test equipment also requires other external equipment to be connected (i.e., load bank, ammeter, phase shiner, etc.). The newer Doble test equipment is sonware driven, personal computer-based test equipment which is mostly automated and user friendly. Doble test equipment does not require external equipment to be connected for testing. The Doble equipment is more accurate and has better resolution since it is computer driven.
The main difference between the model GGP53B relay and the model GGP53C relay is the physical construction of the lower directional unit. For each model, the voltage bias adjustment and locking nut is on the bottom of the directional unit. On the GGP53B the voltage bias adjusting screw '
and locking nut are countersunk into the bottom of the directional unit thereby limiting easy access to the voltage bias adjustment. However, for the GGP53C relay, the voltage bias adjusting screw and locking nut are not countersunk into the bottom of the directional unit. This allows for easier access and adjustment of the voltage bias. In addition, the GGP53B is no longer available since it is obsolete. I In combination, the factors described above made it possible to calibrate the relay to be marginally acceptable. Although the relay was calibrated according to approved procedures, and the as-leR data was acceptable, the relay could function properly during some synchronizations but not during others, depending on how quickly the diesel was loaded.
Corrective actions for the failure of DGIA due to the reverse power relay on June 23, 1993 have been determined. Resolution of the contributing factors of the miscalibration have been to ,
improve the test equipment by replacing the Multi Amp equipment with the new Doble test equipment and revising the associated test procedures. The need for new procedures and test equipment was
l Attachment
, to U-602189 .i Page 2 of 8 previously recognized. New test equipment has been obtained and the new procedures have been issued for use. All of the procedures received a thorough technical review by Engineering.
In addition to the above actions, each GGP53B reverse power relay will be upgraded (replaced) to the GGP53C relay to allow for easier calibration due to the physical construction of the relay. (This relay is used for each of the emergency generators. Two are also used for the main generator at CPS.) l Four of the five relays onsite have already been replaced, and the last relay will be replaced during the - ;
upcoming refueling outage (scheduled to start September 26,1993). >
r
?
July 21,1993 Valid Failure As stated in IP letter /Special Report U-602174 (dated August 20,1993) the suspected cause of the breaker failing to close was due to degraded contacts within the manual breaker control switch. The !
switch was replaced, subsequently tested, and was inspected for confirmation of the most probable cause of the failure. Testing revealed that when the switch was moved to the closed position, the normally closed 13/14 pull-to-lock contacts would intermittently open thereby preventing the breaker i from closing. Upon disassembly of the manual breaker control switch, it was noted that the 13/14 contacts were severely pitted. This confirms that the 13/14 contacts opened intermittently during recent closing of the manual breaker control switch. IP is continuing to investigate the cause of this problem.
Corrective actions for this event include continued monitoring of the manual breaker control switch using recording instrumentation temporarily connected to the diesel control circuitry.
Monitoring will continue for at least 10 consecutive valid starts in order to assure that no other ,
deficiencies exist in the control circuitry for DGI A. Additionally, the manual breaker control switch for each of Divisions II and III will be replaced during the next scheduled divisional diesel outages. During these outages, the original switches will be inspected and tested in order to verify that the failure of the manual breaker control switch is not generic. Based on the results of the fmdings of the above, further corrective actions will be developed as necessary.
It should be noted that consideration is being given to reclassification of the valid failure which occurred on July 21,1993 pending testing and inspection of the switches removed from the Division II
- and III diesel generators. This is based on the fact that the breaker conuol switch function is part of the synchronizing circuitry and is not required to be operated for automatic operation (starting and loading) of the diesel generators during a loss of ofTsite power or a loss ricoolant accident. If this failure is -
reclassified, this would reduce the number of valid failures in the last 100 stans to 6 valid failures (as of the date of this report).
Additional Information as Recommended I y Reculatorv Guide 1.108 As stated in the IP Special Report dated August 20,1993, the current number of valid failures in the last 100 valid tests of DGl A is seven. Therefore, the additional information recommended by Regulatory Guide 1.108 Position C.3.b (as required by Technical Specification 4.8.1.1.3) is provided below.
Attachment
, to U-602189-Page 3 of 8 Corrective Measures to Increase Diesel Generator Reliability '
The seven valid failures of DGl A which have occurred in the last 100 valid tests occurred on >
April 4,1991 (reference IP Special Report dated May 6,1991), July 17,1992 and August 7,1992 (reference IP Special Report dated August 19,1992); September 21,1992 (reference IP Special Report -
dated October 20,1992); June 23,1993 (reference IP Special Report dated July 23,1993) and July 21, 1993 and August 3,1993 (reference IP Special R.eport dated August 20,1993).
- The DGl A test failure of April 4,1991 was caused by the failure of the output breaker to close when the operator attempted to synchronize the diesel generator with offsite power during a surveillance test. The undervoltage and auxiliary relays were removed, inspected, and recalibrated. The breaker cubicle, control power fuses, and breaker contacts were also inspected. No discrepancies were found.
Since troubleshooting did not reveal a cause for the DGI A failure, the output breaker was racked in, and DGI A was tested with satisfactory results. Additionally, the diesel generator was loaded
- and unloaded a number of times, thus causing the output breaker to be cycled several times. This provided reasonable assurance of the breaker's reliability.
No specific cause for the April 4,1991 breaker failure was ascertained. The May 6,1991 Special Report for this event concluded that the cause may have been a failure of the breaker to completely engage due to a problem with the breaker racking mechanism; but as previously stated, the breaker subsequently functioned properly. Notwithstanding, the racking mechanism was inspected and lubricated for the DGI A output breaker to ensure its proper functioning in the future.
The DGI A failures on July 17,1992 and August 7,1992 were the result of the output breaker failing to close. A comprehensive action plan was developed and troubleshooting was performed to ;
identify the cause of the breaker failure. The root cause of the DGI A output breaker failure to close was determined to be a failure of the truck-operated contacts (TOC) switch Hl. The purpose of this switch is to signal the output breaker closing circuitry that the breaker is racked in. (Closure of the ,
breaker is prevented ifit is not fully racked in.) IP determined that the 1-2 contact pair of the H1 TOC :
switch lost electrical continuity due to (1) slight breaker movement, and/or (2) buildup of oxidation / pitting on the contact surfaces. >
Corrective actions for the July 17 and August 7,1992 failures included replacing the H1 and H2 TOC switches in the DGI A output breaker. The TOC switches in the Division II output breaker cubicle were also replaced, and subsequent inspection of the removed TOC switches indicated no abnormal wear. In addition, the switches which perform a similar function in the Division III output !
breaker cubicle were subsequently inspected and no abnormalities were identified. IP plans to inspect a -
representative sample of TOC switches in similar breaker cubicles in safety-related applications by the end of the upcoming refueling outage. The results of these inspections will be evaluated for further l correc6ve achons.
The September 21,1992 DGI A test failure resulted from the failure of the associated output breaker to close. It was subsequently determined that the root cause of this failure was a bent
Attachment *
, to U-602189 Page 4 of 8 protective cover over the associated anti-pump relay (located within the breaker cubicle). The bent !
cover partially depressed the anti-pump relay plunger so that the contacts operated by the' plunger were >
lightly touching. This resulted in erratic operation of the relay. Also, the bent cover may have cocked ,
the plunger to the side, thus interfering with its operation.
As a result of this failure, a corrective action plan was implemented. The DGI A output breaker [
was replaced with a spare breaker as part of the troubleshooting performed. All of the other Class 1E 4160-volt Westinghouse breakers were inspected for damage to the protective cover, and no similar l conditions were found. Additional inspections of the failed breaker by the mam.facturer did not change i the root cause determination. In addition, a ten-week monitoring program was initiated to monitor the closing circuit of the installed output breaker during surveillance tests of DGI A. No additional failures were observed.
The root cause and corrective actions for the valid failures of DGI A on June 23,1993 and Juiy ;
21,1993 were previously discussed in this report. {
t The August 3,1993 failure ofDGI A was the result of a condition discovered during operational >
rounds by an area Operator. The DGI A B-C phase and A-B phase undervoltage relays (Westinghouse model CV-2) were found with dropped targets that were unable to be reset. Failure of either of these ;
relays, which are part of the permissive-to-close circuitry for the DGI A output breaker, could cause premature closure of the breaker upon receipt of an automatic start signal coincident with a loss of '
offsite power. Troubleshooting determined that the root cause of the undervoltage relay trip _ condition .
was due to the failure of the normally energized telephone coil in the B-C phase undervoltage relay. l The failure was subsequently determined to be age related.
l The corrective action plan for the above included replacing the Division I B-C phase CV-2 relay. ,
The Division 1 A-B phase CV-2 relay and both Division Il_CV-2 relays will be replaced during the next outage for each of these divisions. It was confirmed that these relays are not used in a similar function for the Division Ill diesel generator. The remaining safety-related relays that utilize telephone coils in ,
similar configurations at CPS are normally de-energized, and similar failures are not expected for these ;
coils. A preventive maintenance task has been initiated to replace the Division I and II A.-B and B-C phase CV-2 relays at seven-year intervals. :
Assessment of the Existine Heliability of Electric Power to Eneincered Safety Feature Equinment The IP electrical system provides a diversity of power supplies. The 138 kV offsite power I system provides power to CPS via one transmission line from the Clinton Route 54 Substation which effectively connects CPS to the Illinois Power Company grid. Electrical power can be fed to this substation through a line from the south Bloomington substation or through a line from the north Decatur substation, or both. The line from the Clinton Route 54 substation terminates directly (through a circuit switcher) at the station Emergency Reserve Auxiliary Transformer, which transforms the electrical power to 4160-volt auxiliary bus voltage.
Attachment
, to U-602189 j
. Page 5 of 8 l The 345. kV offsite power system provides power to CPS via three separate transmission lines.
These lines connect CPS to the Illinois Power Company grid at the Brokaw, Rising, and Latham l Substations. All three lines terminate at the station switchyard ring bus which feeds the Reserve -l Auxiliary Transformer (through a circuit switcher), which in turn transforms the electrical power to 6900 volt and 4160 volt auxiliary bus voltages. Only one 138 kV and one 345 kV line are required to be available by the CPS Technice 5pecifications. :
There are three diesel generator units on site that automatically provide emergency power in the ;
unlikely event that the offsite AC power sources described above become unavailable. Diesel generator 1 A (DGI A) supplies power to Division I electrical equipment, diesel generator IB (DGlB) supplies ;
power to Division II electrical equipment, and diesel generator IC (DGlC) supplies power to Division III electrical equipment (primarily the High Pressure Core Spray System). In supporting safe shutdown i of the facility in the event of an emergency or accident, Division I is redundant to Division 11.
Based on plant operation to date, overall reliability of electric power for engineered-safety feature equipment has proved to be very high when both onsite and offsite sources are considered.
Offsite source availability has historically been especially high. All events to date which impacted offsite source availability are briefly summarized below.
With respect to the offsite transmission lines, CPS has never experienced a complete loss of ofTsite power. Since CPS began operation, the 138 kV line has been 100% available (except for planned maintenance). 345 kV power has also never been lost, though outages of at least one (or two) of the three 345 kV lines have occurred. A very short-term interruption (approximately 4 seconds) occurred in 1989 for one of the 345 kV lines. Two more events which occurred recently are described below.
On June 8,1993, high winds downed a ponion of one of the 345 kV transmission lines to the station switchyard (line 4571 to Latham substation). Approximately 17 miles of supporting stmetures collapsed between the Latham substation and the double-circuit tower east of Maroa. The remaining two 345 kV transmission lines to the CPS switchyard remained in service during the severe weather. '
(The 138 kV offsite circuit was also unafrected.) Repairs to this line have been completed , and the line was restored to service at 1840 on September 22,1993.
On August 4,1993, one of the remaining two 345 kV transmission lines in sersice to the CPS switchyard (line 4535 to Brokaw substation) experienced a momentary fault causing the plant to. isolate to the remaining transmission line. During this event, a voltage transient occurred that resulted in generator terminal voltage declining to approximately 70%. The entire event lasted for a duration of about 7 seconds. This resulted in some plant equipment tripping but the equipment was quickly ,
restored to service by plant operators, thus preventing the plant from tripping off-line. (A similar fault occurred on August 19, 1993 without a voltage transient occurring.) An investigation is ongoing to determine the cause of this transient.
One other event invohing a switchyard component occun ed during a plant outage that began on l November 11,1988 due to a failure of the C-phase main power transformer. On November 14,1988 arcing was observed on a station switchyard circuit switcher (4538) associated with the reserve auxiliary '
transformer (RAT). Load was successfully shedded or transferred from the RAT, and the RAT was i l
I
. Attachment
. to U-602189
- Page 6 of 8' disconnected from the station switchyard ring bus to facilitate inspection of the circuit switcher.
Inspection of the circuit switcher revealed that the blade disconnect hinge assembly on the B phase, line .
side, was damaged. Following repairs, the RAT was re-energized, approximately 14-1/2 hours after it was removed from service. This event did not result in any unplanned actuation of any engineered safety features. Periodic infrared thermography is now performed on the circuit switcher connections to identify degradation before it becomes severe or damage occurs.
Basis For Continued Plant Operation As described previously, Illinois Power electrical system design provides a diversity of offsite sources for supplying power to the safety-related equipment needed to achieve and maintain the plant in a safe shW,wn condition. These power supplies consist of(1) the 138 kV offsite transmission line from the daton Route 54 Substation which supplies the station Emergency Reserve Auxiliary Transformer (ERAT), and (2) the station switch yard ring bus which supplies the Reserve Auxiliary Transformer (RAT). The Clinton Route 54 Substation can be fed by two separate lines from two separate substations. The ERAT is sized to carry all the safety-related loads of CPS. The station switchyard ring bus can be fed by three separate 345 kV lines which originate from three separate substations. The RAT is sized to carry all the stations loads (safety and non-safety related).
In the event of a complete loss of offsite power, each of three diesel generators supplies onsite emergency power to its respective division of safety-related equipment. As also noted previously, with respect to supporting safe shutdown of the facility in the event of an emergency or accident, Division I is redundant to Division II, while Division III is primarily associated with the high pressure core spray system.
Test history for the Division II and Division III diesel generators indicates that these onsite emergency power sources are highly reliable. DGIC has never experienced a valid test failure since CPS began operation. Only five valid test failures have been recorded for DG1B, and DGlB has only experienced three valid failures in the last 100 valid tests performed.
Based on the high reliability of offsite power supply system for CPS, the redundancy built into the CPS design to accommodate a single-failure, the proven reliability of the Division II and III diesel generators, and in light of the corrective action taken for the recent DGl A test failures,. continued plant operation is justified.
Summary of Testine of the Diesel Generators DGI A Of the last 100 valid tests performed for DGl A, seven have resulted in valid failures. These valid failures were previously discussed in detail. Additionally, 39 non-valid tests were conducted during this testing period in order to perform troubleshooting and post-maintenance testing. One of these non-valid tests resulted in a non-valid failure on January 9,1992. This non-valid failure was reported in IP letter /Special Report U-601931 (dated February 5,1992) and was the result of a reverse power trip during diesel generator synchronization. This trip was caused by operator error during closure of the output breaker.
Attachment
. to U-602189 Page 7 of 8 Testing of DGIA has been accomplished at the frequency required by the CPS Technical Specifications. The required frequency of surveillance testing of the diesel generators at CPS is specified by Technical Specification Table 4.8.1.1.2-1. The frequency of testing for a given diesel generator is determined by the demonstrated reliability of that diesel generator. Technical Specification Table 4.8.1.12-1 states that the diesel generator testing frequency shall be at least once per 31 days if the number of failures in the last 20 valid tests performed is one or less and in the last 100 valid tests performed is four or less. The surveillance frequency must be increased to at least once per seven days if the number of failures in the last 20 valid tests performed is two or more nr if the number of failures in the last 100 valid tests performed is five or more. Footnote "**" of Technical Specification Table 4.8.1.1.2-1 further states that the seven-day surveillance interval must be maintained until seven consecutive failure-free demands have been performed and the number of failures in the last 20 valid tests performed has been reduced to one or less.
The testing period for the last 100 valid tests of DGIA began on May 21,1990. At that time, 89 valid tests for DGl A had been performed since receipt of the CPS Operating License. As of May 21,1990, DGI A had experienced zero valid failures in the last 20 valid tests and eight valid failures out of the previously performed 89 valid tests. DGl A was thus being tested weekly at that time. The criterion for resuming monthly testing was subsequently met on September 27,1990.
The valid failure on April 4,1991 constituted the first valid failure in the last 20 valid tests and the sixth valid failure in the last 100 valid tests.' As a result, the testing frequency required by Technical Specification Table 4.8.1.1.2-1 for DGI A was again increased to weekly. By May 16,1991, seven consecutive failure-free tests had been performed, and the testing frequency required by Technical Specification Table 4.8.1.1.2-1 for DGl A was returned to monthly.
The valid failure on July 17,1992 constituted the first valid failure in the last 20 valid tests and the seventh valid failure in the last 100 valid tests. As a result, the testing frequency required by Technical Specification Table 4.8.1.1.2-1 for DGl A was again increased to weekly. The valid failure l on August 7,1992 was the second valid failure in the last 20 valid tests and the eighth valid failure in .
the last 100 valid tests. As a result, the testing frequency required by Technical Specification Table 4.8.1.1.2-1 for DGI A remained at weekly.
Another valid failure of DGI A was experienced on September 21,1992. DGIA had, at that time, experienced six valid failures in the last 100 valid tests performed, and three valid failures in the last 20 valid tests performed. Weekly testing of DGI A testing frequency was thus continued. Monthly testing was resumed after completion of a successful test on November 30, 1992 when seven consecutive failure-free demands had been performed and the number of failures in the last 20 valid tests ,
had been reduced to one. I The next valid test failure for DGI A did not occur until June 23,1993 (which was previously discussed in detail in this report). DGI A had then experienced four valid failures in the last 100 valid tests performed. This test failure was initially regarded as a non-valid failure, but as discussed in IP l letter /Special Report U-602174 (dated August 20, 1993) this failure was later reclassified as a valid failure. Based on IP's initial classification of the test failure however, monthly testing was continued. In I
q 1
.- Attachment
.-- to U-602189 Page 8 of 8 accordance with CPS Technical Specification Table 4.8.1.1.2-1, DGI A continued to be tested at least once per 31 days.
With the occurrence of the DGI A test failure that occurred on July 21, 1993, the Technical Specification criterion for increased testing had been met, and the DGI A testing frequency was increased to weekly. With the reclassification of the June 23,1993 failure (from non-valid to valid), the July 21,1993 valid failure was the sixth valid failure in the last 100 valid tests for DGl A, and the ;
second valid failure in the last 20 valid tests for DGI A. The subsequent August 3,1993 valid failure -
was thus the seventh valid failure in the last 100 valid tests for DGl A and was also the third valid failure in the last 20 valid tests for DGI A.
As of September 20,1993 weekly testing of DGI A continues, and eleven valid tests have been ,
completed for DGI A since the August 3,1993 failure. Assuming no new failures are experienced, IP plans to resume monthly testing when five more weekly valid tests are completed. At that time more than seven consecutive failure-free demands will have been performed and the number of failures will be-reduced to less than two in the last 20 valid tests. i in summary, as can be seen from the above discussion, the surveillance testing for DGI A has been conducted in accordance with the frequencies required by Technical Specification Table -
4.8.1.1.2-1.
s i
)
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