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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML17355A3891999-07-20020 July 1999 LER 99-001-00:on 990623,manual Rt from 100% Power Following Multiple Control Rod Drops Was Noted.Caused by Manual Action Taken by Reactor Control Operator.Inspected & Repaired Stationary Gripper Regulating Cards.With 990720 Ltr ML17354B1921998-11-18018 November 1998 LER 98-007-00:on 981020,containment Purge Supply,Valve Opened Wider than TS Limit.Caused by Improper Setting of Mechanical Stops.Incorporated Improved Standard Method of Measuring Angular Valve Position Into Sp.With 981118 Ltr ML17354B1361998-10-16016 October 1998 LER 98-004-00:on 980921,automatic Reactor Trip Occurred. Caused by Inadequate re-correlation of Intermediate Range Neutron Flux Instrumentation Reactor Trip Bistable. Enhanced Applicable Plant Procedures.With 981016 Ltr ML17354B0341998-07-15015 July 1998 LER 98-003-00:on 980619,discovered That Auxiliary Feedwater Sys Was Inoperable Due to Inadequate Inservice Testing of Valves.Caused by Misunderstanding of Testing Criteria.Util Revised Procedures & Verified Operability of Valves ML17354A9841998-06-18018 June 1998 LER 97-007-01:on 970730,automatic Reactor Trip Occurred Due to Closure of B Msiv.Caused by Failed BFD22S Relay.Six Relays on 3A,3B & 3C MSIVs Were Replaced & Implemented Plant Change to Disable Electronic Trip Function on 3 AFW Pumps ML17354A9741998-06-0909 June 1998 LER 98-002-00:on 980513,discovered Potential LOCA-initiated Electrical Fault Which Places ECCS Outside Design Basis. Caused by Inadequate Review of Effect on non-safety Circuit failures.Re-powered PC-*-600A Relays ML17354A8511998-03-24024 March 1998 LER 97-009-01:on 971114,discovered That CR Console Switch for 3B Sgfp Was Not in Start Position.Caused by Inadequate Procedural Guidance.Revised Procedures 3/4-OP-074,informed Personnel of Event & Performed Walkdown of CR ML17354A8441998-03-18018 March 1998 LER 98-001-00:on 980216,manual Reactor Trip Occurred Due to Loss of Turbine Control Oil Pressure W/Steam Leak in Auxiliary Feedwater Steam Supply Piping.Auxiliary Governor Maint Instructions Will Be revised.W/980318 Ltr ML17354A7361997-12-12012 December 1997 LER 97-009-01:on 971114,identified That CR Console Switch for 3B SG Feedwater Pump Was Not in Start Position.Caused by Inadequate Procedural Guidance.Procedures 3/4-OP-074,SGFP Were revised.W/971212 Ltr ML17354A6801997-10-0808 October 1997 LER 97-008-00:on 970909,containment Sump Debris Screens Outside Design Basis Due to Stress Damage Was Discovered. Caused by Inadequate Procedural Guidance & Personnel Error. Discrepancies Found on Screens corrected.W/971008 Ltr ML17354A6121997-08-29029 August 1997 LER 97-007-00:on 970730,automatic Reactor Trip Occurred. Caused by Closure of B Main Steam Isolation Valve.Failed W Relay & Equivalent Relays Were replaced.W/970829 Ltr ML17354A6081997-08-18018 August 1997 LER 97-006-00:on 970722,manual Reactor Trip Occurred Due to Failed Rod Control Power Supplies.Replaced Twelve Power Supplies in Rod Control Logic & Power cabinets.W/970818 Ltr ML17354A5801997-07-14014 July 1997 LER 97-005-00:on 970618,RCP Oil Collection Sys Was Found Outside Design Basis.Caused Because Design Did Not Consider Component Parts to Be Potential Leakage Sources.Entire RCP Oil Collection Sys Was reviewed.W/970714 Ltr ML17354A5141997-05-22022 May 1997 LER 97-002-00:on 970423,automatic Reactor Tripped.Caused by Actuation of Turbine Overspeed Protection Circuit. Administrative Procedures Governing Inadequate Work Controls Will Be Revised to Capture Lessons learned.W/970522 Ltr ML17354A5061997-05-0909 May 1997 LER 97-003-00:on 970410,mode Changed W/O Meeting Requirements of TS 3.0.4 Due to Inadequate Procedural Guidance.Night Order Was Issued to Inform Personnel That S/G Blowdown Keylock Switches Were Left in drain.W/970509 Ltr ML17354A5051997-05-0909 May 1997 LER 97-004-00:on 970411,auxiliary Feedwater Automatic Start Upon Trip of All Main Feedwater Pumps,Occurred.Caused by Mispositioned Valve Closing.Valves Listed as Inappropriately Positioned Were repositioned.W/970509 Ltr ML17354A4781997-04-25025 April 1997 LER 97-001-00:on 970327,ECCS Recirculation Loop Leakage Was Found to Be in Condition Outside Design Basis Due to Gasket Movement During Installation During Spring 1966 Reassembly. Gasket Replaced & Pump tested.W/970425 Ltr ML17354A4581997-03-28028 March 1997 LER 97-002-00:on 970303,manual Reactor Trip Following Rod Control Urgent Failure Alarm Occurred.Caused by Phase Failure Detection on Stationary a Circuits of 2BD Rod Control Cabinet.Air Conditioning replaced.W/970328 Ltr ML17354A4511997-03-26026 March 1997 LER 97-001-00:on 970118,missed Surveillance on CR Position Verification Occurred Due to Inoperable Rod Deviation Monitor.Faulty Circuit Common Connection Was Corrected & Rdm Operability Was restored.W/970326 Ltr ML17354A4061997-02-0303 February 1997 LER 96-004-03:on 970107,identified Three Instances of Inadequate Surveillance Testing.Caused by Inadequate Surveillance Procedures.Surveillance Procedures Revised ML17354A3771996-12-27027 December 1996 LER 96-012-00:on 961204,determined Containment Average Temp Being Determined Based on Only Two Temp Elements Instead of Three as Required by Tss.Caused by Log Only Requiring One Entry.Log revised.W/961227 Ltr ML17354A3261996-11-0606 November 1996 LER 96-011-00:on 961009,potential for Overpressurizing Post Accident Containment Vent Filter Housings Occurred.Caused by Improper Change Mgt.Monitoring Sys Operating Procedures revised.W/961106 Ltr ML17354A3071996-10-22022 October 1996 LER 96-010-00:on 960924,manual Reactor Shutdown Occurred. Caused by Failed Rod Control Sys Regulation Card in 2AC Power cabinet.2AC Power Cabinet DC Power Supplies,Cabling & Connectors checked.W/961022 Ltr ML17353A8711996-08-27027 August 1996 LER 96-009-00:on 960729,failed to Reflect Heavy Load Design Info in Procedural Controls.Caused by Failure to Incorporate 1982 Procedure Changes.Suspended Lifting of Heavy Loads & Took Turbine Bldg Crane OOS.W/960827 Ltr ML17353A7411996-06-18018 June 1996 LER 96-008-00:on 960521,surveillance Method for Testing Emergency Diesel Generators (EDG) Determined Inadequate. Caused by Personnel Error.All Four EDGs Rapid Start Tested & EDG Surveillance Procedures modified.W/960618 Ltr ML17353A7401996-06-18018 June 1996 LER 96-004-02:on 960524,identified Inadequate Surveillance Testing.Caused by Inadequate Surveillance Procedures.Entered Tech Spec Statements,Tested Required Instruments Functions & Revised Plant procedure.W/960618 Ltr ML17353A6901996-05-13013 May 1996 LER 96-004-01:on 960220,identified Potential Tech Spec non-compliance Associated W/Surveillance Testing of AFW Actuation Circuitry on Sg.Caused by Inadequate Surveillance Procedures.Procedures revised.W/960513 Ltr ML17353A6741996-05-0606 May 1996 LER 96-001-00:on 960409,manual Rt Occurred Due to Turbine Governer Control Oil Perturbation.Disassembled & Inspected Governor Valve for Cleanliness & Corrosion products.W/960506 Ltr ML17353A6651996-04-29029 April 1996 LER 96-007-00:on 960329,inadvertent ESF Actuation Occurred During Refueling Outage Due to Cognitive Personnel Error. Personnel Involved Counseled & Integrated Safeguards Test Procedures Being revised.W/960429 Ltr ML17353A6601996-04-25025 April 1996 LER 96-006-00:on 960327,manual Rt Occurred Due to 3C Transformer Lockout & Loss of 3B SG Mfp.Replaced SAM Timer Relay in 3AC16.W/960425 Ltr ML17353A6491996-04-23023 April 1996 LER 96-005-00:on 960326,certain Safety Injection Accumulator Filled Evolutions Resulted in cross-tied Configuration.C/A: Night Order Written & Operations Procedure 3/4-OP-064 revised.W/960423 Ltr ML17353A6051996-03-18018 March 1996 LER 96-003-00:on 960222,two Arpi Inoperable & TS 3.0.3 Entered.Proposed License Amend Submitted to Revise Allowed Misalignment from +/-12 Steps to =/-18 Steps Between Arpi & Dpi at Less than 90% power.W/960318 Ltr ML17353A6041996-03-18018 March 1996 LER 96-004-00:on 960220,surveillance Testing of AFW Actuation Circuitry Was Inadequate.Caused by Inadequate Surveillance Procedures.Tested Untested Portions of Actuation Logic for AFW Automatic Start signal.W/960318 Ltr ML17353A5861996-03-0606 March 1996 LER 96-002-00:on 960209,automatic Turbine Trip/Rt Occurred Due to High SG Level.Caused by Personnel Error.Replaced Both Hinge Pins on B Sgfp Discharge Check valve.W/960306 Ltr ML17353A5761996-03-0101 March 1996 LER 96-001-00:on 960131,intake CWS Flow Rates Found W/ Potential to Be Less than Required by Design Basis.Caused by Influx of Aquatic Grass & Algae Onto Basket Strainers of Icw Flow Path.Mechanically Cleaned strainers.W/960301 Ltr ML17353A4451995-11-0909 November 1995 LER 95-007-00:on 951017,manual Rt Occurred Following Drop of Four Control Rods.Caused by Water Intrusion Into Rod Control Power Cabinet 2BD.Inspected Control Power Cabinet 2BD for Other Water damage.W/951109 Ltr ML17353A4241995-10-12012 October 1995 LER 95-006-00:on 950913,analysis Showed That CCW Exchangers Susceptible to Damage Due to flow-induced Vibration.Ccw Sys Has Been Flow Balanced to Closer tolerances.W/951012 Ltr ML17353A3601995-09-13013 September 1995 LER 95-005-00:on 950818,containment Pressure Testing Procedure Resulted in Inhibiting Both Trains of Containment Pressure from Initiated Esf.Revised Procedure to Require Testing of Each Train separately.W/950913 Ltr ML17353A2951995-07-17017 July 1995 LER 94-005-02:on 941103,both Units Outside Design Basis Due to Design Defect in Safeguards Bus Sequencer Test Logic. Resumed Monthly Manual Testing of Sequencer ML17352B1581995-05-0505 May 1995 LER 95-004-00:on 950407,unit Being Shutdown to Investigate Recurring non-urgent Failure Alarms from Redundant Rod Control Power Supplies.Reactor Manually Tripped.All Four PS-3 Power Supplies replaced.W/950505 Ltr ML17352B1181995-04-0707 April 1995 LER 95-003-00:on 950309,intake Cooling Water Flow Rate Through CCW Heat Exchangers Fell Below Assumed Design Basis. Caused by an Influx of Aquatic Grass & Algae Onto Basket Strainers.Strainers cleaned.W/950407 Ltr ML17352B0701995-03-13013 March 1995 LER 95-002-00:on 950215,inadequate Definition of Loops Filled Resulted in Units in Condition Prohibited by Ts. Issued TS Position Statement to Define Term Loops Filled as Used in TS 6.4.1.1.4.W/950313 Ltr ML17352B0321995-02-0909 February 1995 LER 94-005-01:on 941103,design Defect Found in Safeguards Bus Sequencer Test Logic,Placing Facility Outside Design Basis.Design Mods to Eliminate Software Logic Problems Will Be Implemented During Next Refueling outages.W/950209 Ltr ML17352B0101995-01-20020 January 1995 LER 94-006-00:on 941226,C Main Feedwater Control Valve Failed Closed,Causing Reactor & Turbine Trips.Caused by Loose Screw Terminal Connection.I/P Transducers Replaced W/ New Model W/Different Design Wire connection.W/950120 Ltr ML17352A9511994-12-13013 December 1994 LER 94-006-00:on 941130,Unit 4 Tripped Automatically.Caused by Failure of Flexible Link Connection Between Main Generator B Phase Bus & Associated Isolated Phase Bus Bar. All Bolts on Flexible Link checked.W/941213 Ltr ML17352A8871994-11-10010 November 1994 LER 94-005-00:on 941103,design Defect in Safeguards Bus Sequencer Test Logic Places Both Units Outside Design Basis. Caused by 3A Sequencer Failed to Respond as Expected to Opposite Unit SI signal.W/941110 Ltr ML17352A8851994-11-10010 November 1994 LER 94-004-00:on 941103,Unit 3 Outside Design Basis Due to Two of Three Required Safety Injection Pumps Inoperable. Control Switches for 3A & 3B Safety Injection Pumps Immediately Returned to automatic.W/941110 Ltr ML17352A8421994-10-21021 October 1994 LER 94-004-00:on 940923,Unit 4 Tripped Automatically from Rated Power.Caused by Faulty Regulator Transistor.Faulty Backup Power Supply Replaced & Maint History for Power Supplies reviewed.W/941021 Ltr ML17352A8431994-10-20020 October 1994 LER 94-005-00:on 940924,Unit 4 Manually Tripped.Caused by Manual Actuation.Light Bulb & Socket replaced.W/941020 Ltr ML17352B1671994-08-16016 August 1994 LER 94-003-00:on 940720 & 21,util Discovered That Several Required Valve Stroke Time Surveillances Had Not Been Performed.Caused by Personnel Error.Personnel Reassigned & Procedures and Surveillance Tracking Software Enhanced 1999-07-20
[Table view] Category:RO)
MONTHYEARML17355A3891999-07-20020 July 1999 LER 99-001-00:on 990623,manual Rt from 100% Power Following Multiple Control Rod Drops Was Noted.Caused by Manual Action Taken by Reactor Control Operator.Inspected & Repaired Stationary Gripper Regulating Cards.With 990720 Ltr ML17354B1921998-11-18018 November 1998 LER 98-007-00:on 981020,containment Purge Supply,Valve Opened Wider than TS Limit.Caused by Improper Setting of Mechanical Stops.Incorporated Improved Standard Method of Measuring Angular Valve Position Into Sp.With 981118 Ltr ML17354B1361998-10-16016 October 1998 LER 98-004-00:on 980921,automatic Reactor Trip Occurred. Caused by Inadequate re-correlation of Intermediate Range Neutron Flux Instrumentation Reactor Trip Bistable. Enhanced Applicable Plant Procedures.With 981016 Ltr ML17354B0341998-07-15015 July 1998 LER 98-003-00:on 980619,discovered That Auxiliary Feedwater Sys Was Inoperable Due to Inadequate Inservice Testing of Valves.Caused by Misunderstanding of Testing Criteria.Util Revised Procedures & Verified Operability of Valves ML17354A9841998-06-18018 June 1998 LER 97-007-01:on 970730,automatic Reactor Trip Occurred Due to Closure of B Msiv.Caused by Failed BFD22S Relay.Six Relays on 3A,3B & 3C MSIVs Were Replaced & Implemented Plant Change to Disable Electronic Trip Function on 3 AFW Pumps ML17354A9741998-06-0909 June 1998 LER 98-002-00:on 980513,discovered Potential LOCA-initiated Electrical Fault Which Places ECCS Outside Design Basis. Caused by Inadequate Review of Effect on non-safety Circuit failures.Re-powered PC-*-600A Relays ML17354A8511998-03-24024 March 1998 LER 97-009-01:on 971114,discovered That CR Console Switch for 3B Sgfp Was Not in Start Position.Caused by Inadequate Procedural Guidance.Revised Procedures 3/4-OP-074,informed Personnel of Event & Performed Walkdown of CR ML17354A8441998-03-18018 March 1998 LER 98-001-00:on 980216,manual Reactor Trip Occurred Due to Loss of Turbine Control Oil Pressure W/Steam Leak in Auxiliary Feedwater Steam Supply Piping.Auxiliary Governor Maint Instructions Will Be revised.W/980318 Ltr ML17354A7361997-12-12012 December 1997 LER 97-009-01:on 971114,identified That CR Console Switch for 3B SG Feedwater Pump Was Not in Start Position.Caused by Inadequate Procedural Guidance.Procedures 3/4-OP-074,SGFP Were revised.W/971212 Ltr ML17354A6801997-10-0808 October 1997 LER 97-008-00:on 970909,containment Sump Debris Screens Outside Design Basis Due to Stress Damage Was Discovered. Caused by Inadequate Procedural Guidance & Personnel Error. Discrepancies Found on Screens corrected.W/971008 Ltr ML17354A6121997-08-29029 August 1997 LER 97-007-00:on 970730,automatic Reactor Trip Occurred. Caused by Closure of B Main Steam Isolation Valve.Failed W Relay & Equivalent Relays Were replaced.W/970829 Ltr ML17354A6081997-08-18018 August 1997 LER 97-006-00:on 970722,manual Reactor Trip Occurred Due to Failed Rod Control Power Supplies.Replaced Twelve Power Supplies in Rod Control Logic & Power cabinets.W/970818 Ltr ML17354A5801997-07-14014 July 1997 LER 97-005-00:on 970618,RCP Oil Collection Sys Was Found Outside Design Basis.Caused Because Design Did Not Consider Component Parts to Be Potential Leakage Sources.Entire RCP Oil Collection Sys Was reviewed.W/970714 Ltr ML17354A5141997-05-22022 May 1997 LER 97-002-00:on 970423,automatic Reactor Tripped.Caused by Actuation of Turbine Overspeed Protection Circuit. Administrative Procedures Governing Inadequate Work Controls Will Be Revised to Capture Lessons learned.W/970522 Ltr ML17354A5061997-05-0909 May 1997 LER 97-003-00:on 970410,mode Changed W/O Meeting Requirements of TS 3.0.4 Due to Inadequate Procedural Guidance.Night Order Was Issued to Inform Personnel That S/G Blowdown Keylock Switches Were Left in drain.W/970509 Ltr ML17354A5051997-05-0909 May 1997 LER 97-004-00:on 970411,auxiliary Feedwater Automatic Start Upon Trip of All Main Feedwater Pumps,Occurred.Caused by Mispositioned Valve Closing.Valves Listed as Inappropriately Positioned Were repositioned.W/970509 Ltr ML17354A4781997-04-25025 April 1997 LER 97-001-00:on 970327,ECCS Recirculation Loop Leakage Was Found to Be in Condition Outside Design Basis Due to Gasket Movement During Installation During Spring 1966 Reassembly. Gasket Replaced & Pump tested.W/970425 Ltr ML17354A4581997-03-28028 March 1997 LER 97-002-00:on 970303,manual Reactor Trip Following Rod Control Urgent Failure Alarm Occurred.Caused by Phase Failure Detection on Stationary a Circuits of 2BD Rod Control Cabinet.Air Conditioning replaced.W/970328 Ltr ML17354A4511997-03-26026 March 1997 LER 97-001-00:on 970118,missed Surveillance on CR Position Verification Occurred Due to Inoperable Rod Deviation Monitor.Faulty Circuit Common Connection Was Corrected & Rdm Operability Was restored.W/970326 Ltr ML17354A4061997-02-0303 February 1997 LER 96-004-03:on 970107,identified Three Instances of Inadequate Surveillance Testing.Caused by Inadequate Surveillance Procedures.Surveillance Procedures Revised ML17354A3771996-12-27027 December 1996 LER 96-012-00:on 961204,determined Containment Average Temp Being Determined Based on Only Two Temp Elements Instead of Three as Required by Tss.Caused by Log Only Requiring One Entry.Log revised.W/961227 Ltr ML17354A3261996-11-0606 November 1996 LER 96-011-00:on 961009,potential for Overpressurizing Post Accident Containment Vent Filter Housings Occurred.Caused by Improper Change Mgt.Monitoring Sys Operating Procedures revised.W/961106 Ltr ML17354A3071996-10-22022 October 1996 LER 96-010-00:on 960924,manual Reactor Shutdown Occurred. Caused by Failed Rod Control Sys Regulation Card in 2AC Power cabinet.2AC Power Cabinet DC Power Supplies,Cabling & Connectors checked.W/961022 Ltr ML17353A8711996-08-27027 August 1996 LER 96-009-00:on 960729,failed to Reflect Heavy Load Design Info in Procedural Controls.Caused by Failure to Incorporate 1982 Procedure Changes.Suspended Lifting of Heavy Loads & Took Turbine Bldg Crane OOS.W/960827 Ltr ML17353A7411996-06-18018 June 1996 LER 96-008-00:on 960521,surveillance Method for Testing Emergency Diesel Generators (EDG) Determined Inadequate. Caused by Personnel Error.All Four EDGs Rapid Start Tested & EDG Surveillance Procedures modified.W/960618 Ltr ML17353A7401996-06-18018 June 1996 LER 96-004-02:on 960524,identified Inadequate Surveillance Testing.Caused by Inadequate Surveillance Procedures.Entered Tech Spec Statements,Tested Required Instruments Functions & Revised Plant procedure.W/960618 Ltr ML17353A6901996-05-13013 May 1996 LER 96-004-01:on 960220,identified Potential Tech Spec non-compliance Associated W/Surveillance Testing of AFW Actuation Circuitry on Sg.Caused by Inadequate Surveillance Procedures.Procedures revised.W/960513 Ltr ML17353A6741996-05-0606 May 1996 LER 96-001-00:on 960409,manual Rt Occurred Due to Turbine Governer Control Oil Perturbation.Disassembled & Inspected Governor Valve for Cleanliness & Corrosion products.W/960506 Ltr ML17353A6651996-04-29029 April 1996 LER 96-007-00:on 960329,inadvertent ESF Actuation Occurred During Refueling Outage Due to Cognitive Personnel Error. Personnel Involved Counseled & Integrated Safeguards Test Procedures Being revised.W/960429 Ltr ML17353A6601996-04-25025 April 1996 LER 96-006-00:on 960327,manual Rt Occurred Due to 3C Transformer Lockout & Loss of 3B SG Mfp.Replaced SAM Timer Relay in 3AC16.W/960425 Ltr ML17353A6491996-04-23023 April 1996 LER 96-005-00:on 960326,certain Safety Injection Accumulator Filled Evolutions Resulted in cross-tied Configuration.C/A: Night Order Written & Operations Procedure 3/4-OP-064 revised.W/960423 Ltr ML17353A6051996-03-18018 March 1996 LER 96-003-00:on 960222,two Arpi Inoperable & TS 3.0.3 Entered.Proposed License Amend Submitted to Revise Allowed Misalignment from +/-12 Steps to =/-18 Steps Between Arpi & Dpi at Less than 90% power.W/960318 Ltr ML17353A6041996-03-18018 March 1996 LER 96-004-00:on 960220,surveillance Testing of AFW Actuation Circuitry Was Inadequate.Caused by Inadequate Surveillance Procedures.Tested Untested Portions of Actuation Logic for AFW Automatic Start signal.W/960318 Ltr ML17353A5861996-03-0606 March 1996 LER 96-002-00:on 960209,automatic Turbine Trip/Rt Occurred Due to High SG Level.Caused by Personnel Error.Replaced Both Hinge Pins on B Sgfp Discharge Check valve.W/960306 Ltr ML17353A5761996-03-0101 March 1996 LER 96-001-00:on 960131,intake CWS Flow Rates Found W/ Potential to Be Less than Required by Design Basis.Caused by Influx of Aquatic Grass & Algae Onto Basket Strainers of Icw Flow Path.Mechanically Cleaned strainers.W/960301 Ltr ML17353A4451995-11-0909 November 1995 LER 95-007-00:on 951017,manual Rt Occurred Following Drop of Four Control Rods.Caused by Water Intrusion Into Rod Control Power Cabinet 2BD.Inspected Control Power Cabinet 2BD for Other Water damage.W/951109 Ltr ML17353A4241995-10-12012 October 1995 LER 95-006-00:on 950913,analysis Showed That CCW Exchangers Susceptible to Damage Due to flow-induced Vibration.Ccw Sys Has Been Flow Balanced to Closer tolerances.W/951012 Ltr ML17353A3601995-09-13013 September 1995 LER 95-005-00:on 950818,containment Pressure Testing Procedure Resulted in Inhibiting Both Trains of Containment Pressure from Initiated Esf.Revised Procedure to Require Testing of Each Train separately.W/950913 Ltr ML17353A2951995-07-17017 July 1995 LER 94-005-02:on 941103,both Units Outside Design Basis Due to Design Defect in Safeguards Bus Sequencer Test Logic. Resumed Monthly Manual Testing of Sequencer ML17352B1581995-05-0505 May 1995 LER 95-004-00:on 950407,unit Being Shutdown to Investigate Recurring non-urgent Failure Alarms from Redundant Rod Control Power Supplies.Reactor Manually Tripped.All Four PS-3 Power Supplies replaced.W/950505 Ltr ML17352B1181995-04-0707 April 1995 LER 95-003-00:on 950309,intake Cooling Water Flow Rate Through CCW Heat Exchangers Fell Below Assumed Design Basis. Caused by an Influx of Aquatic Grass & Algae Onto Basket Strainers.Strainers cleaned.W/950407 Ltr ML17352B0701995-03-13013 March 1995 LER 95-002-00:on 950215,inadequate Definition of Loops Filled Resulted in Units in Condition Prohibited by Ts. Issued TS Position Statement to Define Term Loops Filled as Used in TS 6.4.1.1.4.W/950313 Ltr ML17352B0321995-02-0909 February 1995 LER 94-005-01:on 941103,design Defect Found in Safeguards Bus Sequencer Test Logic,Placing Facility Outside Design Basis.Design Mods to Eliminate Software Logic Problems Will Be Implemented During Next Refueling outages.W/950209 Ltr ML17352B0101995-01-20020 January 1995 LER 94-006-00:on 941226,C Main Feedwater Control Valve Failed Closed,Causing Reactor & Turbine Trips.Caused by Loose Screw Terminal Connection.I/P Transducers Replaced W/ New Model W/Different Design Wire connection.W/950120 Ltr ML17352A9511994-12-13013 December 1994 LER 94-006-00:on 941130,Unit 4 Tripped Automatically.Caused by Failure of Flexible Link Connection Between Main Generator B Phase Bus & Associated Isolated Phase Bus Bar. All Bolts on Flexible Link checked.W/941213 Ltr ML17352A8871994-11-10010 November 1994 LER 94-005-00:on 941103,design Defect in Safeguards Bus Sequencer Test Logic Places Both Units Outside Design Basis. Caused by 3A Sequencer Failed to Respond as Expected to Opposite Unit SI signal.W/941110 Ltr ML17352A8851994-11-10010 November 1994 LER 94-004-00:on 941103,Unit 3 Outside Design Basis Due to Two of Three Required Safety Injection Pumps Inoperable. Control Switches for 3A & 3B Safety Injection Pumps Immediately Returned to automatic.W/941110 Ltr ML17352A8421994-10-21021 October 1994 LER 94-004-00:on 940923,Unit 4 Tripped Automatically from Rated Power.Caused by Faulty Regulator Transistor.Faulty Backup Power Supply Replaced & Maint History for Power Supplies reviewed.W/941021 Ltr ML17352A8431994-10-20020 October 1994 LER 94-005-00:on 940924,Unit 4 Manually Tripped.Caused by Manual Actuation.Light Bulb & Socket replaced.W/941020 Ltr ML17352B1671994-08-16016 August 1994 LER 94-003-00:on 940720 & 21,util Discovered That Several Required Valve Stroke Time Surveillances Had Not Been Performed.Caused by Personnel Error.Personnel Reassigned & Procedures and Surveillance Tracking Software Enhanced 1999-07-20
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217L9371999-10-20020 October 1999 Safety Evaluation Supporting Licensee Proposed Alternative from Certain Requirements of ASME Code,Section XI for First 10-Yr Interval Request for Relief for Containment Inservice Insp Program ML17355A4471999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Turkey Point,Units 3 & 4.With 991008 Ltr ML17355A4121999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Turkey Point,Units 3 & 4.With 990909 Ltr ML17355A3981999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Turkey Point,Units 3 & 4.With 990809 Ltr ML17355A3891999-07-20020 July 1999 LER 99-001-00:on 990623,manual Rt from 100% Power Following Multiple Control Rod Drops Was Noted.Caused by Manual Action Taken by Reactor Control Operator.Inspected & Repaired Stationary Gripper Regulating Cards.With 990720 Ltr ML17355A3841999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Turkey Point,Units 3 & 4.With 990713 Ltr ML17355A3681999-06-30030 June 1999 Revised Update to Topical QA Rept, Dtd June 1999 ML17355A3611999-06-30030 June 1999 Refueling Outage ISI Rept. ML17355A3511999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Turkey Point,Units 3 & 4.With 990609 Ltr ML17355A3331999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Turkey Point,Units 3 & 4.With 990511 Ltr ML20217B9871999-04-0808 April 1999 Changes,Tests & Experiments Made as Allowed by 10CFR50.59 for Period Covering 971014-990408 ML17355A2881999-04-0505 April 1999 COLR for Turkey Point Unit 4 Cycle 18. ML17355A2911999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Turkey Point,Units 3 & 4.With 990414 Ltr ML17355A2551999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Turkey Point Nuclear Power Plant,Units 3 & 4.With 990315 Ltr ML17355A2261999-01-31031 January 1999 Monthly Operating Repts for Jan 1999 for Turkey Point,Units 3 & 4.With 990211 Ltr ML17355A2201999-01-20020 January 1999 Refueling Outage ISI Rept. ML17355A1911998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Turkey Point,Units 3 & 4.With 990112 Ltr ML18008A0461998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Turkey Point,Units 3 & 4.With 981209 Ltr ML17354B1921998-11-18018 November 1998 LER 98-007-00:on 981020,containment Purge Supply,Valve Opened Wider than TS Limit.Caused by Improper Setting of Mechanical Stops.Incorporated Improved Standard Method of Measuring Angular Valve Position Into Sp.With 981118 Ltr ML17354B1891998-11-0909 November 1998 Simulatory Certification Update 2. ML17354B1901998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Turkey Point,Units 3 & 4.With 981112 Ltr ML17354B1591998-10-23023 October 1998 COLR for Turkey Point Unit 3 Cycle 17. ML17354B1361998-10-16016 October 1998 LER 98-004-00:on 980921,automatic Reactor Trip Occurred. Caused by Inadequate re-correlation of Intermediate Range Neutron Flux Instrumentation Reactor Trip Bistable. Enhanced Applicable Plant Procedures.With 981016 Ltr ML17354B1311998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for Turkey Point Unit 3 & 4.With 981012 Ltr ML17354B0971998-09-0909 September 1998 Part 21 Rept Re Possible Machining Defect in Certain One Inch Stainless Steel Swagelok Front Ferrules,Part Number SS-1613-1.Caused by Tubing Slipping Out of Fitting at Three Times Working Pressure of Tubing.Notified Affected Utils ML17354B0981998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Turkey Points,Units 3 & 4.With 980915 Ltr ML17354B0771998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Turkey Point,Units 3 & 4.W/980810 Ltr ML17354B0341998-07-15015 July 1998 LER 98-003-00:on 980619,discovered That Auxiliary Feedwater Sys Was Inoperable Due to Inadequate Inservice Testing of Valves.Caused by Misunderstanding of Testing Criteria.Util Revised Procedures & Verified Operability of Valves ML17354B0241998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Turkey Point,Units 3 & 4.W/980709 Ltr ML17354B0171998-06-29029 June 1998 Rev 1 to PTN-FPER-97-013, Evaluation of Turbine Lube Oil Fire. ML17354A9841998-06-18018 June 1998 LER 97-007-01:on 970730,automatic Reactor Trip Occurred Due to Closure of B Msiv.Caused by Failed BFD22S Relay.Six Relays on 3A,3B & 3C MSIVs Were Replaced & Implemented Plant Change to Disable Electronic Trip Function on 3 AFW Pumps ML17354A9741998-06-0909 June 1998 LER 98-002-00:on 980513,discovered Potential LOCA-initiated Electrical Fault Which Places ECCS Outside Design Basis. Caused by Inadequate Review of Effect on non-safety Circuit failures.Re-powered PC-*-600A Relays ML20248F7441998-05-31031 May 1998 Reactor Vessel Working Group,Response to RAI Regarding Reactor Pressure Vessel Integrity ML17354A9711998-05-31031 May 1998 Monthly Operating Repts for Turkey Point,Units 3 & 4. W/980611 Ltr ML17354A9231998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Turkey Point,Units 3 & 4.W/980511 Ltr ML17354A8821998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for Turkey Point,Units 3 & 4.W/980409 Ltr ML17354A8511998-03-24024 March 1998 LER 97-009-01:on 971114,discovered That CR Console Switch for 3B Sgfp Was Not in Start Position.Caused by Inadequate Procedural Guidance.Revised Procedures 3/4-OP-074,informed Personnel of Event & Performed Walkdown of CR ML17354B0001998-03-18018 March 1998 Florida Power & Light Topical Quality Asurance Rept, Dtd June 1998 ML17354A8441998-03-18018 March 1998 LER 98-001-00:on 980216,manual Reactor Trip Occurred Due to Loss of Turbine Control Oil Pressure W/Steam Leak in Auxiliary Feedwater Steam Supply Piping.Auxiliary Governor Maint Instructions Will Be revised.W/980318 Ltr ML17354A8311998-02-28028 February 1998 Monthly Operating Repts for Feb 1998 for Turkey Point,Units 3 & 4.W/980311 Ltr ML17354A7871998-01-31031 January 1998 Monthly Operating Repts for Jan 1998 for Turkey Point,Units 3 & 4.W/980209 Ltr ML17354A7581997-12-31031 December 1997 Monthly Operating Repts for Dec 1997 for Turkey Point,Unit 3 & 4.W/980112 Ltr ML17354A7361997-12-12012 December 1997 LER 97-009-01:on 971114,identified That CR Console Switch for 3B SG Feedwater Pump Was Not in Start Position.Caused by Inadequate Procedural Guidance.Procedures 3/4-OP-074,SGFP Were revised.W/971212 Ltr ML17354A7381997-11-30030 November 1997 Monthly Operating Repts for Nov 1997 for Turkey Point,Units 3 & 4.W/971215 Ltr ML17354A7211997-10-31031 October 1997 Monthly Operating Repts for Oct 1997 for Turkey Point,Units 3 & 4.W/971114 Ltr ML17354A7491997-10-13013 October 1997 SG Insp Rept. ML17354A8851997-10-13013 October 1997 FPL Units 3 & 4 Changes,Tests & Experiments Made as Allowed by 10CFR50.59 for Period Covering 960408-971013. ML17354A6801997-10-0808 October 1997 LER 97-008-00:on 970909,containment Sump Debris Screens Outside Design Basis Due to Stress Damage Was Discovered. Caused by Inadequate Procedural Guidance & Personnel Error. Discrepancies Found on Screens corrected.W/971008 Ltr ML17354A6791997-10-0606 October 1997 COLR Unit 4 Cycle 17, for Turkey Point ML17354A6811997-09-30030 September 1997 Monthly Operating Repts for Sept 1997 for Turkey Point,Units 3 & 4.W/971009 Ltr 1999-09-30
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AO:"ELERATED DISTRIBUTION DEMONSTPWTION SYSTEM REGULAT INFORMATION DISTRIBUTION STEM (RIDS)ACCES.".ZON'NBR:9203180183 DOC.DATE: 92/03/10 NOTARIZED:
NO FACZL:50-250 Turkey Point Plant, Unit 3, Florida Power and Light C AUTH.NAME AUTHOR AFFILIATION MOWREYiC.L.
Florida Power&Light Co.PLUNKETT,T.F.
Florida Power&Light Co.RECIP.NAME RECIPIENT AFFILIATION DOCKET 05000250
SUBJECT:
LER 92-001-00:on 920210 concluded that operability of switchgear w/racked-down braekers could not be asssured.'Caused by incomplete info re seismic qualification of switchgear.Procedures revised.W/920311 ltr.DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE: TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.NOTES:NRR RAGHAVAN,L 05000250 RECIPIENT ID CODE/NAME PD2-2 LA AULUCK,R INTERNAL: ACNW AEOD/DSP/TPAB NRR/DET/EMEB 7E NRR/DLPQ/LPEB10 NRR/DREP/PRPBll NRR/DST/SICB8H3 NRR/DST/SRXB 8E RES/DSIR/EIB EXTERNAL EG&G BRYCEg J~H NRC PDR NSIC POOREiW.NOTES: E COPIES LTTR ENCL 1 1 1 1 2 2 1 1 1 1 1 1 2 2 1 1 1 1 1.1 3 3 1 1 1 1 1 1 RECIPIENT ID CODE/NAME PD2-2 PD AEOD/DOA AEOD/ROAB/DSP NRR/DLPQ/LHFB10 NRR/DOEA/OEAB NRR/DST/SELB 8D NRRQDSQ/-SP:QB8Dl REQ~IiE~0 2@GN2 FILE Ol L ST LOBBY WARD NSIC MURPHYiG.A NUDOCS FULL TXT COPIES LTTR ENCL 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE iVASTE!CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT.20079)TO ELIMINATE YOUR NAiVIE FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!FULL TEXT CONVERSiON R"QUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 31 ENCL 31 AARcB ll 1992 L-92-070 10 CFR 50.73 U.S.Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C.20555 Gentlemen:
Re: Turkey Point Unit 3 Docket No.50-250 Reportable Event: 92-001-00 Operation With 4160 Volt Switchgear In A Configuration For Which Seismic uglification Was Not Evaluated The attached Licensee Event Report 250-92-001-00
'is being provided in accordance with 10 CFR 50.73 (a)(2)(ii)to provide notification of the subject condition.
Very truly yours, T.F~Plunkett Vice President Turkey Point Nuclear TFP/CLM/cm attachment cc: Stewart D.Ebneter, Regional Administrator, Region II, USNRC Ross C.Butcher, Senior Resident Inspector, USNRC, Turkey Point Plant 92031801S3
'7203l0 PDR ADOCK 0"-000250 PDR FACILITY NAME (1)LICENSEE EVENT REPORT (LER)DOCKET NUMBER (2)PACE (3)TITLE (4)TURKEY POINT UNITS 3 and 4 05000250 oF 4 Operation With 4160 Volt Circuit Breakers in a Configuration for Which Seismic Qualification was not Evaluated EVENT DATE (5)LER NUMBER(6)RPT DATE ('))OTHER FACILITIES INV.(8)MON YR YR SEO 0 R(MON DAY FACILITY NAMES DOCKET J (S)06 22 92 001 00 03 10 92 TURKEY POINT UNIT 4 05000251 OPERATING MODE (9)POHER LEVEI (10)100/100 10 CFR 50.73 a 2 ii LICENSEE CONTACT FOR THIS LER (12)Craig L.Mowrey, Licensing Engineer TELEPHONE NUMBER 305-246-6204 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)CAUSE SYSTEM COMPONENT MANUFACTURER NPRDS2 CAUSE SYSTEM COMPONENT MANUFACTURER NPRDST SUPPLEMENTAL REPORT EXPECTED (14)NO Rl YES 0 (If yes, cccylete EXPECTED SUBMISSION DATE)EXPECTED SUBMISSION DATE (15)MONTH DAY YEAR ABSTRACT (16)Since 1984, Turkey Point has routinely placed certain 4160 volt safety-related breakers in a racked-down configuration.
The seismic qualification for the switchgear had been based on all breakers being racked up.In October, 1991, Turkey Point placed wooden chocks against the wheels of all normally racked-down safety-related breakers, to ensure that the seismic qualification of the switchgear was not adversely affected, and began investigating the need for the chocks and the operability of the switchgear.
On February 10, 1992, FPL concluded that operability of the switchgear with racked-down breakers (prior to installation of the chocks)could not be assured, and declared the as-found condition to be inoperable and therefore reportable.
Seismic qualification of the switchgear with racked-down breakers does not appear to have been considered in earlier design evaluations.
The low seismicity of South Florida, the low probability of any seismic event, and the low probability that such an event could render both vital buses inoperable, combine to minimize the potential safety significance of the as-found condition.
Procedures were revised to require chocks and chocks were installed, in October, 1991.A Design Basis Document change will be initiated to clarify the seismic qualification limitations for the switchgear.
LZCENSEE~REPORT (LER)TEXT COL'ZNUATZON FACILITY NAME DOCKET NUMBER LER NUMBER PAGE NO.TURKEY POINT UNIT 3 05000250 92-001-00 02 OF 04 EVENT DESCRIPTION In June, 1991, Florida Power and Light Company (FPL)discovered via the Institute of Nuclear Power Operations that Arkansas Nuclear One had determined that their General Electric 4160 Volt Engineered Safety Features Switchgear
[EIIS:EB]was being operated in a configuration which had not been seismically qualified.
Four circuit breakers[EIIS:EB;COMPONENT:52]
were routinely positioned in a racked-down configuration, while the seismic qualification calculations were based on all breakers being racked up.In October, 1991, FPL determined that similar unanalyzed switchgear configurations existed at Turkey Point, i.e., racked-out breakers were physically racked down.FPL committed to keep certain bus tie breakers racked down in a 1984 letter to the USNRC.Although the switchgear could not be qualified with any certainty in this configuration, FPL determined that wooden chocks placed against the wheels of the racked-down breakers would provide positive assurance that (1)there would be no adverse interaction between the racked-down breakers and any safety related equipment, (2)there would be no adverse effects on the safety-related function of the switchgear and (3)the seismic qualification of the switchgear would not be adversely affected.FPL also determined that the relays mounted on the front door of the cabinet are installed on the upper end of the door and cannot be directly impacted by the breaker if it were to hit the door.Wooden chocks were installed against the wheels of all racked-down breakers on October 18, 1991.In November, 1991, in separate correspondence, FPL completed an investigation of the affected switchgear.
This included a review of Turkey Point documents as well as a survey of other utilities that had been questioned by the USNRC on this issue during Select System inspections.
The purpose of these reviews was to determine if the original unblocked configuration of the breakers would be acceptable, and the wooden chocks could be eliminated.
FPL determined that it could not be concluded that the unrestrained breakers on rollers would not adversely affect the switchgear cabinet relays, and therefore chocking of the racked-down breakers should continue.On February 10, 1992, FPL concluded that operability of the switchgear with racked-down breakers (prior to installation of the chocks)could not be assured.On that basis the as-found condition was considered to be reportable in accordance with10 CFR 50.73(a)(2)(ii)(B).The NRC Operations Center was notified of the reportable condition at 0911, February 10, 1992.
I LICENSEE ANT REPORT (LER)TEXT SINUATION FACILITY NAME DOCKET NtjMBER TURKEY POINT UNIT 3 05000250'ER NUMBER PAGE NO.92-001-00 03 OF 04 The commitment to maintain the bus tie breakers racked down was made in FPL letter to NRC L-84-157, which transmitted Turkey Point's Auxiliary Power Upgrade Summa'ry and Design Evaluation.
This configuration commitment was made to supplement the protection against interaction between the non-safety related C Bus[EIIS:EA], and the nuclear safety related buses.The as-found condition is considered to have existed since the issuance of L-84-157 on June 22, 1984, and is indeterminate prior to that date.During the engineering evaluation, Asea Brown Boveri (ABB)switchgear breakers were also discovered in the unrestrained racked-out (maintenance) positions The ABB circuit breakers[EIIS:EB;COMPONENT:52]
were procedurally allowed to be positioned in a maintenance configuration, while the seismic qualification calculations were based on all breakers being racked-in (restrained).
The ABB switchgear breakers are racked-out horizontally involving no change in height of the center of gravity and will not adversely affect the qualification of the switchgear.
The evaluation required a procedure change to ensure the breakers were restrained.
II.EVENT CAUSE Seismic qualification of the circuit breakers in the racked-down position was not discussed in the design evaluation transmitted in L-84-157.Limitation of seismic qualification to the racked-up configuration was also not addressed in the licensing basis documents.
The root cause of this event is incomplete information concerning seismic qualification of the 4160 volt switchgear, with racked-down breakers, in the licensing basis documents.
III.EVENT SAFETY ANALYSIS Four factors mitigate the potential consequences of the breakers in the racked-down position: (1)moving the breakers to the racked-down position reduces the amount of mass being carried by the vertical support members of the cabinet, and lowers the center of gravity of the switchgear; (2)the design seismic loadings used during equipment qualification are well in excess of the response accelerations associated with electrical equipment at Turkey Point;(3)lowering the breaker increases the natural frequency of the critical component in the switchgear (the jackscrew);
and (4)the freedom of movement of the breakers is limited to approximately one inch front-to-back, while guide angles on the floor restrain any side to side movement.
LICENSEE lNT REPORT (LER)TEXT C'INCATION FACILITY NAME TURKEY POINT UNIT 3 DOCKET NUMBER 05000250 LER NUMBER PAGE NO.92-001-00 04 OF 04 The primary safety considerations for seismic events are the capability to conduct a safe plant shutdown and maintain the plant in a safe shutdown condition.
The potential for'ndirect damage to the relays in the vital buses indicates that impairment of this capability could be postulated if a seismic event of sufficient magnitude were to have occurred with the circuit breakers in an unqualified configuration.
The specific damage that may have resulted from a seismic event cannot be determined.
The low seismicity of South Florida, the low probability of any seismic event, and the extremely low probability that both 4160 volt vital buses would be rendered inoperable as a result of seismic interaction, combine to minimize the potential safety significance of this condition..Both buses would have to be inoperable to impair the ability to shut down safely because of redundant equipment powered from either bus.Therefore, the health and safety of the public was not significantly impacted by the as-found condition.
IV.CORRECTIVE ACTIONS Procedures 3-OP-005 and 4-OP-005 were revised with On The Spot Changes (OTSC)on October 18, 1991, to include a precaution to chock the front wheels of GE 4160 volt breakers when racked down or in the test position.The OTSCs were reviewed and approved by the Plant Nuclear Safety Committee on October 22, 1991.2.Chocks were installed against the front wheels of the GE 4160 volt, racked-down tie breakers on October 18, 1991.ABB breakers were required to be maintained in the racked-out (restrained) position as opposed to maintenance (unrestrained) position when not racked-in.
3.A change to the Design Basis Document will be initiated to discuss the seismic qualification of the 4160 volt nuclear safety related breakers in the racked-down position.This change will be completed during the next scheduled update to the Design Basis Document in 1993.V.ADDITIONAL INFORMATION The circuit breakers are MAGNA-BLAST type AM-4.16-350-1H or AM-4.16-350-2H, manufactured by General Electric or ABB Type 5 HK-250-1200A manufactured by Asea Brown Boveri.Since other plants may have different configurations (more freedom of movement, relays mounted lower, more severe design basis seismic events), this Licensee Event Report provides an alternative solution to that given in LER 368-91-014.
Energy Industry Identification System (EIIS)codes are identified in the text as[EIIS:XX].
When a component code is included, the form is[EIIS:XX;COMPONENT:xxj.
No similar events involving seismic qualification have been reported for Turkey Point~