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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML17313B0751999-08-27027 August 1999 LER 99-002-00:on 990730,test Mode Trip Bypass for EDG Output Breakers Not Surveilled.Cause Under Investigation.Operations Personnel Conservatively Invoked SR 3.0.3 for SR 3.8.1.13. with 990827 Ltr ML17313B0191999-07-16016 July 1999 LER 99-005-00:on 990618,RT on Low DNBR Was Noted.Caused by Hardware Induced Calculation Error.Cr Operator Was Taken to Place Reactor in Stable Condition IAW Appropriate Operating Procedure ML17313A9281999-05-0707 May 1999 LER 99-004-00:on 990408,PSV Lift Pressures Were Outside of TS Limits.Caused by Lift Pressure Setpoint Drift.Psvs Have Been Tested,Disassembled,Inspected,Reassembled & Certified at Wyle Labs ML17313A8951999-04-14014 April 1999 LER 99-003-00:on 990317,required Surveillance Requirement Not Completed Due to Deficient Procedure,Was Determined. Caused by Cognitive Personnel Error.St Procedures Revised to Require Chiller to Be Operating & Oil Temperature Checked ML17313A8921999-04-13013 April 1999 LER 98-003-01:on 980902,discovered That MSSV as-found Lift Pressures Were Outside TS Limits.Caused by Bonding of Valve Disc to Nozzle Seat.Affected Valves Were Adjusted,Retested & Returned to Svc ML17313A8891999-04-0909 April 1999 LER 99-001-00:on 990310,RT on High Pressurizer Pressure Was Noted.Caused by Loss of Heat Removal.Cr Supervisor Was Removed from Shift Duties for Diagnostics Skills Training. with 990409 Ltr ML17313A8361999-03-0101 March 1999 LER 99-001-00:on 990103,TS Violation for Power Dependent Insertion Limit Alarm Being Inoperable.Caused by Personnel Error.Revised Procedure to Clarify How Computer Point Is to Be Returned to Scan Mode.With 990302 Ltr ML17313A7701999-01-15015 January 1999 LER 96-008-00:on 960507,inadequate Procedure Results in Nuclear Power Channels Not Calibrated During Power Ascension Tests Occurred.Caused by Deficient Procedure.Procedure Revised ML17313A6611998-10-24024 October 1998 LER 98-008-00:on 980729,EQ of Electrical Connectors Were Not Adequately Demonstrated.Caused Because Test Was Conducted with Only Single Lv Connector & Without Fully Ranged Inputs. Revised EQ Requirements ML17313A5961998-09-14014 September 1998 LER 98-002-00:on 980814,B Train H Recombiner Was Noted Inoperable Due to cross-wired Power Receptacle.Cause of Event Is Under investigation.Cross-wired Power Supply Receptacle for B Train H Recombiner Was re-wired ML17313A5761998-09-0808 September 1998 LER 98-003-01:on 980113,discovered That One Channel of RWT Level Sys Had Failed High.Caused by Water Intrusion Into Electrical Termination Pull Box.Weep Holes Were Drilled Into Bottoms of Pull Boxes Nearest Level Transmitters ML17313A5591998-08-28028 August 1998 LER 98-001-00:on 980730,entered TS 3.0.3 Due to Safety Injection Flow Instruments Being Removed from Svc.Caused by Personnel Error.Transmitters Were Unisolated & Returned to svc.W/980828 Ltr ML17313A5201998-07-30030 July 1998 LER 98-004-00:on 980630,personnel Discovered That Pressure Safety Valve Had Not Received Periodic Set Pressure Test for ASME Class 1 Pressure Safety Valve.Caused by Personnel Error.Pressure Safety Valve reviewed.W/980730 Ltr ML17313A4671998-06-19019 June 1998 LER 98-007-00:on 980520,CR Personnel Observed Flow & Pressure Perturbations on Chemical & Vol Control Sys Letdown Sys.Caused by Cyclic Fatigue Due to Dynamic Pressure Transients.Unit Letdown Piping Replaced ML17313A4131998-06-0505 June 1998 LER 98-006-00:on 980507,determined That Plant Was Outside Design Basis Due to SI Discharge Check Valve Reverse Flow. Check Valve Was Disassembled,Examined & Reassembled, Whereupon Valve Met Acceptance Criteria ML17313A3951998-05-26026 May 1998 LER 98-005-00:on 980428,noted That Required Response Time Testing Had Not Been Performed.Caused by Personnel Error. Coached I&C Personnel Responsible for Reviewing Work Authorization Documentation ML17313A3251998-04-0101 April 1998 LER 98-004-00:on 980304,safety Valves as-found Pressures Out of Tolerance.Cause of Event Is Under Investigation.Three Mssv'S & Psv Will Be Replaced W/Refurbished & Recertified Valves During Refueling Outage U1R7 ML17313A3131998-03-21021 March 1998 LER 98-001-00:on 980301,surveillance Test Deficiency Found During Qaa Leads to TS 3.0.3/4.0.3 Entry.Caused by Personnel Error.Personnel Responsible for Inadequately Performed SR Were Coached ML17313A2251998-03-0505 March 1998 LER 93-005-00:on 930309,CR Personnel Discovered Missed TS LCO Action & Subsequently Performed Surveillance Satisfactorily.Caused by Personnel Error.Appropriate Disciplinary Action issued.W/980305 Ltr ML17313A2241998-02-26026 February 1998 LER 98-001-00:on 980130,reactor Protection & ESFAS Instrumentation Not Bypassed within one-hour Allowed by TS Occurred.Caused by Inadequate Procedures.Expectation to Detect Alarm Conditions Was Emphasized to CR Personnel ML17313A2081998-02-10010 February 1998 LER 97-007-00:on 971006,TS Violation Occurred Due to Inadequate Shutdown Cooling Flow During Modes 5 & 6 Operation.Independent Investigation of Event Was Conducted IAW APS CA program.W/980210 Ltr ML17313A2041998-02-0505 February 1998 LER 97-006-00:on 971028,missed TS 4.0.5 SR Was Noted.Caused by Personnel Error.Independent Investigation of Event Is Being Conducted IAW W/Aps Corrective Action Program ML17313A1201997-11-12012 November 1997 LER 97-006-00:on 971020,manual Reactor Trip Occurred Due to Vibration & Bearing Temp Increases in Reactor Coolant Pump. Caused by Failed Lower Journal Bearing.Bearing Assembly Was Disassembled,Inspected & Rebuilt ML17312B7181997-10-0707 October 1997 LER 97-003-00:on 970907,inadvertent Loss of Power & EDG Start Occurred Due to Procedural Error.Changed Train a & Train B Edg/Ist ST Procedures to Consistently Reflect Proper Pretest Staging Hand switches.W/971007 Ltr ML17312B7051997-09-26026 September 1997 LER 97-003-01:on 970215,seven Main Steam Safety Valves Were Found Out of Tolerance Prior to Refueling Outage.Safety Analysis Performed Based Upon as-found MSSV Data Which Demonstrated That MSSVs Would Perform Safety Functions ML17312B5531997-07-0707 July 1997 LER 97-002-00:on 970528,SR for Core Protection Was Not Performed Due to Inadequate Procedures.Revised Procedures ML17312B5501997-07-0707 July 1997 LER 97-003-00:on 970211,notified of Trevitest Activities Indicating That Total of Seven MSSVs Had as-found Lift Set Pressures Greater than 3 Percent Allowed by TS 3.7.1.1. Investigation Conducted.Seven MSSVs replaced.W/970707 Ltr ML17312B4971997-06-13013 June 1997 LER 97-002-00:on 970531,RT Occurred.Caused by Spurious Opening of All Four Rt Switchgear Breakers.Independent Investigation of Event Being Conducted in Accordance W/Util Corrective Action Program ML17312B1461996-12-17017 December 1996 LER 96-007-00:on 961119,surveillance Test Deficiencies Were Found During GL 96-01 Review Leading to TS 3.0.3 Entries. Caused by Increase in Scope of Required Testing.Supplement Will Be submitted.W/961217 Ltr ML17312A9511996-09-0404 September 1996 LER 96-003-00:on 960809,open Auxiliary Bldg Door Caused Full Bldg Essential Filtration Inoperability.Caused by Personnel Error.C/As Under consideration.W/960904 Ltr ML17312A8641996-07-17017 July 1996 LER 96-001-00:on 960621,inaccurate Gas Calculations for Post Accident Sampling Sys Occurred.Caused by Surveillance Test Worksheet Errors.Independent Investigation of Event Being conducted.W/960717 Ltr ML17300B2541996-06-11011 June 1996 LER 96-001-01:on 960404,inappropriate Grounding of Equipment Resulted in Condition Outside Design Basis of Plant. Established Fire Watches Required for Affected Areas ML17312A8081996-06-0909 June 1996 LER 96-002-00:on 960514,Tech Spec Violation Occurred Due to Erroneous Surveillance Requirement.Caused by Incorporation of C-E Generic Ts.Investigation Being conducted.W/960609 Ltr ML17312A7751996-05-17017 May 1996 LER 96-003-00:on 960122,missed Surveillance for Logic Check of Logs 1 & 2 Safety Excore Bypasses.Caused by Procedural Error.Log Power Functional Test Revised to Check Logs 1 & 2 Bypasses Regardless of Power level.W/960517 Ltr ML17312A7511996-05-0606 May 1996 LER 96-001-00:on 960404,smoke Discovered in Back Boards Area of CR by Security Officer,Performing Hourly Fire Watch Tour. Caused by Improperly Grounded Circuit.Investigation for Inappropriate Grounding of Low Voltage Power Sys Initiated ML17312A7241996-04-25025 April 1996 LER 96-002-00:on 960401,inappropriate Work Practice Resulted in Esfa of Train B Edg.Night Order Was Issued to All Three Units Describing event.W/960425 Ltr ML17312A6861996-04-0606 April 1996 LER 95-007-01:on 950512,determined That Bench Settings of air-operated Letdown & Containment Isolation Valves Adversely Affected Ability of Valves to Perform 10CFR50 App R Safety Function.Affected Valves Modified ML17312A5631996-02-22022 February 1996 LER 95-016-00:on 951212,containment Spray TS Violation Occurred Due to Unrecognized Valve Failure.Shim/Band Was Placed Around Stator of 1JSIBUV665 Motor Operator to Maintain Stator in Correct position.W/960222 Ltr ML17311B3381996-01-0909 January 1996 LER 95-014-00:on 951209,reactor Tripped Following Degradation of Main FW Flow.Caused by Malfunction of Fwcs Power supply,NNN-D11,transfer switch.NNN-D11 Aligned to Normal Power supply.W/960109 Ltr ML17311B3331995-12-31031 December 1995 LER 95-013-00:on 951201,AFW Sys Was Outside Design Basis of Plant.Caused by Design Error.Performed Assessment to Demonstrate That Existing Condition Does Not Pose Addl Safety concerns.W/951231 Ltr ML17311B2801995-11-23023 November 1995 LER 95-011-00:on 951018,identified Procedural Deficiency W/Msiv & FWIV ISTs Due to Personnel Error.Verified Operability of MSIVs & FWIVs.W/951123 Ltr ML17311B2531995-10-20020 October 1995 LER 95-002-00:on 950924,identified That Abnormal Blowdown Valves to Blowdown Flash Tank (Bft) Isolated,Resulting in Reactor Core Power Exceeding 3,800 Mwt Due to Personnel Error.Procedure for Aligning Blowdown to Bft Revised ML17311B1991995-09-21021 September 1995 LER 95-010-00:on 950727,equipment Qualification of Air Handling Unit Caused Essential Cw Pump to Be Inoperable. Used Work Orders to Drill Weep Holes in Motor Lead Connection boxes.W/950921 Ltr ML17311B1741995-09-0404 September 1995 LER 95-004-01:on 950329,containment Electrical Penetration Overcurrent Protective Devices Found Outside Design Basis. Caused by Error on Part of Original Architect Engineer. Modified Affected Circuits Critical to Normal Operational ML17311B1561995-08-27027 August 1995 LER 95-003-00:on 950729,switchyard Voltage Dropped Below Administratively Imposed Limit of 524 Kv for Approx 10 Seconds Due to Transient Grid Voltage.No C/A Taken Since Transmission Sys Transient Short duration.W/950827 Ltr ML17311B1551995-08-25025 August 1995 LER 95-002-01:on 950303,identified That Slb Analyses Failed to Consider as Initial Condition One Percent SDM for All Rods in (ARI) Due to Lack of Coordination & Unclear Div of Responsibilities.Ari Core Data Book SDM Curves Modified ML17311B1211995-08-16016 August 1995 LER 95-005-00:on 950717,RT on Low SG Water Level Was Result Following Degradation of MFW Flow.Completed Evaluation of Event ML17311B0841995-07-28028 July 1995 LER 94-005-01:on 941019,completed TS Required Shutdown Due to Expiration of LCO Time Limit.Design Change Options Identified & Will Be Reviewed to Determine If Valve &/Or Motor Operator Replacement or Mod Necessary ML17311B0721995-07-20020 July 1995 LER 95-004-00:on 950706,identified Four Occassions Between 950407 & 0630 When Conditional Surveillance in TS LCO 3.8.4.1 Action a Not Performed Due to Inattention to Detail. CR Copy of Temporary Procedure 40TP-9ZZ04 Corrected ML17311B0081995-07-0606 July 1995 LER 95-003-00:on 950613,TS LCO 3.0.3 Entered Following Loss of Both Trains of Essential Cw Sys & Both Hydrogen Recombiners.Caused by Spurious Actuations Due to Broken EDG Speed Probe Connector.Connector replaced.W/950706 Ltr 1999-08-27
[Table view] Category:RO)
MONTHYEARML17313B0751999-08-27027 August 1999 LER 99-002-00:on 990730,test Mode Trip Bypass for EDG Output Breakers Not Surveilled.Cause Under Investigation.Operations Personnel Conservatively Invoked SR 3.0.3 for SR 3.8.1.13. with 990827 Ltr ML17313B0191999-07-16016 July 1999 LER 99-005-00:on 990618,RT on Low DNBR Was Noted.Caused by Hardware Induced Calculation Error.Cr Operator Was Taken to Place Reactor in Stable Condition IAW Appropriate Operating Procedure ML17313A9281999-05-0707 May 1999 LER 99-004-00:on 990408,PSV Lift Pressures Were Outside of TS Limits.Caused by Lift Pressure Setpoint Drift.Psvs Have Been Tested,Disassembled,Inspected,Reassembled & Certified at Wyle Labs ML17313A8951999-04-14014 April 1999 LER 99-003-00:on 990317,required Surveillance Requirement Not Completed Due to Deficient Procedure,Was Determined. Caused by Cognitive Personnel Error.St Procedures Revised to Require Chiller to Be Operating & Oil Temperature Checked ML17313A8921999-04-13013 April 1999 LER 98-003-01:on 980902,discovered That MSSV as-found Lift Pressures Were Outside TS Limits.Caused by Bonding of Valve Disc to Nozzle Seat.Affected Valves Were Adjusted,Retested & Returned to Svc ML17313A8891999-04-0909 April 1999 LER 99-001-00:on 990310,RT on High Pressurizer Pressure Was Noted.Caused by Loss of Heat Removal.Cr Supervisor Was Removed from Shift Duties for Diagnostics Skills Training. with 990409 Ltr ML17313A8361999-03-0101 March 1999 LER 99-001-00:on 990103,TS Violation for Power Dependent Insertion Limit Alarm Being Inoperable.Caused by Personnel Error.Revised Procedure to Clarify How Computer Point Is to Be Returned to Scan Mode.With 990302 Ltr ML17313A7701999-01-15015 January 1999 LER 96-008-00:on 960507,inadequate Procedure Results in Nuclear Power Channels Not Calibrated During Power Ascension Tests Occurred.Caused by Deficient Procedure.Procedure Revised ML17313A6611998-10-24024 October 1998 LER 98-008-00:on 980729,EQ of Electrical Connectors Were Not Adequately Demonstrated.Caused Because Test Was Conducted with Only Single Lv Connector & Without Fully Ranged Inputs. Revised EQ Requirements ML17313A5961998-09-14014 September 1998 LER 98-002-00:on 980814,B Train H Recombiner Was Noted Inoperable Due to cross-wired Power Receptacle.Cause of Event Is Under investigation.Cross-wired Power Supply Receptacle for B Train H Recombiner Was re-wired ML17313A5761998-09-0808 September 1998 LER 98-003-01:on 980113,discovered That One Channel of RWT Level Sys Had Failed High.Caused by Water Intrusion Into Electrical Termination Pull Box.Weep Holes Were Drilled Into Bottoms of Pull Boxes Nearest Level Transmitters ML17313A5591998-08-28028 August 1998 LER 98-001-00:on 980730,entered TS 3.0.3 Due to Safety Injection Flow Instruments Being Removed from Svc.Caused by Personnel Error.Transmitters Were Unisolated & Returned to svc.W/980828 Ltr ML17313A5201998-07-30030 July 1998 LER 98-004-00:on 980630,personnel Discovered That Pressure Safety Valve Had Not Received Periodic Set Pressure Test for ASME Class 1 Pressure Safety Valve.Caused by Personnel Error.Pressure Safety Valve reviewed.W/980730 Ltr ML17313A4671998-06-19019 June 1998 LER 98-007-00:on 980520,CR Personnel Observed Flow & Pressure Perturbations on Chemical & Vol Control Sys Letdown Sys.Caused by Cyclic Fatigue Due to Dynamic Pressure Transients.Unit Letdown Piping Replaced ML17313A4131998-06-0505 June 1998 LER 98-006-00:on 980507,determined That Plant Was Outside Design Basis Due to SI Discharge Check Valve Reverse Flow. Check Valve Was Disassembled,Examined & Reassembled, Whereupon Valve Met Acceptance Criteria ML17313A3951998-05-26026 May 1998 LER 98-005-00:on 980428,noted That Required Response Time Testing Had Not Been Performed.Caused by Personnel Error. Coached I&C Personnel Responsible for Reviewing Work Authorization Documentation ML17313A3251998-04-0101 April 1998 LER 98-004-00:on 980304,safety Valves as-found Pressures Out of Tolerance.Cause of Event Is Under Investigation.Three Mssv'S & Psv Will Be Replaced W/Refurbished & Recertified Valves During Refueling Outage U1R7 ML17313A3131998-03-21021 March 1998 LER 98-001-00:on 980301,surveillance Test Deficiency Found During Qaa Leads to TS 3.0.3/4.0.3 Entry.Caused by Personnel Error.Personnel Responsible for Inadequately Performed SR Were Coached ML17313A2251998-03-0505 March 1998 LER 93-005-00:on 930309,CR Personnel Discovered Missed TS LCO Action & Subsequently Performed Surveillance Satisfactorily.Caused by Personnel Error.Appropriate Disciplinary Action issued.W/980305 Ltr ML17313A2241998-02-26026 February 1998 LER 98-001-00:on 980130,reactor Protection & ESFAS Instrumentation Not Bypassed within one-hour Allowed by TS Occurred.Caused by Inadequate Procedures.Expectation to Detect Alarm Conditions Was Emphasized to CR Personnel ML17313A2081998-02-10010 February 1998 LER 97-007-00:on 971006,TS Violation Occurred Due to Inadequate Shutdown Cooling Flow During Modes 5 & 6 Operation.Independent Investigation of Event Was Conducted IAW APS CA program.W/980210 Ltr ML17313A2041998-02-0505 February 1998 LER 97-006-00:on 971028,missed TS 4.0.5 SR Was Noted.Caused by Personnel Error.Independent Investigation of Event Is Being Conducted IAW W/Aps Corrective Action Program ML17313A1201997-11-12012 November 1997 LER 97-006-00:on 971020,manual Reactor Trip Occurred Due to Vibration & Bearing Temp Increases in Reactor Coolant Pump. Caused by Failed Lower Journal Bearing.Bearing Assembly Was Disassembled,Inspected & Rebuilt ML17312B7181997-10-0707 October 1997 LER 97-003-00:on 970907,inadvertent Loss of Power & EDG Start Occurred Due to Procedural Error.Changed Train a & Train B Edg/Ist ST Procedures to Consistently Reflect Proper Pretest Staging Hand switches.W/971007 Ltr ML17312B7051997-09-26026 September 1997 LER 97-003-01:on 970215,seven Main Steam Safety Valves Were Found Out of Tolerance Prior to Refueling Outage.Safety Analysis Performed Based Upon as-found MSSV Data Which Demonstrated That MSSVs Would Perform Safety Functions ML17312B5531997-07-0707 July 1997 LER 97-002-00:on 970528,SR for Core Protection Was Not Performed Due to Inadequate Procedures.Revised Procedures ML17312B5501997-07-0707 July 1997 LER 97-003-00:on 970211,notified of Trevitest Activities Indicating That Total of Seven MSSVs Had as-found Lift Set Pressures Greater than 3 Percent Allowed by TS 3.7.1.1. Investigation Conducted.Seven MSSVs replaced.W/970707 Ltr ML17312B4971997-06-13013 June 1997 LER 97-002-00:on 970531,RT Occurred.Caused by Spurious Opening of All Four Rt Switchgear Breakers.Independent Investigation of Event Being Conducted in Accordance W/Util Corrective Action Program ML17312B1461996-12-17017 December 1996 LER 96-007-00:on 961119,surveillance Test Deficiencies Were Found During GL 96-01 Review Leading to TS 3.0.3 Entries. Caused by Increase in Scope of Required Testing.Supplement Will Be submitted.W/961217 Ltr ML17312A9511996-09-0404 September 1996 LER 96-003-00:on 960809,open Auxiliary Bldg Door Caused Full Bldg Essential Filtration Inoperability.Caused by Personnel Error.C/As Under consideration.W/960904 Ltr ML17312A8641996-07-17017 July 1996 LER 96-001-00:on 960621,inaccurate Gas Calculations for Post Accident Sampling Sys Occurred.Caused by Surveillance Test Worksheet Errors.Independent Investigation of Event Being conducted.W/960717 Ltr ML17300B2541996-06-11011 June 1996 LER 96-001-01:on 960404,inappropriate Grounding of Equipment Resulted in Condition Outside Design Basis of Plant. Established Fire Watches Required for Affected Areas ML17312A8081996-06-0909 June 1996 LER 96-002-00:on 960514,Tech Spec Violation Occurred Due to Erroneous Surveillance Requirement.Caused by Incorporation of C-E Generic Ts.Investigation Being conducted.W/960609 Ltr ML17312A7751996-05-17017 May 1996 LER 96-003-00:on 960122,missed Surveillance for Logic Check of Logs 1 & 2 Safety Excore Bypasses.Caused by Procedural Error.Log Power Functional Test Revised to Check Logs 1 & 2 Bypasses Regardless of Power level.W/960517 Ltr ML17312A7511996-05-0606 May 1996 LER 96-001-00:on 960404,smoke Discovered in Back Boards Area of CR by Security Officer,Performing Hourly Fire Watch Tour. Caused by Improperly Grounded Circuit.Investigation for Inappropriate Grounding of Low Voltage Power Sys Initiated ML17312A7241996-04-25025 April 1996 LER 96-002-00:on 960401,inappropriate Work Practice Resulted in Esfa of Train B Edg.Night Order Was Issued to All Three Units Describing event.W/960425 Ltr ML17312A6861996-04-0606 April 1996 LER 95-007-01:on 950512,determined That Bench Settings of air-operated Letdown & Containment Isolation Valves Adversely Affected Ability of Valves to Perform 10CFR50 App R Safety Function.Affected Valves Modified ML17312A5631996-02-22022 February 1996 LER 95-016-00:on 951212,containment Spray TS Violation Occurred Due to Unrecognized Valve Failure.Shim/Band Was Placed Around Stator of 1JSIBUV665 Motor Operator to Maintain Stator in Correct position.W/960222 Ltr ML17311B3381996-01-0909 January 1996 LER 95-014-00:on 951209,reactor Tripped Following Degradation of Main FW Flow.Caused by Malfunction of Fwcs Power supply,NNN-D11,transfer switch.NNN-D11 Aligned to Normal Power supply.W/960109 Ltr ML17311B3331995-12-31031 December 1995 LER 95-013-00:on 951201,AFW Sys Was Outside Design Basis of Plant.Caused by Design Error.Performed Assessment to Demonstrate That Existing Condition Does Not Pose Addl Safety concerns.W/951231 Ltr ML17311B2801995-11-23023 November 1995 LER 95-011-00:on 951018,identified Procedural Deficiency W/Msiv & FWIV ISTs Due to Personnel Error.Verified Operability of MSIVs & FWIVs.W/951123 Ltr ML17311B2531995-10-20020 October 1995 LER 95-002-00:on 950924,identified That Abnormal Blowdown Valves to Blowdown Flash Tank (Bft) Isolated,Resulting in Reactor Core Power Exceeding 3,800 Mwt Due to Personnel Error.Procedure for Aligning Blowdown to Bft Revised ML17311B1991995-09-21021 September 1995 LER 95-010-00:on 950727,equipment Qualification of Air Handling Unit Caused Essential Cw Pump to Be Inoperable. Used Work Orders to Drill Weep Holes in Motor Lead Connection boxes.W/950921 Ltr ML17311B1741995-09-0404 September 1995 LER 95-004-01:on 950329,containment Electrical Penetration Overcurrent Protective Devices Found Outside Design Basis. Caused by Error on Part of Original Architect Engineer. Modified Affected Circuits Critical to Normal Operational ML17311B1561995-08-27027 August 1995 LER 95-003-00:on 950729,switchyard Voltage Dropped Below Administratively Imposed Limit of 524 Kv for Approx 10 Seconds Due to Transient Grid Voltage.No C/A Taken Since Transmission Sys Transient Short duration.W/950827 Ltr ML17311B1551995-08-25025 August 1995 LER 95-002-01:on 950303,identified That Slb Analyses Failed to Consider as Initial Condition One Percent SDM for All Rods in (ARI) Due to Lack of Coordination & Unclear Div of Responsibilities.Ari Core Data Book SDM Curves Modified ML17311B1211995-08-16016 August 1995 LER 95-005-00:on 950717,RT on Low SG Water Level Was Result Following Degradation of MFW Flow.Completed Evaluation of Event ML17311B0841995-07-28028 July 1995 LER 94-005-01:on 941019,completed TS Required Shutdown Due to Expiration of LCO Time Limit.Design Change Options Identified & Will Be Reviewed to Determine If Valve &/Or Motor Operator Replacement or Mod Necessary ML17311B0721995-07-20020 July 1995 LER 95-004-00:on 950706,identified Four Occassions Between 950407 & 0630 When Conditional Surveillance in TS LCO 3.8.4.1 Action a Not Performed Due to Inattention to Detail. CR Copy of Temporary Procedure 40TP-9ZZ04 Corrected ML17311B0081995-07-0606 July 1995 LER 95-003-00:on 950613,TS LCO 3.0.3 Entered Following Loss of Both Trains of Essential Cw Sys & Both Hydrogen Recombiners.Caused by Spurious Actuations Due to Broken EDG Speed Probe Connector.Connector replaced.W/950706 Ltr 1999-08-27
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML17300B3811999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Pvngs,Units 1,2 & 3.With 991007 Ltr ML17300B3271999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Pvngs,Units 1,2 & 3 ML17313B0751999-08-27027 August 1999 LER 99-002-00:on 990730,test Mode Trip Bypass for EDG Output Breakers Not Surveilled.Cause Under Investigation.Operations Personnel Conservatively Invoked SR 3.0.3 for SR 3.8.1.13. with 990827 Ltr ML17313B0611999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Pvngs,Units 1,2 & 3.With 990810 Ltr ML17313B0191999-07-16016 July 1999 LER 99-005-00:on 990618,RT on Low DNBR Was Noted.Caused by Hardware Induced Calculation Error.Cr Operator Was Taken to Place Reactor in Stable Condition IAW Appropriate Operating Procedure ML17300B3151999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Pvngs,Units 1,2 & 3.With 990714 Ltr ML17313A9921999-06-21021 June 1999 Special Rept:On 990525,RMS mini-computer Was Removed from Service to Implement Yr 2000 Mod & Was OOS Longer than 72 H Allowed.Caused by Planned Y2K Mods.Preplanned Alternate Sampling Program Was Initiated ML17313A9911999-06-18018 June 1999 Special Rept:On 990510,loose-part Detection Sys Channel 2 Was Declared Inoperable.Caused by Malfunction of Mineral Cable Connector to Accelerometer.Licensee Will Implement Modifications Which Will Enhance loose-part Detection Sys ML17313A9731999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Pvngs,Units 1,2 & 3.With 990608 Ltr ML17313A9281999-05-0707 May 1999 LER 99-004-00:on 990408,PSV Lift Pressures Were Outside of TS Limits.Caused by Lift Pressure Setpoint Drift.Psvs Have Been Tested,Disassembled,Inspected,Reassembled & Certified at Wyle Labs ML17313A9201999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Pvngs,Units 1,2 & 3.With 990512 Ltr ML17313A8951999-04-14014 April 1999 LER 99-003-00:on 990317,required Surveillance Requirement Not Completed Due to Deficient Procedure,Was Determined. Caused by Cognitive Personnel Error.St Procedures Revised to Require Chiller to Be Operating & Oil Temperature Checked ML17313A8921999-04-13013 April 1999 LER 98-003-01:on 980902,discovered That MSSV as-found Lift Pressures Were Outside TS Limits.Caused by Bonding of Valve Disc to Nozzle Seat.Affected Valves Were Adjusted,Retested & Returned to Svc ML17313A8891999-04-0909 April 1999 LER 99-001-00:on 990310,RT on High Pressurizer Pressure Was Noted.Caused by Loss of Heat Removal.Cr Supervisor Was Removed from Shift Duties for Diagnostics Skills Training. with 990409 Ltr ML17300B3071999-03-31031 March 1999 Seismic Portion of Submittal-Only Screening Review of Palo Verde Nuclear Generating Station Units Ipeee. ML17313A8801999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Pvngs,Units 1,2 & 3.With 990412 Ltr ML20207M9231999-03-12012 March 1999 Amended Part 21 Rept Re Cooper-Bessemer Ksv EDG Power Piston Failure.Total of 198 or More Pistons Have Been Measured at Seven Different Sites.All Potentially Defective Pistons Have Been Removed from Svc Based on Encl Results ML20207H7471999-03-10010 March 1999 1999 Emergency Preparedness Exercise 99-E-AEV-03003 ML17313A8361999-03-0101 March 1999 LER 99-001-00:on 990103,TS Violation for Power Dependent Insertion Limit Alarm Being Inoperable.Caused by Personnel Error.Revised Procedure to Clarify How Computer Point Is to Be Returned to Scan Mode.With 990302 Ltr ML17313A8501999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Palo Verde Nuclear Generating Station.With 990311 Ltr ML17313A7791999-02-0505 February 1999 Safety Evaluation Accepting Licensee Rev to Emergency Plan That Would Result in Two Less Radiation Protection Positions Immediatelu Available During Emergencies ML17313A8061999-01-31031 January 1999 Monthly Operating Repts for Jan 1999 for Pvngs,Units 1,2 & 3.With 990218 Ltr ML17313A7701999-01-15015 January 1999 LER 96-008-00:on 960507,inadequate Procedure Results in Nuclear Power Channels Not Calibrated During Power Ascension Tests Occurred.Caused by Deficient Procedure.Procedure Revised ML17313A7381998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Palo Verde Nuclear Generating Station,Units 1,2 & 3.With 990113 Ltr ML20206H2101998-12-31031 December 1998 SCE 1998 Annual Rept ML17313A7031998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Pvngs,Unit 1,2 & 3. with 981209 Ltr ML17313A6701998-11-0404 November 1998 Rev 2 to PVNGS Unit 2 Colr. ML17313A6741998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Pvngs,Units 1,2 & 3.With 981109 Ltr ML17313A6611998-10-24024 October 1998 LER 98-008-00:on 980729,EQ of Electrical Connectors Were Not Adequately Demonstrated.Caused Because Test Was Conducted with Only Single Lv Connector & Without Fully Ranged Inputs. Revised EQ Requirements ML17313A6561998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for PVNGS Units 1,2 & 3.With 981007 Ltr ML17313A5961998-09-14014 September 1998 LER 98-002-00:on 980814,B Train H Recombiner Was Noted Inoperable Due to cross-wired Power Receptacle.Cause of Event Is Under investigation.Cross-wired Power Supply Receptacle for B Train H Recombiner Was re-wired ML17313A5761998-09-0808 September 1998 LER 98-003-01:on 980113,discovered That One Channel of RWT Level Sys Had Failed High.Caused by Water Intrusion Into Electrical Termination Pull Box.Weep Holes Were Drilled Into Bottoms of Pull Boxes Nearest Level Transmitters ML17313A5591998-08-28028 August 1998 LER 98-001-00:on 980730,entered TS 3.0.3 Due to Safety Injection Flow Instruments Being Removed from Svc.Caused by Personnel Error.Transmitters Were Unisolated & Returned to svc.W/980828 Ltr ML20151S0941998-08-21021 August 1998 Rev 6 to COLR for PVNGS Unit 3 ML20151S0861998-08-21021 August 1998 Rev 4 to COLR for PVNGS Unit 1 ML20151S0901998-08-21021 August 1998 Rev 1 to COLR for PVNGS Unit 2 ML18066A2771998-08-13013 August 1998 Part 21 Rept Re Deficiency in CE Current Screening Methodology for Determining Limiting Fuel Assembly for Detailed PWR thermal-hydraulic Sa.Evaluations Were Performed for Affected Plants to Determine Effect of Deficiency ML17313A5401998-08-13013 August 1998 Special Rept:On 980715,declared PASS Inoperable.Caused by Failure of Offgas Flush/Purge Control Handswitch HS0101. Handswitch Replaced & Post Maintenance Retesting Was Initiated ML17313A5301998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Pvgns,Units 1,2 & 3.W/980812 Ltr ML17313A5201998-07-30030 July 1998 LER 98-004-00:on 980630,personnel Discovered That Pressure Safety Valve Had Not Received Periodic Set Pressure Test for ASME Class 1 Pressure Safety Valve.Caused by Personnel Error.Pressure Safety Valve reviewed.W/980730 Ltr ML17313A5791998-07-0707 July 1998 to PVNGS SG Tube ISI Results for Seventh Refueling Outage Mar & Apr 1998. ML17313A5001998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Palo Verde Nuclear Generating Station,Units 1,2 & 3.W/980710 Ltr ML17313A4671998-06-19019 June 1998 LER 98-007-00:on 980520,CR Personnel Observed Flow & Pressure Perturbations on Chemical & Vol Control Sys Letdown Sys.Caused by Cyclic Fatigue Due to Dynamic Pressure Transients.Unit Letdown Piping Replaced ML17313A4521998-06-19019 June 1998 Rev 5 to COLR for Pvngs,Unit 3. ML17313A4501998-06-19019 June 1998 Rev 4 to COLR for Pvngs,Unit 3. ML17313A4131998-06-0505 June 1998 LER 98-006-00:on 980507,determined That Plant Was Outside Design Basis Due to SI Discharge Check Valve Reverse Flow. Check Valve Was Disassembled,Examined & Reassembled, Whereupon Valve Met Acceptance Criteria ML17313A4211998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Pvngs,Units 1,2 & 3.W/980609 Ltr ML17313A3951998-05-26026 May 1998 LER 98-005-00:on 980428,noted That Required Response Time Testing Had Not Been Performed.Caused by Personnel Error. Coached I&C Personnel Responsible for Reviewing Work Authorization Documentation ML17313A3691998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for PVNGS.W/980412 Ltr ML17313A3251998-04-0101 April 1998 LER 98-004-00:on 980304,safety Valves as-found Pressures Out of Tolerance.Cause of Event Is Under Investigation.Three Mssv'S & Psv Will Be Replaced W/Refurbished & Recertified Valves During Refueling Outage U1R7 1999-09-30
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Text
REGULATORY XNFORMATION DISTRIBUTION SYSTEM (RIDS)ACCESSION NBR:9408230102 DOC.DATE: 94/08/08 NOTARIZED:
NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 AUTH.NAME AUTHOR AFFILIATION GRABO,B.Arizona Public, Service Co..(formerly Arizona Nuclear Power p LEVINE,J.M.
Arizona Public Service Co.(formerly Arizona, Nuclear Power RECXP.NAME RECIPIENT AFFILIATION R
SUBJECT:
LER 94-002-01:on 940422,determined that TS 3.1.1.1,3.3.1
&3.9.1 LCO may not ensure that plant operation is maintained within safety analysis.Caused by groundrules adjunct to TS.TS change request is being prepa'red.W/940808 ltr.DXSTRXBDTION CODE: XE22T COPIES RECEIVED:LTR I ENCL Q SIZE://TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.NOTES:STANDARDIZED PLANT 05000528 I RECIPIENT ID CODE/NAME PD4-2 PD TRAN,L INTERNAL: ACRS AEOD/ROAB/
DS P NRR/DE/EMEB NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DSSA/SPLB NRR/PMAS/IRCB-E RES/DSIR/EXB EXTERNAL EG&G BRYCE F J~H NOAC MURPHY,G.A NRC PDR COPIES LTTR ENCL 1 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 RECIPIENT ID CODE/NAME HOLIAN, B AEOD/DS P/TPAB NRR/DE/EELB NRR/DORS/OEAB NRR/DRCH/HICB NRR/DRSS/PRPB NRR/J>SSA/SRXB
-REG~FLE 02 GN4 FILE 01 L ST LOBBY WARD NOAC POORE,W.NUDOCS FULL TXT COPIES LTTR ENCL 1.1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 D U NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE iVASTE!CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT.504-2083)TO ELIMIiNATE YOUR NAME FROM DISTRIBUTION LISTS I'OR DOCUMENTS YOU DON'T NEED!FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 28 ENCL 28 I~4I 1 4' Arizona Public Service Company'PALO VERDE NUCLEAR GENERATING STATION P.O, BOX 52034~PHOENIX, ARIZONA 85072-2034 JAMES M;LEVINE VICE PAE8 I CENT NUCI.EAA PRODUCTION 192-00901-JML/BAG/R JR August 8, 1994 U.S.Nuclear Regulatory Commission ATT: Document Control Desk Mail Station P1-37 Washington, DC 20555
Dear Sirs:
Subject:
Palo Verde Nuclear Generating'Station (PVNGS)Units 1, 2 and 3 Docket No.STN 50-528/529/530 (License No.NPF-41/51/74)
Licensee Event Report 94-002-01 File: 94-020-404 Attached please find supplement 01 to Licensee Event Report (LER)94-002 prepared and submitted pursuant to 10CFR50.73.
This supplement.
reports the identification of an additional Technical Specifications'imiting Condition for Operation that would not ensure Plant operation was maintained within the assumptions of the safety analysis as required by 10CFR50.36.
In accordance with 10CFR50.73(d), a copy of this LER is being forwarded to the Regional Administrator, NRC Region IV.If you have any questions, please contact Burton.A.Grabo, Supervisor, Nuclear Regulatory Affairs, at (602)393-6492.Sincerely, JML/BAG/RR/rv Attachment (all with attachment) cc: W.L.Stewart L.J.Callan K.E.Perkins K.E.Johnston INPO Records Center 9408230102 9'40808 PDR ADOCK 05000528 8 PDR 0 4I 5 LlCENSEE EVENT REPORT (LER)FACII.ITY IthME (I J Palo Verde Unit 1 DOCKET NUMBER (2)PACE 3 o s o o o5 28{QF10'IITLE (c)Technical Specification Limiting Condition for Operation Not Supported by'Safety Analysis EVEtIT DATE IOI DAY MONTH 2 2 0 4 94 94 LER IIVMBER (6)AT NUMBER 0 02 NUMBER 0 1 REPORT DhTE(7)MONTH 0 8 OAY 0 8 OTHER FACIUTIES INVOLVED(6)
FACIUTY NAMES Palo Verde Unit 2 DOCKET NUMBER(S)0 5 0 0 0 5 o60 0 053 0 9 4 Palo Verde Unit 3 OPERATINQ MODE{0)]LEY EL 8 (IOJ tthME 20A02(b)20A05(aN I)(i)20AO5(a)(I)P) 20A05(a)(1)(ii) 20A05(a)(1)(iv) 20A05(a)(1){v) 20AOS(c)50.36(c){I)5026(c)(2) 50.73(a)(2){i) 50.73(a)(2)(il) 50.73(a)(2~w 50.73(a)(2)
{Iv)50.73(a)(2)(v) 50.73{a)(2){vs) 50.73{a)(2)(vll){A) 50.73(a)(2)(vli)(B) 50.73(a){2)(x)
UC EN SEE CONTACT FOR THIS LER (12)AR THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR$1(Check one or more of the kslbvrlng)
(11)73.71{b)73.71(c)OTHER (Speci(pin Abstract briers rnctin Trxh HRC Form 366A)TELEPHONE NUMBER Burton Grabo, Supervisor, Nuclear Regulatory Affairs 602 3 93-64 92 COMPLETE ONE UNE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT{13)CAUSE SYSTEM COMPONENT MANUFAC TURER SYSTEM COMPONENT MANUFAC TURER EPORTABLE TO NPRDS v sax Aprxxc<<c'e<<ccxxci SUPPLEMENTAL REPORT EXPECTED{14)YES (II I rr.ccvriptrtr 8TPEC TED S VShttSSIOH DATE)NO hBSTRhCT (Unit to IGLOO rpecrs;I r r rppoxlmrtrtplihrrn ringtr.space tpprvrrftrrn Iirrs)(16)EXPECTED SUBMSSION DATE{15)MONTH DAY I 004 At approximately 1300 MST on April 22, 1994, Palo Verde Units 1 and 2 were in Mode 1 (POWER OPERATIONS) and Unit 3 was in a refueling outage with the core off loaded eo the spent fuel pool when APS Nuclear Fuel Management personnel determined that Technical Specifications (TS)3.1.1.1, 3.3.1, and 3.9.1 Limiting Conditions for Operation (LCO)may not ensure that plant operation is maintained within ehe assumpeions used in the associated.
safety analysis as required by 10CFR50.36.
On June 7, 1994, while continuing to investigaee the original condition, TS Table 4.3-1 was identified as having a similar-condieion.
An investigaeion into the consequences and implications of these conditions is continuing to be conducted.
A supplement to this LER will be submitted providing this determination based on aceual plant operations.
There have been no previous similar events.
LICENSEE EVENT REPORT (LER)TEXT CONTINuATION FAClllTT NAME Palo Verde Unit 1 TEXT OOCKET NUMBER o 5 o o o 5 2894 LER NUMBER SEQUENTlht.
NUMBER 0 02 REVISION NUMBER 0 1 0 2 PAGE OF 1 0 I.DESCRIPTION OF WHAT OCCURRED: A.Initial Conditions:
At approximately 1300 MST on April 22, 1994, Palo Uerde Units 1 and 2 were in Mode 1 (POWER OPERATIONS) and Unit 3 was in its 4th refueling outage (3R4)with the core (AC)off loaded to the spent fuel pool (ND).B.Reportable Event
Description:
Event Classification:
A condition that resulted in the plant being in an unanalyzed condition.
A condition that resulted in the plant being in a condition not covered by the plant's operating procedures.
APS has recently completed a Technology Transfer Program with the fuel vendor to allow increased involvement in the reload analysis process.As a result, on March 18, 1994, while performing the reload analysis for Unit 3, Cycle 5 and reviewing associated Operating Procedures, APS Engineering personnel (utility, nonlicensed) identified that Technical Specification (TS)Limiting Conditions for Operation (LCO)3.1.1.1, 3.3.1, and 3.9.1 may not ensure that plant operation is maintained within the assumptions used in the'current safety analysis as required by 10CFR50.36.
On April 22, 1994, APS Engineering personnel completed an initial investigation of TSs 3,.1.1.1, 3.3.1, and 3.9.1 Basis, associated safety analysis, and in-place administrative controls.This investigation determined that these TSs did not correctly reflect the current reload analysis and that administrative controls may not have been effective in maintaining Plant operations within safety analysis assumptions.
At approximately 1354 MST, PVNGS informed the USNRC Operations Center of the potential condition.
TSs 3.1.1.1, 3.3.1, and Subcritical CEA Withdrawal Analysis TS 3.1.1.1 requires a 1 percent shutdown margin in Modes 3, 4, and 5 with all Control Element Assemblies (CEA)(RCT) inserted.However, the operating procedures and current safety analysis 4b Ik LICENSEE EVENT REPORT (LER)TEXT CON INUATION FACILITY NAME Palo Verde Unit 1 DOCKETNUMBER 0 5 0 0 0 528 LER NUMBER YEAR~Rc,'EQUENTIAL I)NUMBER<?.".94-002-REVISION NUMBER 0 1 03 PACE OF 1 0 require that the boron concentration be maintained
>Hot Full Power (HFP)All Rods Out (ARO)Equilibrium Xenon Boron Concentration (EXBC)while subcritical (Modes 3, 4, and 5)with the trip breakers (BRK)closed.TS 3.3.1 requires the Core Protection Calculators (CPC)to be operable in Modes 1 and 2.However, the operating procedures and current safety analysis require that the CPC Bypass be functional during any subcritical operation (Modes 3, 4, and 5)with the trip breakers closed."When the discrepancy between TS and the Safety Analysis was identified, the Subcritical CEA Bank Withdrawal Safety Analysis assumed protection was provided by the High Log Power Trip (HLPT)at 1.0 E-2 percent power (except in cases where less than four Reactor Coolant Pumps (RCP)(RCT)(P) are running).When less than four RCPs are running, the analysis assumed protection was provided by the automatic removal of the CPC Bypass at 1.0 E-4 percent power prior to reaching the HLPT setpoint.In June 1991, ABB-Combustion Engineering (ABB-CE)informed APS of an error in the source term used in the Subcritical CEA Bank Withdrawal Safety Analysis.Based on plant procedures, ABB-CE determined that there was no immediate safety concern since the RCS boron concentration would be maintained at or above HFP ARO EXBC.This boron concentration would prevent criticality on any CEA bank withdrawal with all other CEAs completely inserted.ABB-CE'lso stated that either the boron restriction or operation of the CPCs was sufficient to correct for the source term error.Based on this statement, APS changed the Operating Procedures to require the boron restriction or operable CPCs.However, the need for the CPCs to be operable during Modes 3, 4, and 5 with<4 RCPs running was not addressed in the TS.In 1992, the reload groundrule concerning subcritical CEA withdrawal was changed such that the required RCS boron concentration was assumed to prevent criticality on a CEA Shutdown Bank withdrawal.
The HLPT was assumed to protect against a CEA Regulating Bank withdrawal condition.
The CPCs continued to generate a trip in any condition above 1.0 E-4 percent power where<4 RCPs are running (see Section V, Additional Information for a definition/explanation of groundrule).
At this point, the ib 0'\
LICENSEE EVENT REPORT (LER)TEXT CONTINUATION FACILITY NAME Palo Verde Unit 1 OO CKET NUMBER o s o o o 5 28 9 4 LER NUMBER W SEOUENTIAL ii" REVISION kC NUMBER.:.'i NUMBER 002 0 1 PACE 0 40F previously described Administrative Controls (which required one or the other of the above requirements) no longer assured operation within the safety analysis since both the boron restriction and CPCs would be required.The need to change the Operating Procedures was not identified during review of the groundrules.
In February 1994, Nuclear Fuel Management (NFM)identified that the subject groundrule required both the boron restriction and operableCPCs to cover the analysis assumptions.
Corrected Operating Procedures became effective on March 4, 1994.TS 3.9.1 and Mode 6 Boron Dilution Analysis TS 3.9.1 requires either a K-effective of</0.95 or a boron concentration of>/-2150 ppm, whichever is more restrictive, when in Mode 6.The Mode 6 boron dilution analysis (prior to Unit 3 Cycle 5)assumed an initial boron concentration of 4000 ppm.ABB-CE performed previous boron dilution analysis using the Refueling Water Tank (RWT)limits of>4000 ppm and (4400 ppm as specified in TS 3.1.2.5.This analysis assumed that when the refueling cavity was flooded, the RWT would be the source of make-up.APS Engineering personnel performing the reload analysis for Unit 3 determined that procedures do not limit the source of make-up to the RWT.The Unit 3 Boron Dilution Analysis for Mode 6 was analyzed prior to entry into Mode 6 using an initial boron concentration set at the calculated refueling boron concentration.
This boron concentration is more restrictive than a 0.95 K-effective and complies with TS 3.9.1.The analysis verified that the Source Range Monitoring (SRM)Setpoint Ratio of 2.2 remained val'id.The COLR Table 5"Required Monitoring Frequencies for Backup Boron Dilution Detection as a Function of Operating Charging Pumps" for Mode 6 required revision.Reanalysis for the current Unit 1 Core 5 and Unit 2 Core 5 were performed.
This verified that the Mode 6 SRM Setpoint ratio of 2.2 remained valid, but COLR Table 5 required changes.The required monitoring frequencies for backup boron dilution detection in Table 5 of the COLR, for Units 1, 2, and 3 were revised.
!!Cl LIC SEE EVENT REPORT(LER)
TEXT CON UATlON FACII.ITY NAME Palo Verde Unit 1 DOCKET NUMBER LER NUMBER@SEOUENTIAL NUMBEA>'"': REVISION 4 NUM SEA PACE TEXT'5 0 0 0 5 28 94 00 2 0 1 0 5or-10 On June 7, 1994, APS NFM personnel (utility, nonlicsensed) identified an additional condition where the safety analysis used more restrictive requirements than the requirement described in'the TS.TS Table 4.3-1 requires adjustments to linear power level, CPC Delta T Power and CPC nuclear power signals if they differ from the calorimetric by an absolute difference of>2 percent.The ABB-CE letter that transmitted the final CPC/CEAC addressable constants for Unit 3 Cycle 5 requires the calibration tolerance to-be administratively restricted below 30 percent power.This restriction is based on implementation of the interim approach to the CPC power calibration that was first identified by ABB-CE in 1988.Currently the difference between CPC neutron power, CPC Delta T Power, and COLSS primary calorimetric power is between the range of-0.5 percent to+2.0 percent.These requirements are currently administratively controlled.
C.Status of structures, systems, or components that were inoperable at the start of the event that contributed to the event: Not applicable
-no structures, systems, or components were inoperable at the start of the event which contributed to this event.D.Cause of each component or system failure, if known: Not applicable
-no component or system failures were involved.E.Failure mode, mechanism, and effect of each failed component, if known: Not applicable
-no component failures were involved.F.For failures of components with multiple functions, list of systems or secondary functions that were also affected: Not applicable
-no failures of components with multiple functions were involved.
0 ry LICENSEE EVENT REPORT (LER)TEXT CON UATION FACILITY NAME Palo Verde Unit 1 DOCVET NUMBER V EAR g$SEQUENTIAL NUMBER LER NUMBER REVISION NUMBER PAOE TEXT o 5 o o o 5 28 002 0 1 0 6 1 0 G.For a failure that rendered a train of a safety system inoperable, estimated time elapsed from the discovery of the f'ailure until the train was returned to service: Not applicable
-no failures that rendered a train of a safety system inoperable were involved.H.Method of discovery of each component or system failure or procedural error: As discussed in Section I.B, the discrepancies between TS and the current safety analysis were identified as part of the Unit 3 Core 5 Reload Analysis and during a review of an Operating Procedures.
I.Cause of event: In previous reload analysis, the nuclear fuel reload groundrules have been treated as an adjunct to the TS.When groundrules were more restrictive than the current TS, Administrative Controls were used to implement the groundrule restrictions and allow operation of the Plant.The limits defined in the TS were not always revised to reflect the reload analysis if the Administrative Controls were more restrictive.
Because of this, analysis assumptions in the groundrules were not completely consistent with the TS.Secondly, NFM depends upon the cross discipline review of the groundrules to target Operating Procedure changes.These cross discipline reviews did not always identify the impacts that the groundrule changes had on Operating Procedures.
This is likely related to the complexity of the analyses (SALP Cause Code A: Personnel Error).An investigation of this event is continuing to be conducted in accordance with the APS Incident Investigation Program.As part of the investigation, a determination of the cause(s)will continue.If the evaluation results differ from the determinations already identified in this LER, a supplement to this report will be submitted.
0 0 LICENSEE EVENT REPORT (LER)TEXT CONTINUATION FACILITY NAME Palo Verde Unit DOCKET NUMBER LER NUMBER SEOUENZIAL NUMBER REVISION NULIBER PACE TEXT o so ooS28 9 4-0 02 0 1 0 7 OF 1 0 J.Safety System Response: Not applicable
-there were no safety system responses and none were necessary.
K.Failed Component Information:
Not applicable
-no component failures were involved.II.ASSESSMENT OF THE SAFETY CONSEQUENCES AND IMPLICATIONS OF THIS EVENT:~TS 3.1.1.1 and 3.3.1 Control Element Assembly (CEA)Withdrawal from Subcritical Conditions The RCS boron concentration was to be administratively controlled at such a level that the shutdown margin requirement would be met and a subcritical CEA withdrawal would not result in criticality.
Even though the administrative control was incorrect, allowing use of the CPCs rather than maintaining the boron restriction, the CPC Bypass removal at 1.0 E-4 percent power would provide a trip for subcritical CEA withdrawal with<4 RCPs operating.
There have been no rod withdrawal events during the time the Administrative Controls were incomplete.
~TS 3.9.1-Mode 6 Boron Dilution The Boron Dilution analysis for Mode 6 was recalculated using the minimum boron concentration required by TS 3.9.1 for each Unit.When this was done, it was determined that the Mode 6 Source Range Monitoring (SRM)setpoint ratio of 2.2 remained valid for all three Units.~TS Table 4.3-1-CPC Power Calculations The more restrictive requirements for adjustments to linear power level, CPC Delta T power, and CPC neutron power have been administratively controlled since they were first identified by ABB-CE in 1988 and at no time have the safety analysis results been compromised.
0 0 LICENSEE EVENT REPORT (LER)TEXT CONTI UATION FACILITY tIAME Palo Verde Unit 1 DOCKET tiVMBER p 6 p p p 528 94 LERNVMBER Pg SEQUENTIAL NUMBER-002@REVIBION NVMBER 0 1 PAGE 08oF10 Based on the above, the conditions identified in this LER did not result in any challenges to the fission product barriers or result in any releases of radioactive materials.
An.investigation into the consequences and implications of these conditions is continuing to be conducted.
A supplement to th'is LER will be submitted providing this determination based on actual plant operations.
III.CORRECTIVE ACTION: A.Immediate:
TS 3.1.1.1 and 3.3.1 Operating Procedures became effective on March 4, 1994, which required HFP ARO EXBC and operable CPCs during subcritical operations when the CEAs are capable of being withdrawn.
A TS change request is being prepared which will define shutdown margin requirements based on CEA Trip Breaker position rather than CEA position.To eliminate the need for the CPC Bypass in Modes 3, 4, and 5, the TS change will lower the HLPT setpoint to match the removal of the CPC Bypass setpoint.A reference to the minimum boron requirement will also be incorporated into the COLR.These changes are expected to be submitted to the NRC by August 31, 1994.TS 3.9.1 The assumption of 4000 ppm for the initial boron concentration in the Mode 6 Boron Dilution analysis has been changed to the boron concentration required to comply with TS 3.9.1 and the Boron Dilution Analysis for Mode 6 was reanalyzed.
Table 5 of the COLRs, Frequencies for Backup Boron Dilution Detection as a Function of Operating Charging Pumps for Mode 6, has been changed to explicitly include conditions when boron concentrations are<4000 ppm.
0 4l t)?~I' LlCE SEE EVENT REPORT (LER)TEXT CON UATION FACILITY NAME DOCKET NUMBER LER NUMBER PAGE Palo Verde Unit 1 TEXT 0 5 0 0 0 5 YEAR P~.I 9 4-SEOUENTIAL g REVISION NUMBER".oI NUMBER 00 2 0 1 0 9 oF 1 0 B.Action to Prevent Recurrence:
The process for reviewing groundrule changes for impact on Operating Procedures will be reviewed to determine if changes are required to enhance the process.This review is expected to be completed by August 12, 1994.APS NFM personnel are continuing to review the issues identified and the reload analysis process to determine if additional corrective actions that may be required.This review is expected to be completed by August 31, 1994.If information is developed which would affect the safety consequences, root cause, or the reader's understanding or perception of this event, a supplement will be submitted.
An investigation into the consequences and implications of these conditions is continuing to be conducted..
A supplement to this LER will be submitted providing, this determination based on actual plant operations.
This investigation is expected to be completed by August 31, 1994.IV.PREVIOUS SIMILAR EVENTS: There have been no previous similar events.V.ADDITIONAL INFORMATION:
Groundrule Definition:
The groundrule document provides a singular reference and method for communicating detailed assumptions used in the reload analysis that are not captured in other analysis inputs, such as: Performance Objectives, Technical Specifications, Updated Final Safety Analysis Report, Code of Federal Regulations, etc.Groundrule prior to March 4, 1994"Subcritical CEA Withdrawal
-The Reload Analysis Report (RAR)analysis for subcritical CEA Bank Withdrawal shall assume that Reactor Coolant System (RCS)boron concentration shall be maintained such that K-effective will be less than 1.0 upon withdrawal of shutdown Full Length (FL)CEAs when the trip breakers 4l P,'I LICENSEE EVENT REPOFIT (LER)TEXT CON NUATION FACILITY NAME Palo Verde Unit 1 DOCKET NUMBER LEA NUMBER YEAR,'.~SEQUENTIAL g>W NUMBER 4 REVISION NUMBEA PACE TEXT osooo 528 94 002 0 1 10OF1 0 are closed with all other FL CEAs fully inserted." Groundrule after Harch 4, 1994"Subcritical CEA Withdrawal
-The CPCs will be operable when the RTSG is closed.The RCS boron concentration will be maintained at or above the boron concentration required for HFP ARO EX conditions until the shutdown groups are fully withdrawn."
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