|
---|
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
[Table view] |
Text
LICENSEE EVENT REPORT (LER)
FACILITYNAME (I) DOCKET NUMBER (2) PACE 3 TITLE (8)
Palo Verde Unit 1 osooo528>or09 Snubber Testing not in Accordance with Technical S ecifications EVENT DATE (5), LER NUMBER (8) REPORT DATE P> OTHER FACIUTIES INVOLVED(8)
MONTH DAY YEAR FACIUTY NAMES DOCKET NUMBER(S)
NUMBER NUMBER MONTH DAY Palo Verde Unit 2 0 5 0 0 0 5,2 Palo Verde Unit 0 5 0' 0 5 3 f: (Cheek one or more ol Ihe Iollowlno) (11) 9'PERATINO
.THIS REPORT IS SUBMIITEDPURSUANT TO THE REOUIREMENTS OF 10 CFR MODE (8)
] 20A02(b), 20AOS(e) 50.73(a)(2) (Iv) 73.71(b)
POWER 20AOS(a)(1)(I) 5046(e)(1) SO.73(a)(2)(v) 73.71(e)
LEVEL (10) 20AOS(a)(1)(II) 50.36(e)(2) 50.73(a)(2)~ OTHER (SpeettytnAbetreet below anrtin Terrb HRC %%dmr 20AOS(a)(1+i) 50.73(a)(2)(I) 50.73(a)(2) yS)(A). 366A) 20AOS(a)(1)(tv) 50.73(a) (2)(II) 50.73(a)(2)(m)(B) 20AOS(a)(1)(v) 50.73(a)(2)(tii) 50.73(a)(2)(a)
LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER Thomas R. Bradish, Manager, Nuclear Regulatory Affairs COMPLETE ONK LIIIEFOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) 602393 5'421 MANUFAC- EPORTABIE MANUFAC CAUSE SYSTEM COMPONENT TURER TO NPRDS. CAUSE SYSTEM COMPONENT TURER SUPPLEMENTAL REPORT EXPECTED (I 8) MONTH DAY YEAR EXPECTED SUB 880SION DATE (15)
YES (llyen oonplete EXPEC7ED SUSMISSIOH DATE) NO ABSTRACT (Urn(I to 1400 epaeea 7 eappredmatety stteen ebr0teepaee typevrrt Iten Farce J (16)
On May 12, 1993, at approximately 1330 MST, APS Management and the NRC discussed APS'nterpretation of Technical Specification 4.7.9.e, for snubber testing. APS concluded that it had incorrectly interpreted the Technical Specification. Additionally, APS had not informed the NRC Regional Administrator that the surveillance requirement, would be implemented differently than previously identified.
Palo Verde Units 1, 2, and 3 entered the ACTION for Limiting Condition for Operation 3.7.9,,at approximately 1330 MST on May 12, 1993, and a Notice of Enforcement Discretion was requested. At approximately 1400 MST on May 14, 1993, APS was notified of the Commission's intent to exercise discretion in enforcing compliance with the ACTION statement of TS 3.7.9, until the NRC takes action on a request for a license amendment.
There have been no previous similar events reported pursuant to 10CFR50.73.
9308060303 930728 PDR ADOCK 05000528 8 ,PDR,,
0 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITYNAME DOCKET NUMBER LER NUMBER PACE YEAR SEQUENTIAL @'I REVISION NUMBER NUMBER Palo Verde Unit 1 osooo528 0 0 7 0 2 0 2 OF 0 9 DESCRIPTION OF WHAT OCCURRED:
A. Initial Conditions:
At approximately 1330 MST on May 12, 1993, Palo Verde Units 1 and 3 were in Mode 1 (POWER OPERATION) operating at 100 percent power.
Unit 2 was in Mode 6 (REFUELING) with cold loop temperature at approximately 87 degrees Fahrenheit.
B. Reportable Event Description (Including Dates and Approximate Times of Major Occurrences):
Event Classification: Operation prohibited by the plant's Technical Specifications.
On May 12, 1993, APS Management (utility, non-licensed) and the NRC discussed APS'nterpretation of Technical Specification (TS)
Surveillance Requirement (SR) 4.7 '.e. APS concluded that it had incorrectly interpreted TS SR 4.7.9.e. Additionally, APS had not informed the NRC Regional Administrator that snubber testing would be implemented differently than previously identified. At approximately 1330 MST on May 12, 1993, Palo Verde Units 1, 2, and 3 entered the ACTION for Limiting Condition for Operation (LCO) 3.7.9.
TS LCO 3.7.9, states in part "...all hydraulic and mechanical snubbers shall be operable...." [Snubbers on non-safety systems may be excluded related systems.]
if The their failure does not adversely affect safety-requirement is applicable in all MODEs for snubbers located on systems required to be OPERABLE in that MODE.
The LCO ACTION states in part "...with one or more snubbers inoperable on any system, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> replace or restore the inoperable snubber(s) to OPERABLE status...or declare the attached system inoperable...follow the ACTION statement for that system."
SR 4.7.9, states in part "...each snubber shall .be demonstrated OPERABLE by performance of the following augmented inservice inspection program and the requirements of SR 4.0.5."
4.7.9.a. defines Snubber Type as "...of the same design and manufacturer, irrespective of capacity...." [The PVNGS Snubber Testing program identifies 5 snubber groups.
The program was implemented with three snubber types:
PSA mechanical, Steam Generator hydraulic, and Reactor Coolant Pump hydraulic.]
4,7.9.e. States in part " ..snubbers shall be tested using one
~
of the following sample plans. The sample plan shall
L'ICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACIUly NAME DOCKET NUMBER LER NUMBER PACE yEAR "~ SEOUENTIAI. P:. REVISION NUMBER lN NUMBER Palo Verde Unit 1 0 5 0 0 0 5 23 9 3 0 0 7 0 2 0 3oF 0 9 be selected prior to the test period and can not be changed during the test period. The NRC Regional Administrator shall be notified in writing of the sample .plan selected prior to the test period...,"
[The NRC Regional Administrator had been informed of APS'ntentions to use .sample plan 4.7.9.e.2, (References 1,2,3). APS did not identify a different sample plan for hydraulic snubber testing.]
4.7.9.e.l). States in part "...at least 10 percent of the total of each type of snubber shall be functionally tested...for each snubber of a type that does not meet .the functional test acceptance criteria...an additional 10 percent of that type of snubber shall be functionally tested until no more failures are found or. until all snubbers of that type have been functionally tested; or,..." [PVNGS hydraulic snubber testing meets this,SR except for random selection.]
4.7.9.e.2). States in part "...a representative sample of each type of snubber shall be functionally tested in accordance .with figure 4.7-1. If at any time the point plotted falls in the "Reject" region all snubbers of that type shall be functionally tested. If at any time the point plotted falls in the "Accept" region, testing of snubbers of that type may be terminated. When the point plotted lies in the "Continue Testing" region, additional snubbers of that type shall be tested until the point falls in the "Accept" region or the "Reject" region, or until all snubbers of that type have been tested; or...."
[Testing of hydraulic snubbers did not meet this sample plan although the NRC Regional Administrator had been informed that it would.]
e.3). Not used at PVNGS.
4.7.9. States in part "...The representative sample...shall be randomly'elected from the snubbers of each type...representative of the various configurations, operating environments, range of size, and capacity of snubbers of each type...." [PVNGS selected its sample for mechanical snubbers from the population that had not been tested. Previously failed snubbers were retested as required. Snubbers that tested acceptable were removed from the test population. Because of the
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION'ACILITY NAME DOCKET NUMBER LER NUMBER PAGE YEAR g: SEQUENTIAL Cg REVISION NUMBER I'I': NUMBER Palo Verde Unit 1 o s o o o 5 2 89 3 0 0 ?, 0 2 04oF09 fev number of hydraulic snubbers, specific steam generator .(AB)(SG) snubbers and'eactor Coolant Pump (AB)(RCP) snubbers vere scheduled to be tested each outage,],
The PVNGS. Snubber Testing Program is described in Administrative Control Procedure 73AC-9ZZ01 "Testing and Control of PVNGS Snubbers." This procedure describes the five (5) snubber groups as follows:
PSA 1/4 and 1/2 size Mechanical Snubbers (small)
PSA 1, 3, and 10 size Mechanical Snubbers (medium)
PSA 35 and 100 size Mechanical Snubbers (large)
SG Hydraulic Snubbers RCP Hydraulic Snubbers Mechanical Snubbers PVNGS implemented the mechanical snubber .testing program by treating all mechanical snubbers as one type with three groups: small, medium, and large., 'PVNGS believed this was a correct interpretation since all mechanical snubbers at PVNGS are Pacific Scientific Arrestors (PSA). The PVNGS program considered all sizes to have the same design features. This is contrary to the requirements of TS SR 4.7'.9.e.
H draulic Snubbers Each unit has 12 hydraulic snubbers, four (4) SG and eight (8) RCP. To implement TS SR 4.7.9.e.2, as docketed to the Regional Administrator, all 12 hydraulic snubbers would require testing each outage. PVNGS tested only one of each type (2 total) during each outage. PVNGS did not notify the Regional Administrator that PVNGS'rocedures implemented a test plan meeting SR 4.7.9.e.l, except for random sample requirements.
Sam le Selection Although the selection of mechanical snubbers for testing at PVNGS was representative, it was not completely random.
Snubbers that failed the acceptance criteria vere repaired or replaced and retested during the next testing, period as required. Snubbers that tested acceptable were not, placed back int:o t:he population for possible selection during a subsequent test period. Although t'e method used by PVNGS would ensure all snubbers would eventually be tested, it did
0 il i
LICENSEE EVENT REPORT,(LER) TEXT CONTINUATION FACILITYNAME DOCKET NUMBER LER NUMBER PACE c~I SEQUENTIAL g@~ REVISION cV> NUMBER NUMBER Palo Verde Unit 1 5 2 89 3 0 0 7 0 2 0'5oFO 9 not meet the random selection criteria.
Hydraulic snubbers are scheduled for testing so that in 8 outages, the entire population of SG snubbers is tested twice and the entire population of RCP snubbers is tested once. This was done to ensure all snubbers are tested while maintaining radiation exposures As Low As Reasonably Achievable (ALARA),
C. Status of structures,,systems, or components that were inoperable at the start of the event that contributed to the event:
Other than the snubbers identifi'ed in Section I.B., that were administratively inoperable due to improperly interpreting the TS SR, no other 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:
This LER identifies a program failure and not. an equipment failure. All snubbers which failed surveillance testing were repaired or replaced and retested as required. No component or system failures were involved.
E. Failure known:
mode, mechani'sm, and effect of each failed component, if Failures of snubbers fall into five general modes as discussed below:
Design or Manufacturing-Failures resulting from a potential defect in manufacturing or design that gives cause to suspect other snubbers. This includes failures of any snubber that fails to withstand the environment or application for which it was designed.
Application induced-Failures resulting from environmental conditions or application of the snubber for which designed or qualified.
it has not been Maintenance, Repair, or Installation-Failures that result from damage during maintenance, repair, or installation activities, the nature of
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACIlITYN AME DOCKET NUMBER LER NUMBER PAGE YEAR @I SEOUEN TIAI.;,I", REVISION NUMBER, >4 NUMBER Palo Verde Unit 1 osooo528 9 3 00,7 0'206 OF. 0 9 which causes other snubbers to be suspect.
~ Isolated-The nature of the failure does, not lend other snubbers to be suspect, for example, failures resulting from damage during installation (i.e., missing pins, dropping equipment or tools on the snubber).
~ Unexplained-Failures that can not be categorized as design or manufacturing,,maintenance, repair, installation, application induced, or isolated. This category includes all failures for which the cause of the failure can not be determined.
There are three mechanisms of failure:
~ Breakaway or Drag-The force that will initiate motion or the force that will maintain low velocity displacement respectively..
Lockup is a breakaway or drag failure which exceeds 20 percent of rated load.
~ Activation-The function of a snubber that restrains movement when undergoing telescoping acceleration.
~ Release Rate The rate of axial snubber movement under load after activation (applicable to hydraulic snubbers only).
An evaluation is performed for snubbers which fail the functional test acceptance criteria. This evaluation determines or components to which the snubbers were attached could be damaged if systems due to the inoperable snubber. There has only been one area identified where the calculated stresses exceeded those allowed by the American Society of Mechanical Engineers (ASME) Code. This occurred on Reactor Coolant System Drain Lines RC070 and RC071.
Failures of snubbers on these lines occurred in Units 2 and 3.
Lines RC070 and RC071 were visually and nondestructively tested.
No abnormal conditions or indications of overstressing were found.
Inspection of piping and supports revealed that no damage had occurred.
!~ 0 S, s I)
LICENSEE'EVENT REPORT (LER) TEXT CONTINUATION FACILITYNAME DOCKET NUMBER LER NUMBER PAGE SEQUENTIAL REVISION NUMBER NUMBER Palo Verde Unit 1 os o o o 5 28 9 3 0 0 7 0 2 0 7OFO 9 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.
G. For a failure that rendered a train of a .safety system inoperable, estimated time elapsed from the discovery of the failure 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:
Unit 2 was in a refueling outage performing required snubber testing. Because of the Unit 2 snubber failures, an increase in sampling was required. During the selection of the additional snubbers by APS Engineering personnel (utility, non-licensed), the NRC Resident Inspector (non-utility, non-licensed) questioned the selection methodology and TS testing requirements. Subsequently, as discussed in Section I.B, APS concluded that it had incorrectly.
interpreted the Technical Specification.
Cause of Event:
This condition was caused by incorrectly interpreting TS SR 4.7.9.e, and failing to recognize and inform. the NRC Regional Administrator that the SR would be implemented differently from previously identified (SALP Cause Codes A: Personnel Error).
This incident is being investigated in accordance with the APS Incident 'Investigation Program. If information is developed which would affect the reader's understanding or perception of this event, a supplement will be submitted.
,Safety System Response:
Not applicable - there were no safety system responses and none were necessary.
K. Failed Component Information:
Pacific Scientific Arrestor Models PSA-1/4, PSA-1/2, PSA-l, PSA-3, PSA-10, PSA-35, and PSA-100
k LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITYNAME DOCKET NUMBER LER NUMBER PACK YEAR SEQUENTIAL ~~g REVISION NUMBER NUMBER Palo Verde Unit 1 0 5 0 0 O'S 2 Sq 3 On 7 .0 2 0 8 OF n 9 II. ASSESSMENT OF THE SAFETY CONSEQUENCES AND IMPLICATIONS OF THIS EVENT:
No release of radiological effluent or exposure to member(s) of the public resulted from this event. APS Engineering .personnel have completed a review of the previous snubber testing conducted at PVNGS and concluded that sufficient testing was performed to assure that the snubbers can perform their intended function.
APS has concluded there is no significant safety implicati'ons to operating PVNGS'nits 1, 2, and 3 as a result of the noncompliance with TS SR 4.7.9.e. The purpose of snubbers is to protect the piping systems during seismic events while allowing thermal growth without overstressing the piping.. For snubbers not meeting the acceptance criteria during testing, stress calculations have been performed to determine if imposed stresses exceeded Code allowable stresses.
was performed with the snubbers in the as-found condition. With the This exception of the Reactor Coolant System Drain Lines RC070 and RC071, APS Engineering personnel determined that the piping was not overstressed and that the snubbers, while degraded, did not challenge the operability of piping or components. Lines RC070 and RC071 were visually and nondestructively examined. No abnormal conditions or indications of overstressing were found. Therefore, the consequences are no different than previously analyzed in the PVNGS Updated Final Safety Analysis Report for snubber failures. The probability and types of failures remain the same.
III. CORRECTIVE ACTION:
A. Immediate:
In accordance with TS 4.0.3., failure to perform a surveillance requirement constitutes noncompliance with the OPERABILITY requirements for a LCO and requires the entry into the associated ACTION statement. As discussed above, PVNGS entered the ACTION statement for TS 3.7.9., at approximately 1330 MST on May 12, 1993. This 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> action period would have ended at approximately 1330 MST on May 15, 1993, when PVNGS'nit 1 and Unit 3 would have been required to shutdown in accordance with TS 3.0.3. A Notice of Enforcement Discretion from PVNGS'nit 1, 2, and 3 TS Limiting Condition for Operation ACTION statement was requested from and subsequently granted by the Commission at approximately 1400 MST on 'May 14, 1993.
Ji Ji,
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITYNAME DOCKET NUMBER. LER NUMBER PAGE YEAR SEQUENTIAL <:~ REVISION NUMBER NUMBER Palo Verde Unit 1 5 2 8 OF B. Action to Prevent Recurrence:
The PVNGS Snubber Testing program will be revised -to correctly implement the TS requirements prior to commencing the next testing cycle.
An investigation of this event is being conducted according to the APS Incident Investigation Program. Additional actions. to prevent recurrence may be identified based upon the results, of the investigation. If additional actions are identified which the reader's understanding or perception of this event, a would'ffect supplement will be submitted.
IV. PREVIOUS SIMILAR EVENTS:
There have been no previous similar events reported pursuant to 10CFR50.73.
V. ADDITIONAL INFORMATION References (1) Letter 161-00296, dated June 22, 1987-, from J.G..Haynes, APS to Mr. John B. Martin, USNRC.
Subject:
Functional Testing of Snubbers. [Unit 1]
(2) Letter 161-00469, dated August 31, 1987, from J.G. Haynes, APS to Mr. John B. Martin, .USNRC.
Subject:
Functional Testing of Snubbers. [Unit 2]
(3) Letter 161-01612, dated January 12, 1989, from D. B. Karner, APS to the Document Control Desk.
Subject:
Functional Testing of Snubbers. [Unit 3]
0 0