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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML17292B7421999-07-20020 July 1999 LER 99-001-00:on 990628,ESF Signal Closed All Eight MSIVs While Plant Was Shutdown.Caused by Failure of Relay RPS-RLY-K10D.Subject Relay Was Replaced & Tested on 990630. with 990720 Ltr ML17292B4451998-10-27027 October 1998 LER 98-012-01:on 980715,failure to Comply with Requirements of TS SR 3.8.4.7 Was Noted.Caused by Inadequate Work Practices.Training Session Was Held with Personnel.With 981027 Ltr ML17284A7561998-09-0303 September 1998 LER 98-013-00:on 980805,ESF Actuations Were Noted Due to Deenergization of Vital Electrical Bus SM-8.Caused by Inadequate Direction in Troubleshooting Plan.Will Conduct Training for Engineering Personnel.With 980903 Ltr ML17284A7571998-09-0202 September 1998 LER 98-014-00:on 980807,completion of TS 3.8.1.F Required Shutdown Due to Inoperability of EDG-2 Was Noted.Caused by Degraded Voltage Regulator for DG-2.Replaced Voltage Regulator & Associated Scrs.With 980902 Ltr ML17284A7551998-09-0202 September 1998 LER 98-015-00:on 980808,discovered Reactor Coolant Pressure Boundary Leak During Shutdown Conditions.Caused by Leakage from Socket Weld (Fwb 63) on Elbow Connection.Failed Piping Connection Was Replaced.With 980902 Ltr ML17284A7311998-08-17017 August 1998 LER 98-012-00:on 980716,determined That 24-month SR 3.8.4.7 Had Not Been Fulfilled within Specified Frequency.Caused by Inadequate Work Practices.License Requested & Received Enforcement Discretion Re Battery Svc test.W/980817 Ltr ML17284A7121998-07-23023 July 1998 LER 98-006-01:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of 10CFR50,App R Calculations for High Impedance Faults.Caused by Inadequate Work Practices.Implemented Procedural Changes ML17284A6951998-07-17017 July 1998 LER 98-011-00:on 980617,ECCS Pump Room Flooding Was Noted Due to FP Sys Pipe Break.Caused by Inadequate Design of FP Sys.Detailed Review of FP Sys Design Was Conducted. W/980717 Ltr ML17284A6961998-07-15015 July 1998 LER 98-010-00:on 980615,TS Required Shutdown Due to Inoperability of TIP Sys Isolation Valve Was Noted.Caused by Improper Installation of TIP Tubing.Reattached Affected Tubing & Inspected Other TIP tubing.W/980715 Ltr ML17284A6731998-07-0101 July 1998 LER 98-009-00:on 980606,nuclear Steam Supply Shutoff Sys Group 3 & 4 Isolations During Testing Was Noted.Caused by Procedural Deficiency.Counseled Individuals Involved in preparation.W/980701 Ltr ML17284A6651998-06-24024 June 1998 LER 98-007-00:on 980530,inadvertent Full Scram & Division 1 ECCS Injection Was Noted.Caused by Failure to Meet Mgt Work Practice Expectation When Encountering Deficient Procedure. Incident Review Board Convened to Review event.W/980624 Ltr ML17284A6641998-06-24024 June 1998 LER 98-008-00:on 980531,inadvertent Full Scram During RPV Leak Testing in Mode 4 Was Noted.Caused by Change in Mgt Techniques.Revised Procedures to Take Into Account Addl Water Head in Pressure Sensing lines.W/980624 Ltr ML17284A6631998-06-19019 June 1998 LER 98-006-00:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of App R Calculations for High Impedance Fault Analysis.Caused Indeterminate. Implemented Procedural Changes Involving Operator Action ML17284A6551998-06-0404 June 1998 LER 98-005-00:on 980506,potential for Failure of RHR Sys Valve to Close on Isolation Signal Was Noted.Caused by Design Deficiency.Caution Tag Was Placed on RHR-V-40 Control Switch to Inform Plant Operators of limitation.W/980604 Ltr ML17284A6421998-06-0101 June 1998 LER 98-004-00:on 980502,determined That Primary Containment Penetration Overcurrent Protection Does Not Meet Reg Guide 1.63 Requirements.Caused by Inadequate Design Changes. Installed Addl Fuse in RHR-MO-9 circuit.W/980601 Ltr ML17292B3281998-04-0909 April 1998 LER 98-002-00:on 980311,reactor Scram & Plant Transient Occurred,Due to Failed Closed Main Steam Isolation Valve. Caused by Loss of Pneumatic Actuating Supply Pressure. Problem Evaluation Request Written for Failure of MS-V-22D ML17292B3291998-04-0909 April 1998 LER 98-003-00:on 980311,WNP-2 Experienced SCRAM Signal as Result of Low Rpv.Caused by Less than post-SCRAM Operational Strategy for Resetting SCRAM Signal in Conditions.Changes in post-SCRAM Operational Strategy implemented.W/980409 Ltr ML17292B2661998-03-0404 March 1998 LER 98-001-00:on 980203,automatic Start of HPCS EDG Was Noted.Caused by Operator Error.Operations Crew Stabilized Plant at Approximately 75% Reactor Power & Investigation of Event Was initiated.W/980304 Ltr ML17292B1111997-11-10010 November 1997 LER 97-011-00:on 971010,HPCS Battery Charger Failed.Caused by Failure of a Phase Firing Control Circuit Board Due to Aging During 7 Yrs of Use.Hpcs Sys Was Immediately Declared inoperable.W/971110 Ltr ML17292B1151997-11-0707 November 1997 LER 97-010-00:on 970906,discovered That TS SR 3.4.5.1 for Identified Portion of RCS Total Leakage Would Not Be Able to Perform within Time Limits of SR 3.0.2.Caused by Inadequate Methods.Method of Meeting SR 3.4.5.1 Established ML17292B0641997-09-24024 September 1997 LER 97-004-01:on 970327,plant Operators Manually Scrammed Reactor as Required by TS Due to Indication of Entry Into Region a of power-to-flow Map.Caused by Inadequate Attention to Detail.Established Event Evaluation teams.W/970924 Ltr ML17292B0241997-08-18018 August 1997 LER 97-009-00:on 970717,discovered Error in Recently Performed Inservice Testing procedure,OSP-TIP/IST-R701. Caused by Procedure Inadequacy.Plant Procedure OSP/TIP/IST-R701 Will Be changed.W/970818 Ltr ML17292B0291997-08-15015 August 1997 LER 97-008-00:on 970716,wire Seal Used to Lock Containment Instrument Air Pressure Control valve,CIA-PCV-2B,found Not Intact.Cause of Misadjustment of CIA-PCV-2B Unknown.Event Will Be Communicated to Plant employees.W/970815 Ltr ML17292B0201997-08-15015 August 1997 LER 97-S01-00:on 970718,failure to Take Compensatory Measure for Inoperative Microwave Security Zone Occurred. Caused by Personnel Error.Training Will Be Conducted W/ Appropriate Members of Security force.W/970815 Ltr ML17292A9481997-07-23023 July 1997 LER 97-007-00:on 970611,voluntary Rept of Automatic Start of DG-1 & DG-2 Was Experienced.Caused by Undervoltage Condition on Electrical Busses SM-7 & SM-8.Circulating Water Pump CW-P-1C Control Switch Placed in pull-to-lock.W/970723 Ltr ML17292A9201997-06-26026 June 1997 LER 97-006-00:on 970527,non-performance of Surveillance Requirement 3.6.1.3.2 for Blind Fanges,Was Noted.Caused Because Misunderstanding of Intent of Specs.Added Five Structural Assemblies for SP.W/970626 Ltr ML17292A8331997-04-28028 April 1997 LER 97-004-00:on 970327,plant Operators Manually Scrammed Reactor as Required by TS Due to Entry Into Region a of power-to-flow Map Following Planned Trip of Single Mfp. Event Evaluation teams,established.W/970428 Ltr ML17292A8311997-04-28028 April 1997 LER 97-005-00:on 970327,valid Reactor Scram Signal Received Due to Low Water Level Condition During Preparations for SRV Testing.Caused by Risks & Consequences of Decisions Not Completely Identified.Restored Water level.W/970428 Ltr ML17292A8251997-04-21021 April 1997 LER 97-003-00:on 970320,notification of Noncompliance W/Ts as TS SRs for Response Time Testing Were Not Being Met for Specified Instrumentation in Rps,Pcis & Eccs.Requested Enforcement Discretion for One Time exemption.W/970421 Ltr ML17292A7431997-03-20020 March 1997 LER 97-002-00:on 970218,determined That Rod Block Monitor (RBM) Calibr Values Were Not Set IAW Tech Specs.Caused by Calibr Procedures Inadequacies.Revised & re-performed RBM Channel Calibr procedures.W/970330 Ltr ML17292A7401997-03-13013 March 1997 LER 97-001-00:on 970211,reactor Water Cleanup Sys Blowdown Flow Isolation Setpoint Was Slightly Above TS Allowable Valve Occurred Due to Calculation Error.Lds Fss LD-FS-15 LD-FS-16 Were Declared inoperable.W/970313 Ltr ML17292A6641997-01-22022 January 1997 LER 96-009-00:on 961220,miscalculation of Instantaneous Overcurrent Relay Settings Resulted in Inoperability of safety-related Equipment.Caused by Utilization of Inappropriate Design.Testing Was completed.W/970122 Ltr ML17292A6461997-01-0606 January 1997 LER 96-008-00:on 961205,failure to Comply with TS Action Requirement for Emergency Core Cooling Sys Actuation Instrumentation Occurred Due to Unidentified Inoperability Condition.Pmr initiated.W/970106 Ltr ML17292A6371996-12-19019 December 1996 LER 96-007-00:on 961122,electrical Breakers Were Not Seismically Qualified in Test/Disconnect Position.Circuit Breaker Mfg Did Not Consider Raced Out Breaker Position During Testing.Relocated Circuit breakers.W/961217 Ltr ML17292A4121996-08-0808 August 1996 LER 96-006-00:on 960709,average Power Range Monitor Rod Block Downscale Surveillance Not Performed Prior to Entry Into Mode 1.Caused by long-standing Misinterpretation of Requirements of Tss.Procedures revised.W/960808 Ltr ML17292A3801996-07-24024 July 1996 LER 96-004-00:on 960624,plant Was Manually Scrammed by Control Room Personnel Due to Reactor Water Level Transient Experienced During Testing of Digital Feedwater Sys.Caused by Programming Error.Sys Was corrected.W/960724 Ltr ML17292A3771996-07-24024 July 1996 LER 96-005-00:on 960624,determined Missed Surveillance Test Re Channel Check of Average Power Range Monitor.Caused by Inadequate Procedures.Revised Surveillance Procedure Re When APRM Checks Must Be performed.W/960724 Ltr ML17292A3641996-07-12012 July 1996 LER 96-003-00:on 960615,required Surveillance Test Not Performed When Required by TS 3.4.1.3.Caused by Inadequate Procedures.Implementing Surveillance Procedure & Reactor Plant Startup Procedures revised.W/960712 Ltr ML17292A3361996-06-20020 June 1996 LER 96-002-00:on 960504,critical Bus SM-8 Lost Power When Supply Breaker 3-8 Tripped.Caused by Personnel Error. Operators Counselled & Procedures revised.W/960620 Ltr ML17292A2861996-05-24024 May 1996 LER 96-001-00:on 960425,inadvertent ESF Actuations Occurred Due to Tripping of Temporary Power Supply to IN-3.Caused by Personnel Error.Operations Restored to IN-3 Loads & Reset ESF actuations.W/960524 Ltr ML17291B0891995-10-19019 October 1995 LER 95-011-00:on 950919,failed to Comply W/Ts SR for RCIC Sys Due to Analysis Deficiency That Resulted in Inadequate Surveillance Test Procedure.Surveillance Procedure Revised to Correct deficiency.W/951019 Ltr ML17291A9021995-07-0707 July 1995 LER 95-010-00:on 950609,HPCS DG Declared Inoperable Due to Discovery That TS Test Method Incomplete.Caused by Inadequate Testing Procedure.Test Procedure for HPCS DG Reviewed & Special Test Procedures written.W/950707 Ltr ML17291A9031995-07-0707 July 1995 LER 95-009-00:on 950607,inadvertent MSIV Closure Occurred During Surveillance Test Due to Poor Communication Between Test Team.Determined That MSIV Closure Not Valid Because Closure Not Triggered by Plant conditions.W/950707 Ltr ML17291A8501995-06-0808 June 1995 LER 95-006-01:on 950405,reactor Scram Occurred During Surveillance Testing Due to Protective Sys Relay Failure. Replaced Failed Relay Before Plant Startup ML17291A8101995-05-12012 May 1995 LER 95-008-00:on 940125,TS Wording Lead to Potential TS Violation.Caused by Lack of Clarity in Ts.Submitted Improved TS for Plant to Provide Addl clarity.W/950512 Ltr ML17291A7841995-05-0505 May 1995 LER 95-007-00:on 950222,emergency Diesel Start Occurred Due to Voltage Transient on BPA Grid.Confirmation Was Received at 17:51 H That Disturbance Had Originated in BPA Grid ML17291A7801995-05-0404 May 1995 LER 95-006-00:on 950405,main Turbine Trip Occurred During Performance of Surveillance Test Due to Protective Sys Relay Failed.Replaced Failed Relay Before Plant startup.W/950504 Ltr ML17291A7851995-05-0303 May 1995 LER 95-005-00:on 950222,inoperable IRM Had Been Relied Upon to Meet TS Requirements During Reactor Startup.Caused by Lack of Neutron Source to Test Instrumentation. Sys Knowledge Gained Will Be incorporated.W/950503 Ltr ML17291A7071995-03-25025 March 1995 LER 95-004-00:on 950226,malfunction in Main Turbine DEH Control Sys Caused All Four High Pressure Turbine Governor Valves to Rapidly Close.Caused by Blown Fuse.Suspected Faulty Circuit Card replaced.W/950325 Ltr ML17291A7011995-03-20020 March 1995 LER 95-002-00:on 950218,automatic Reactor Scram Occurred. Caused by Erroneous Positioning of Control During Performance of Scheduled Periodic Functional Test.Control repositioned.W/950320 Ltr 1999-07-20
[Table view] Category:RO)
MONTHYEARML17292B7421999-07-20020 July 1999 LER 99-001-00:on 990628,ESF Signal Closed All Eight MSIVs While Plant Was Shutdown.Caused by Failure of Relay RPS-RLY-K10D.Subject Relay Was Replaced & Tested on 990630. with 990720 Ltr ML17292B4451998-10-27027 October 1998 LER 98-012-01:on 980715,failure to Comply with Requirements of TS SR 3.8.4.7 Was Noted.Caused by Inadequate Work Practices.Training Session Was Held with Personnel.With 981027 Ltr ML17284A7561998-09-0303 September 1998 LER 98-013-00:on 980805,ESF Actuations Were Noted Due to Deenergization of Vital Electrical Bus SM-8.Caused by Inadequate Direction in Troubleshooting Plan.Will Conduct Training for Engineering Personnel.With 980903 Ltr ML17284A7571998-09-0202 September 1998 LER 98-014-00:on 980807,completion of TS 3.8.1.F Required Shutdown Due to Inoperability of EDG-2 Was Noted.Caused by Degraded Voltage Regulator for DG-2.Replaced Voltage Regulator & Associated Scrs.With 980902 Ltr ML17284A7551998-09-0202 September 1998 LER 98-015-00:on 980808,discovered Reactor Coolant Pressure Boundary Leak During Shutdown Conditions.Caused by Leakage from Socket Weld (Fwb 63) on Elbow Connection.Failed Piping Connection Was Replaced.With 980902 Ltr ML17284A7311998-08-17017 August 1998 LER 98-012-00:on 980716,determined That 24-month SR 3.8.4.7 Had Not Been Fulfilled within Specified Frequency.Caused by Inadequate Work Practices.License Requested & Received Enforcement Discretion Re Battery Svc test.W/980817 Ltr ML17284A7121998-07-23023 July 1998 LER 98-006-01:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of 10CFR50,App R Calculations for High Impedance Faults.Caused by Inadequate Work Practices.Implemented Procedural Changes ML17284A6951998-07-17017 July 1998 LER 98-011-00:on 980617,ECCS Pump Room Flooding Was Noted Due to FP Sys Pipe Break.Caused by Inadequate Design of FP Sys.Detailed Review of FP Sys Design Was Conducted. W/980717 Ltr ML17284A6961998-07-15015 July 1998 LER 98-010-00:on 980615,TS Required Shutdown Due to Inoperability of TIP Sys Isolation Valve Was Noted.Caused by Improper Installation of TIP Tubing.Reattached Affected Tubing & Inspected Other TIP tubing.W/980715 Ltr ML17284A6731998-07-0101 July 1998 LER 98-009-00:on 980606,nuclear Steam Supply Shutoff Sys Group 3 & 4 Isolations During Testing Was Noted.Caused by Procedural Deficiency.Counseled Individuals Involved in preparation.W/980701 Ltr ML17284A6651998-06-24024 June 1998 LER 98-007-00:on 980530,inadvertent Full Scram & Division 1 ECCS Injection Was Noted.Caused by Failure to Meet Mgt Work Practice Expectation When Encountering Deficient Procedure. Incident Review Board Convened to Review event.W/980624 Ltr ML17284A6641998-06-24024 June 1998 LER 98-008-00:on 980531,inadvertent Full Scram During RPV Leak Testing in Mode 4 Was Noted.Caused by Change in Mgt Techniques.Revised Procedures to Take Into Account Addl Water Head in Pressure Sensing lines.W/980624 Ltr ML17284A6631998-06-19019 June 1998 LER 98-006-00:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of App R Calculations for High Impedance Fault Analysis.Caused Indeterminate. Implemented Procedural Changes Involving Operator Action ML17284A6551998-06-0404 June 1998 LER 98-005-00:on 980506,potential for Failure of RHR Sys Valve to Close on Isolation Signal Was Noted.Caused by Design Deficiency.Caution Tag Was Placed on RHR-V-40 Control Switch to Inform Plant Operators of limitation.W/980604 Ltr ML17284A6421998-06-0101 June 1998 LER 98-004-00:on 980502,determined That Primary Containment Penetration Overcurrent Protection Does Not Meet Reg Guide 1.63 Requirements.Caused by Inadequate Design Changes. Installed Addl Fuse in RHR-MO-9 circuit.W/980601 Ltr ML17292B3281998-04-0909 April 1998 LER 98-002-00:on 980311,reactor Scram & Plant Transient Occurred,Due to Failed Closed Main Steam Isolation Valve. Caused by Loss of Pneumatic Actuating Supply Pressure. Problem Evaluation Request Written for Failure of MS-V-22D ML17292B3291998-04-0909 April 1998 LER 98-003-00:on 980311,WNP-2 Experienced SCRAM Signal as Result of Low Rpv.Caused by Less than post-SCRAM Operational Strategy for Resetting SCRAM Signal in Conditions.Changes in post-SCRAM Operational Strategy implemented.W/980409 Ltr ML17292B2661998-03-0404 March 1998 LER 98-001-00:on 980203,automatic Start of HPCS EDG Was Noted.Caused by Operator Error.Operations Crew Stabilized Plant at Approximately 75% Reactor Power & Investigation of Event Was initiated.W/980304 Ltr ML17292B1111997-11-10010 November 1997 LER 97-011-00:on 971010,HPCS Battery Charger Failed.Caused by Failure of a Phase Firing Control Circuit Board Due to Aging During 7 Yrs of Use.Hpcs Sys Was Immediately Declared inoperable.W/971110 Ltr ML17292B1151997-11-0707 November 1997 LER 97-010-00:on 970906,discovered That TS SR 3.4.5.1 for Identified Portion of RCS Total Leakage Would Not Be Able to Perform within Time Limits of SR 3.0.2.Caused by Inadequate Methods.Method of Meeting SR 3.4.5.1 Established ML17292B0641997-09-24024 September 1997 LER 97-004-01:on 970327,plant Operators Manually Scrammed Reactor as Required by TS Due to Indication of Entry Into Region a of power-to-flow Map.Caused by Inadequate Attention to Detail.Established Event Evaluation teams.W/970924 Ltr ML17292B0241997-08-18018 August 1997 LER 97-009-00:on 970717,discovered Error in Recently Performed Inservice Testing procedure,OSP-TIP/IST-R701. Caused by Procedure Inadequacy.Plant Procedure OSP/TIP/IST-R701 Will Be changed.W/970818 Ltr ML17292B0291997-08-15015 August 1997 LER 97-008-00:on 970716,wire Seal Used to Lock Containment Instrument Air Pressure Control valve,CIA-PCV-2B,found Not Intact.Cause of Misadjustment of CIA-PCV-2B Unknown.Event Will Be Communicated to Plant employees.W/970815 Ltr ML17292B0201997-08-15015 August 1997 LER 97-S01-00:on 970718,failure to Take Compensatory Measure for Inoperative Microwave Security Zone Occurred. Caused by Personnel Error.Training Will Be Conducted W/ Appropriate Members of Security force.W/970815 Ltr ML17292A9481997-07-23023 July 1997 LER 97-007-00:on 970611,voluntary Rept of Automatic Start of DG-1 & DG-2 Was Experienced.Caused by Undervoltage Condition on Electrical Busses SM-7 & SM-8.Circulating Water Pump CW-P-1C Control Switch Placed in pull-to-lock.W/970723 Ltr ML17292A9201997-06-26026 June 1997 LER 97-006-00:on 970527,non-performance of Surveillance Requirement 3.6.1.3.2 for Blind Fanges,Was Noted.Caused Because Misunderstanding of Intent of Specs.Added Five Structural Assemblies for SP.W/970626 Ltr ML17292A8331997-04-28028 April 1997 LER 97-004-00:on 970327,plant Operators Manually Scrammed Reactor as Required by TS Due to Entry Into Region a of power-to-flow Map Following Planned Trip of Single Mfp. Event Evaluation teams,established.W/970428 Ltr ML17292A8311997-04-28028 April 1997 LER 97-005-00:on 970327,valid Reactor Scram Signal Received Due to Low Water Level Condition During Preparations for SRV Testing.Caused by Risks & Consequences of Decisions Not Completely Identified.Restored Water level.W/970428 Ltr ML17292A8251997-04-21021 April 1997 LER 97-003-00:on 970320,notification of Noncompliance W/Ts as TS SRs for Response Time Testing Were Not Being Met for Specified Instrumentation in Rps,Pcis & Eccs.Requested Enforcement Discretion for One Time exemption.W/970421 Ltr ML17292A7431997-03-20020 March 1997 LER 97-002-00:on 970218,determined That Rod Block Monitor (RBM) Calibr Values Were Not Set IAW Tech Specs.Caused by Calibr Procedures Inadequacies.Revised & re-performed RBM Channel Calibr procedures.W/970330 Ltr ML17292A7401997-03-13013 March 1997 LER 97-001-00:on 970211,reactor Water Cleanup Sys Blowdown Flow Isolation Setpoint Was Slightly Above TS Allowable Valve Occurred Due to Calculation Error.Lds Fss LD-FS-15 LD-FS-16 Were Declared inoperable.W/970313 Ltr ML17292A6641997-01-22022 January 1997 LER 96-009-00:on 961220,miscalculation of Instantaneous Overcurrent Relay Settings Resulted in Inoperability of safety-related Equipment.Caused by Utilization of Inappropriate Design.Testing Was completed.W/970122 Ltr ML17292A6461997-01-0606 January 1997 LER 96-008-00:on 961205,failure to Comply with TS Action Requirement for Emergency Core Cooling Sys Actuation Instrumentation Occurred Due to Unidentified Inoperability Condition.Pmr initiated.W/970106 Ltr ML17292A6371996-12-19019 December 1996 LER 96-007-00:on 961122,electrical Breakers Were Not Seismically Qualified in Test/Disconnect Position.Circuit Breaker Mfg Did Not Consider Raced Out Breaker Position During Testing.Relocated Circuit breakers.W/961217 Ltr ML17292A4121996-08-0808 August 1996 LER 96-006-00:on 960709,average Power Range Monitor Rod Block Downscale Surveillance Not Performed Prior to Entry Into Mode 1.Caused by long-standing Misinterpretation of Requirements of Tss.Procedures revised.W/960808 Ltr ML17292A3801996-07-24024 July 1996 LER 96-004-00:on 960624,plant Was Manually Scrammed by Control Room Personnel Due to Reactor Water Level Transient Experienced During Testing of Digital Feedwater Sys.Caused by Programming Error.Sys Was corrected.W/960724 Ltr ML17292A3771996-07-24024 July 1996 LER 96-005-00:on 960624,determined Missed Surveillance Test Re Channel Check of Average Power Range Monitor.Caused by Inadequate Procedures.Revised Surveillance Procedure Re When APRM Checks Must Be performed.W/960724 Ltr ML17292A3641996-07-12012 July 1996 LER 96-003-00:on 960615,required Surveillance Test Not Performed When Required by TS 3.4.1.3.Caused by Inadequate Procedures.Implementing Surveillance Procedure & Reactor Plant Startup Procedures revised.W/960712 Ltr ML17292A3361996-06-20020 June 1996 LER 96-002-00:on 960504,critical Bus SM-8 Lost Power When Supply Breaker 3-8 Tripped.Caused by Personnel Error. Operators Counselled & Procedures revised.W/960620 Ltr ML17292A2861996-05-24024 May 1996 LER 96-001-00:on 960425,inadvertent ESF Actuations Occurred Due to Tripping of Temporary Power Supply to IN-3.Caused by Personnel Error.Operations Restored to IN-3 Loads & Reset ESF actuations.W/960524 Ltr ML17291B0891995-10-19019 October 1995 LER 95-011-00:on 950919,failed to Comply W/Ts SR for RCIC Sys Due to Analysis Deficiency That Resulted in Inadequate Surveillance Test Procedure.Surveillance Procedure Revised to Correct deficiency.W/951019 Ltr ML17291A9021995-07-0707 July 1995 LER 95-010-00:on 950609,HPCS DG Declared Inoperable Due to Discovery That TS Test Method Incomplete.Caused by Inadequate Testing Procedure.Test Procedure for HPCS DG Reviewed & Special Test Procedures written.W/950707 Ltr ML17291A9031995-07-0707 July 1995 LER 95-009-00:on 950607,inadvertent MSIV Closure Occurred During Surveillance Test Due to Poor Communication Between Test Team.Determined That MSIV Closure Not Valid Because Closure Not Triggered by Plant conditions.W/950707 Ltr ML17291A8501995-06-0808 June 1995 LER 95-006-01:on 950405,reactor Scram Occurred During Surveillance Testing Due to Protective Sys Relay Failure. Replaced Failed Relay Before Plant Startup ML17291A8101995-05-12012 May 1995 LER 95-008-00:on 940125,TS Wording Lead to Potential TS Violation.Caused by Lack of Clarity in Ts.Submitted Improved TS for Plant to Provide Addl clarity.W/950512 Ltr ML17291A7841995-05-0505 May 1995 LER 95-007-00:on 950222,emergency Diesel Start Occurred Due to Voltage Transient on BPA Grid.Confirmation Was Received at 17:51 H That Disturbance Had Originated in BPA Grid ML17291A7801995-05-0404 May 1995 LER 95-006-00:on 950405,main Turbine Trip Occurred During Performance of Surveillance Test Due to Protective Sys Relay Failed.Replaced Failed Relay Before Plant startup.W/950504 Ltr ML17291A7851995-05-0303 May 1995 LER 95-005-00:on 950222,inoperable IRM Had Been Relied Upon to Meet TS Requirements During Reactor Startup.Caused by Lack of Neutron Source to Test Instrumentation. Sys Knowledge Gained Will Be incorporated.W/950503 Ltr ML17291A7071995-03-25025 March 1995 LER 95-004-00:on 950226,malfunction in Main Turbine DEH Control Sys Caused All Four High Pressure Turbine Governor Valves to Rapidly Close.Caused by Blown Fuse.Suspected Faulty Circuit Card replaced.W/950325 Ltr ML17291A7011995-03-20020 March 1995 LER 95-002-00:on 950218,automatic Reactor Scram Occurred. Caused by Erroneous Positioning of Control During Performance of Scheduled Periodic Functional Test.Control repositioned.W/950320 Ltr 1999-07-20
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML17284A9001999-10-31031 October 1999 Rev 0 to COLR 99-15, WNP-2 Cycle 15,COLR GO2-99-177, LER 99-S01-00:on 990903,failure to Take Compensatory Measure within Required Time Upon Failure of Isolation Zone Microwave Unit,Was Noted.Caused by Personnel Error.Provided Refresher Training on Compensatory Measures.With1999-10-0101 October 1999 LER 99-S01-00:on 990903,failure to Take Compensatory Measure within Required Time Upon Failure of Isolation Zone Microwave Unit,Was Noted.Caused by Personnel Error.Provided Refresher Training on Compensatory Measures.With ML17284A8941999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for WNP-2.With 991012 Ltr ML17284A8801999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for WNP-2.With 990910 Ltr ML17284A8691999-07-31031 July 1999 Monthly Operating Rept for July 1999 for WNP-2.With 990813 Ltr ML17292B7421999-07-20020 July 1999 LER 99-001-00:on 990628,ESF Signal Closed All Eight MSIVs While Plant Was Shutdown.Caused by Failure of Relay RPS-RLY-K10D.Subject Relay Was Replaced & Tested on 990630. with 990720 Ltr ML17292B7271999-06-30030 June 1999 Monthly Operating Rept for June 1999 for WNP-2.With 990707 Ltr ML17292B6961999-05-31031 May 1999 Monthly Operating Repts for May 1999 for WNP-2.With 990608 Ltr ML17292B6641999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for WNP-2.With 990507 Ltr ML17292B6391999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for WNP-2.With 990413 Ltr ML17292B5871999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for WNP-2.With 990311 Ltr ML17292B5571999-01-31031 January 1999 Monthly Operating Rept for Jan 1999 for WNP-2.With 990210 Ltr ML17292B5621999-01-31031 January 1999 Rev 1 to COLR 98-14, WNP-2 Cycle 14 Colr. ML17292B5341999-01-15015 January 1999 Part 21 Rept Re Incorrect Modeling of BWR Lower Plenum Vol in Bison.Defect Applies Only to Reload Fuel Assemblies Currently in Operation at WNP-2.BISON Code Model for WNP-2 Has Been Revised to Correct Error ML17292B5331999-01-15015 January 1999 Part 21 Rept Re XL-S96 CPR Correlation for SVEA-96 Fuel. Defect Applies Only to WNP-2,during Cycles 12,13 & 14 Operation.Evaluations of Defect Performed by ABB-CE ML17292B4791998-12-31031 December 1998 Washington Public Power Supply Sys 1998 Annual Rept. with 981215 Ltr ML17292B5351998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for WNP-2.With 990112 Ltr ML17292B5741998-12-31031 December 1998 WNP-2 1998 Annual Operating Rept. with 990225 Ltr ML17284A8231998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for WNP-2.With 981207 Ltr ML17284A8081998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for WNP-2.With 981110 Ltr ML17292B4451998-10-27027 October 1998 LER 98-012-01:on 980715,failure to Comply with Requirements of TS SR 3.8.4.7 Was Noted.Caused by Inadequate Work Practices.Training Session Was Held with Personnel.With 981027 Ltr ML17284A7831998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for WNP-2.With 981007 Ltr ML17284A7491998-09-10010 September 1998 WNP-2 Inservice Insp Summary Rept for Refueling Outage RF13 Spring,1998. ML17284A7561998-09-0303 September 1998 LER 98-013-00:on 980805,ESF Actuations Were Noted Due to Deenergization of Vital Electrical Bus SM-8.Caused by Inadequate Direction in Troubleshooting Plan.Will Conduct Training for Engineering Personnel.With 980903 Ltr ML17284A7571998-09-0202 September 1998 LER 98-014-00:on 980807,completion of TS 3.8.1.F Required Shutdown Due to Inoperability of EDG-2 Was Noted.Caused by Degraded Voltage Regulator for DG-2.Replaced Voltage Regulator & Associated Scrs.With 980902 Ltr ML17284A7551998-09-0202 September 1998 LER 98-015-00:on 980808,discovered Reactor Coolant Pressure Boundary Leak During Shutdown Conditions.Caused by Leakage from Socket Weld (Fwb 63) on Elbow Connection.Failed Piping Connection Was Replaced.With 980902 Ltr ML17284A7681998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for WNP-2.With 980915 Ltr ML17284A7311998-08-17017 August 1998 LER 98-012-00:on 980716,determined That 24-month SR 3.8.4.7 Had Not Been Fulfilled within Specified Frequency.Caused by Inadequate Work Practices.License Requested & Received Enforcement Discretion Re Battery Svc test.W/980817 Ltr ML17284A7261998-07-31031 July 1998 Monthly Operating Rept for July 1998 for WNP-2.W/980810 Ltr ML17284A7121998-07-23023 July 1998 LER 98-006-01:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of 10CFR50,App R Calculations for High Impedance Faults.Caused by Inadequate Work Practices.Implemented Procedural Changes ML17284A6951998-07-17017 July 1998 LER 98-011-00:on 980617,ECCS Pump Room Flooding Was Noted Due to FP Sys Pipe Break.Caused by Inadequate Design of FP Sys.Detailed Review of FP Sys Design Was Conducted. W/980717 Ltr ML17284A6961998-07-15015 July 1998 LER 98-010-00:on 980615,TS Required Shutdown Due to Inoperability of TIP Sys Isolation Valve Was Noted.Caused by Improper Installation of TIP Tubing.Reattached Affected Tubing & Inspected Other TIP tubing.W/980715 Ltr ML17284A6731998-07-0101 July 1998 LER 98-009-00:on 980606,nuclear Steam Supply Shutoff Sys Group 3 & 4 Isolations During Testing Was Noted.Caused by Procedural Deficiency.Counseled Individuals Involved in preparation.W/980701 Ltr ML17284A6751998-06-30030 June 1998 Ro:On 980617,flooding of RB Northeast Stairwell with Consequential Flooding of Two ECCS Pump Rooms.Caused by Inadequate Fire Protection Sys Design.Pumped Out Water from Affected Areas to Point Below Berm Areas of Pump Rooms ML17284A6641998-06-24024 June 1998 LER 98-008-00:on 980531,inadvertent Full Scram During RPV Leak Testing in Mode 4 Was Noted.Caused by Change in Mgt Techniques.Revised Procedures to Take Into Account Addl Water Head in Pressure Sensing lines.W/980624 Ltr ML17284A6651998-06-24024 June 1998 LER 98-007-00:on 980530,inadvertent Full Scram & Division 1 ECCS Injection Was Noted.Caused by Failure to Meet Mgt Work Practice Expectation When Encountering Deficient Procedure. Incident Review Board Convened to Review event.W/980624 Ltr ML17284A6631998-06-19019 June 1998 LER 98-006-00:on 980520,discovered Discrepancies in Low Voltage Bus Calculations During Review of App R Calculations for High Impedance Fault Analysis.Caused Indeterminate. Implemented Procedural Changes Involving Operator Action ML17284A6551998-06-0404 June 1998 LER 98-005-00:on 980506,potential for Failure of RHR Sys Valve to Close on Isolation Signal Was Noted.Caused by Design Deficiency.Caution Tag Was Placed on RHR-V-40 Control Switch to Inform Plant Operators of limitation.W/980604 Ltr ML17284A6421998-06-0101 June 1998 LER 98-004-00:on 980502,determined That Primary Containment Penetration Overcurrent Protection Does Not Meet Reg Guide 1.63 Requirements.Caused by Inadequate Design Changes. Installed Addl Fuse in RHR-MO-9 circuit.W/980601 Ltr ML17284A6491998-05-31031 May 1998 Rev 0 to COLR 98-14, WNP-2,Cycle 14 Colr. ML17292B4031998-05-31031 May 1998 Monthly Operating Rept for May 1998 for WNP-2.W/980608 Ltr ML17292B3921998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for WNP-2.W/980513 Ltr ML17292B3291998-04-0909 April 1998 LER 98-003-00:on 980311,WNP-2 Experienced SCRAM Signal as Result of Low Rpv.Caused by Less than post-SCRAM Operational Strategy for Resetting SCRAM Signal in Conditions.Changes in post-SCRAM Operational Strategy implemented.W/980409 Ltr ML17292B3281998-04-0909 April 1998 LER 98-002-00:on 980311,reactor Scram & Plant Transient Occurred,Due to Failed Closed Main Steam Isolation Valve. Caused by Loss of Pneumatic Actuating Supply Pressure. Problem Evaluation Request Written for Failure of MS-V-22D ML17292B3371998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for WNP-2.W/980409 Ltr ML17292B2641998-03-0404 March 1998 Performance Self Assessment,WNP-2. ML17292B2661998-03-0404 March 1998 LER 98-001-00:on 980203,automatic Start of HPCS EDG Was Noted.Caused by Operator Error.Operations Crew Stabilized Plant at Approximately 75% Reactor Power & Investigation of Event Was initiated.W/980304 Ltr ML17292B2911998-02-28028 February 1998 Monthly Operating Rept for Feb 1998 for WNP-2.W/980313 Ltr ML17284A7971998-02-17017 February 1998 Rev 28 to Operational QA Program Description, WPPSS-QA-004.With Proposed Rev 29 ML17292B3591998-02-12012 February 1998 WNP-2 Cycle 14 Reload Design Rept. 1999-09-30
[Table view] |
Text
ACCEI ERATO DOCUMENT DISTRIBUTION SYSTEM REGULA'l~ INFORMATION DISTRIBUTIO~YSTEM (RIDS)
.ACCESSION NBR:9302230461 DOC.DATE: 93/02/11 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION POCHE,R.J. Washington Public Power Supply System BAKER,J.W. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION
SUBJECT:
LER 92-006-01:on 910412,plant shutdown due to TS requirement. Caused by inoperable Div 1 DG lube oil sys not D adequately cleaned.Mod to lube oil sump made to eliminate sump leakage.W/930217 ltr.
DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:
TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.
NOTES:
A RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PDS PD 1 1 CLIFFORD,J 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB "1 1 AEOD/ROAB/DSP 2 2 NRR/DE/EMEB 7E 1 1 NRR/DLPQ/LHFB10 1 1 NRR/DOEA/OEAB 1 1 NRR/DRCH/HICB8H 1 1 NRR/DRIL/RPEB10 1 1 NRR/DRSS/PRPB11 2 2 NRR/DSSA/SPLB8D 1 1 N DSSA RXB8E 1 1 NRR/DST/SELB 8D 1 1 REG F E 02 1 1 RES/DSIR/EIB 1 .1 RGN5 FILE 01 1 1 EXTERNAL: EG&G BRYCEiJ.H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 - 1 NSIC MURPHYgG.A 1 1 NSIC POOREgW 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONl'ACT TIIE DOCUMEN'!'ON'I'!'OL L'!- <V ~
ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NA."II.". f!<')M D!STlCIUIJ'f!ON LISTS FOR DOCUMENI'S YOU DON'T NEED!
FULL TEXT CONVERSION REQUIRED TOTAL NUMBER,OF COPIES REQUIRED: LTTR 31'NCL 31
@~i ~
WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 G02-93-038 February 17, 1993 Docket No. 50-397 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555
SUBJECT:
NUCLEAR PLANT WNP-2, OPERATING LICENSE NPF-21 LICENSEE EVENT REPORT NO. 92-006-01 Transmitted herewith is Licensee Event Report No. 92-006-01 for the WNP-2 Plant. This report is submitted in response to the report requirements of 10CFR50.73 and discusses the items of reportability, corrective action taken, and action taken to preclude recurrence. This supplement also provides final results and conclusions from the root cause analysis and updates previously provided -information.
Sincerely, J. W. Baker WNP-2 Plant Manager (Mail Drop 927M)
JWB/RJP/cgeh Enclosure CC: Mr. J. B. Martin, NRC - Region V Mr. R. Barr, NRC Resident Inspector (Mail Drop 901A, 2 Copies)
INPO Records Center - Atlanta, GA Mr. D. L. Williams, BPA (Mail Drop 399) 9302230461 9302ii PDR ADOCK 05000397 S PDR
I IOENsEE EVE% REPQRT'(LER)
ACILITY NAHE (I) DOCKET NUMB R ( ) PAGE (3)
Washin ton Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 I DF ITLE (4) ~ II PLANT SHUTDOWN DUE TO TECHNICAL SPECIFICATION REQUIREMENT CAUSED BY INOPERABLE DIVISION 1 DIESEL GENERATOR EVENT DATE (5) LER NUMBER REPORT DATE (7) OTHER FACILITIES INVOLVED (6)
MONTH DAY YEAR YEAR SEqUENTIAL EV I SION HONTH OAY 'EAR FACILITY NAHES OCKET NUMBERS(S)
NUMBER UHBER 0 4 I 2 9 I 9 1 0 0 6 0 I 0 2 I 1 9 3 P ERAT ING HIS REPORT IS SUBMITTED PURSUANT TO THE REIIUIREMENTS OF 10 CFR 5: (Check one or more of the following) (11 ODE (9) 1 ONER LEVEL 20.402(b) 20.405(C) 50.73(a)(2)(iv) 77.71(b)
(10) 20.405(a)(1)(i) 50.36(c)(1) 50.73(a)(2)(v) 73.73(c) 0.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) THER (Specify in Abstract 20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) elow and in Text, NRC 20.405(a)(1)(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) orm 366A) 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)
LICENSEE CONTACT FOR THIS LER (12)
TELEPHONE NUMBER R. J. Poche, Licensing Engineer REA CODE 5 0 9 7 7 - 4 1 4 5 COMPLETE DNE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE SYSTEH COHPONENT MANUFACTURER EPORTABLE CAUSE SYSTEH COMPONENT MANUFACTURER REPORTABLE 0 NPRDS I'0 NPRDS SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED SUBMISSION HOHTH DAY YEAR ATE (15)
YES (If yes, complete EXPECTED SUBHISSION DATE) NO TRACT OIO At 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on April 12, 1991, a Technical Specification required plant shutdown was initiated due to inoperability of the Division 1 emergency diesel generator (DG1). This action was taken after generator lube oil samples indicated higher than expected wear particle concentration. Cold shutdown was achieved at 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> on April 14. Subsequent disassembly and inspection of the generator revealed that the bearings were in satisfactory condition. Therefore, it is concluded that DG1 was capable of performing its.safety function at the time it was declared inoperable, and that this event had minimal safety significance.
The root causes of this event are: 1) the DG1 generator lube oil system was not adequately cleaned after a previous bearing failure; 2) the generator lube oil system design did not provide adequate access for cleaning and inspection; 3) periodic oil changes recommended by the manufacturer were not adequate to reduce contamination levels following bearing break-in, and 4) welds in the lube oil sumps were not oil tight.
Corrective actions included: installation of an additional lube oil reservoir and improved sight glass for the DG1 thrust bearing oil system, repair of the leak in the thrust bearing oil sump, venting of bearing oil sumps, flushing and cleaning of the bearing lube oil systems, and actions taken to trend diesel generator lube oil condition and perform routine sampling on a more frequent basis.
I LICENSEE EVENT REPOR R)
TEXT CONTINUATION AGILITY NAHE (1) OOCKET NUHBER (2) LER NUHBER (8) AGE (3)
Year umber ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 I 1 006 01 2 OF 8 ITLE (4)
PLANT SHUTDOWN DUE TO TECHNICAL SPECIFICATION REQUIREMENT CAUSED BY INOPERABLE DIVISION 1 DIESEL GENERATOR P~ldi i Power Level - 100 Plant Mode - 1 (Power Operation)
Event De cri i n Beginning on April 12, 1991, at 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> WNP-2 was Shutdown due to inoperability of the Division 1 emergency diesel generator (DG1). This shutdown was initiated because DG1 could not be restored to operability within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> as required by Plant Technical Specifications; however, the shutdown also fell within the planned window for the start of the Spring 1991 Maintenance and Refueling Outage.
On April 5, 1991, at 0733 hours0.00848 days <br />0.204 hours <br />0.00121 weeks <br />2.789065e-4 months <br /> DG1 was started to demonstrate operability per Technical Specification Action Statement 3.8.1.1.a due to DG2 testing. The surveillance was completed successfully, but when the diesel was taken from idle speed to rated speed (900 rpm), the Shift Support Supervisor, a licensed operator, observed that a larger than expected drop to 3/4 of an inch below the low level mark occurred in the north-end thrust bearing oil sight glass of the generator (DG-GEN-DGI). The unit was returned to idle speed and the observed oil level returned to approximately 1/8 to 3/8 of an inch below the low level mark.
The Plant System Engineer was notified and he observed the bearing oil levels with the diesels running in idle. (The DG1 and DG2 design has the generator centered between two diesel engines). DG1 was shutdown and returned to its normal standby configuration and per direction from the System Engineer oil was added to raise the oil level to a level just above the low level mark. The 225 ml of oil added is equal to approximately a 1/8 inch increase at the sight glass. At 1508 hours0.0175 days <br />0.419 hours <br />0.00249 weeks <br />5.73794e-4 months <br /> the scheduled testing for DG2 was completed and it was declared operable. At 1629 DG1 wa's run for one hour with the Plant System Engineer present. During the run the thrust bearing oil level sight glass was video taped. Also, generator vibration and bearing temperatures were monitored. All parameters remained within expected ranges.
Following the run, a generator thrust bearing oil sample was taken and sent to a Supply System vendor for analysis.
On April 10, 1991, the results of the vendor analysis of the thrust bearing oil sample were received and identified a higher than expected concentration of wear particles. This was cause for concern and additional investigation. Based on engineering evaluation and consultation with the analysis laboratory, a new sample from both the south straight roller bearing sump and the north thrust bearing sump of the DGl generator were taken. Then, both bearing oil sumps were flushed by draining and filling each sump three times with new oil, after which another set of oil samples were taken. Beginning at 0418 hours0.00484 days <br />0.116 hours <br />6.911376e-4 weeks <br />1.59049e-4 months <br /> on April ll, 1991, DG1 was run for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> with no indication of abnormal performance. At the completion of the run an additional bearing oil sump sample was taken from each of the two bearing sumps. All the samples were flown by chartered plane to the vendor laboratory for analysis. On April 12, 1991, the results of the vendor analysis of the bearing lube oil samples were received. Although the wear particle concentrations in the thrust bearing lube oil were lower in the post 12-hour run sample than in the sample
LICENSEE EVENT REPORR)
TEXT CONTINUATION FACILITY HAHE (I) OOCKET HUHBER (2) LER HUHBER (8) PAGE (3) umber ev. Ho.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 I 006 01 3 OF 8 ITLE (4)
PLANT SHUTDOWN DUE TO TECHNICAL SPECIFICATION REQUIREMENT CAUSED BY INOPERABLE DIVISION 1 DIESEL GENERATOR taken on April 5, 1991, (see Table 1), the concentrations were still higher than would be expected. Based on the limited amount of lube oil history available for this generator and engineering judgement by Utility and Contract Engineers it was concluded that DG1 could not be relied upon. At 0830 on April 12, 1991, DG1 was declared inoperable. Based on the declaration of DG1 inoperability and the recognition that DG1 would not be restored to operable status within the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Technical Specification Action Statement window, Plant Management determined that WNP-2 would be shutdown to begin the Spring 1991 Maintenance and Refueling Outage.
At 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on April 12, 1991, Plant Operations began reducing reactor power. Maintenance and testing activities scheduled for the outage shutdown were conducted as planned during the shutdown. As previously planned, at 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> on April 13, 1991, Reactor Operators scrammed the reactor. At 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> on April 14, 1991, the reactor reached cold shutdown conditions.
TABLE 1 DG1 THRUST BEARING OIL WEAR PARTICLE CONCENTRATION LEVELS (by direct reading ferrography)
Large Particle Small Particle Total Wear
'2.4 Concentration Concentration Particle Sample Date (greater than Sum/ml) (less than 5um/ml) Concentration 4/5/91 88.4 120.8 4/11/91 56.4 22.2 78.6 (before filland drain) 4/11/91 3.3 0.1 3.4 (after filland drain) 4/11/91 43.1 8.6 51.7 (after 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> run)
Immediate rrective Action
- 1. On April 5, 1991, upon discovery of a possible low level condition in the DG1 generator thrust bearing lube oil system, oil was added and DG1 was run and monitored for vibration, lube oil level, and bearing temperature. Additionally, as an added measure of assurance a DG1 generator thrust bearing lube oil sample was taken after the run and sent to a vendor laboratory for analysis.
LICENSEE EVENT REPORR)
TEXT CONTINUATION AGILITY NAME (1) OOCKET NUMBER (2) LER NUMBER (8) AGE (3)
Year Number ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 1 006 01 4 F B TITLE (4)
PLANT SHUTDOWN DUE TO TECHNICAL SPECIFICATION REQUIREMENT CAUSED BY INOPERABLE DIVISION 1 DIESEL GENERATOR
- 2. On April 5, 1991, the operating procedure for DG1 was revised to specify how the emergency diesel generator is to be shutdown if bearing oil sump levels are found outside of the acceptable range.
- 3. On April 10, 1991, when the results of the analysis of the DG1 thrust bearing lube oil sample taken on April 5, 1991, was received and indicated higher than expected wear particle concentration, both DG1 bearing lube oil systems were flushed by draining and filling each sump three times, DG1 was then run for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and additional lube oil samples were taken and flown to the vendor laboratory for analysis.
- 4. On April 12, 1991, when the results of the analysis of the thrust bearing lube oil samples taken on April 11, 1991, were received and indicated higher than expected wear particle concentrations, DG1 was declared inoperable and an orderly plant shutdown was begun.
u hrEval in n rr iv A in A. her Ev luati n This event is being reported per the requirements of 10CFR50.73(a)(2)(i)(A): "The completion of any nuclear plant shutdown required by the plant's Technical Specifications".
On April 14, 1991, a 1-hour report was made at 1141 hours0.0132 days <br />0.317 hours <br />0.00189 weeks <br />4.341505e-4 months <br />, pursuant to 50.72(b)(i)(A) "The Initiation of any Nuclear Plant Shutdown Required by the Plant's Technical Specifications" to the Bethesda Operations Center. This report was delayed by the circumstances surrounding the schedule for the annual refueling outage. The shutdown for the refueling outage was originally scheduled for the period between April 12, 1991, and April 19, 1991. In fact, the plan as of April 11, 1991, was to continue to run through April 19, 1991, to help meet the regional energy demand. Direction was given to initiate the planned outage shutdown schedule at 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on April 12, 1991. The shutdown fell within the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> out of service window allowed by Technical Specification Action Statement 3.8.1.1.a.
- 2. At the time of the April 5, 1991 event, a Plant Procedure was in place which essentially stated that if the oil level decreased to less than 3/8u below the sight glass low level mark to take immediate action to secure the unit (disable from start and declare unit inoperable). For the April 5, 1991 event, the diesel had been running for a few minutes when the low sight glass oil level for the generator thrust bearing was first noticed and measured. The Shift Support Supervisor present at the DG left the room (due to high noise in the room) and called the Control Room Supervisor to discuss the situation. A decision was made to take the diesel back to idle speed at which point the oil level. returned to the allowable range. The period between first discovering the low oil level and taking the DG to idle speed is
'stimated to have been from 2 to 5 minutes. The intent of the above procedure instruction
LICENSEE EVENT REPORTR)
TEXT CONTINUATION AGILITY NAME (I) OOCKET NUMBER (2) LER NUMBER (8) AGE (3) ear umber ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 5"
I 006 01 OF 8 ITLE (4)
PLANT SHUTDOWN DUE TO TECHNICAL SPECIFICATION REQUIREMENT CAUSED BY INOPERABLE DIVISION 1 DIESEL GENERATOR was to immediately shutdown the DG; however, the Plant Operators believed that they were following the procedure and were taking actions to "immediately secure the unit".
Immediately following the event, the procedure was revised to clarify the method of shutdown (depress the emergency stop button).
- 3. The DGl generator was manufactured by the NEI Peebles Company (previously Electric Products Company), serial number 17310200-200. The Diesel Generator Unit was purchased from Stewart and Stevenson Inc. The generator was shipped off-site on April 16, 1991, for disassembly and inspection of the bearings to determine the root cause of the high concentration of wear particles in the thrust bearing lube oil system. Two consulting firms experienced in performing failure analyses were contracted to assist the Supply System staff in determining the root cause of the high wear particle concentration in the thrust bearing lube oil.
- 4. Disassembly and inspection of the DG1 generator bearings and associated lube oil systems revealed that although the wear particle concentration in the bearing oil systems was higher than expected, the bearings were not functionally effected by the oil impurities and DG1 could have fulfilled it's safety function if required.
- 5. The bearing inspection revealed two areas where design improvements, some previously identified in LERs 90-012-00 and 90-012-01, were possible.
- a. It has been observed that the DG1 generator bearing lube oil tended to foam during operation. In an effort to reduce or eliminate this foaming, the tangs on the lock washer for each bearing were machined down approximately 3/8 of an inch since they were suspected of contributing to the foaming problem. In prior discussions, the bearing manufacturer stated that foaming would not appreciably impact expected bearing life.
- b. The second area of improvement was the discovery at an air volume trapped in the upper portion of the oil sump when the oil is at or above the high level. This air volume could change as a function of temperature and possibly as a function of turbulence in the oil. This may have been the cause of the low level observed'at the thrust bearing sight glass during the April 5, 1991 event.'his air volume has been vented to the rest of the lube oil system in an effort to reduce the probability of lube oil level transients caused by thermal expansion and contraction of the oil.
LICENSEE EVENT REPORR)
TEXT CONTINUATION AGILITY NAME (1) OOCKET NUMBER (2) LER NUMBER (8) PAGE (3)
Year umber ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 1 006 01 6 OF 8 ITLE (4)
PLANT SHUTDOWN DUE TO TECHNICAL SPECIFICATION REQUIREMENT CAUSED BY INOPERABLE DIVISION 1 DIESEL GENERATOR
- 6. A leak in the thrust bearing lube oil system that was being monitored and tracked by the Supply System but which had not been specifically located, was positively located. On each bearing lube oil system the weld joint where the air channel meets the bottom of the bearing bore were not oil tight and allowed a small amount of oil to leak. A modification was made
. to restore the leak tightness of the lube oil systems.
- 7. The root causes identified for this event are:
ao Personnel - The DG1 generator lube oil system was not adequately cleaned after the 1990 bearing failure and resulting repair work. This resulted in excessive debris in the lube oil systems of both bearings. During the 1990 DG1 repairs, the thrust bearing oil sump was steam cleaned twice and inspected, however, due to the access problems this effort was not sufficient to preclude this event.
- b. Equipment Design - The design of the emergency diesel generator bearing lube oil systems does not provide access for adequate cleaning and inspection.
C. Maintenance - Annual oil changes recommended by the manufacturer were not adequate to reduce particulate contamination levels following bearing break-in. Also, there was no program for routine sampling and trending of lube oil condition.
- d. Equipment - Manufacturing Error - The welds at the upper edge of the air passages through the lubricating oil sumps were not oil tight and thus did not comply with the design drawings.
- 8. The inoperability of DG2.in order to do the quarterly pole drop test was the direct cause of DG1 being operated; however, the inoperability of DG2 did not contribute to this event.
There were no other structures, systems or components inoperable at the start of this event which contributed to this event.
- 9. 'G2 has not experienced generator lube oil problems similar to those described in this report for DG1. Prior to this event, the bearings on DG2 typically ran cooler, experienced less lube oil foaming, did not evidence lube oil leakage, and did not experience lube oil level transients similar to those associated with DG1. The DG2 operating history, combined with knowledge gained from disassembly and inspection of DG1, provides confidence that DG1 and DG2 are both operable and fully capable of performing their safety function. As a note, neither DG1 nor DG2 have experienced generator bearing problems since the time when this event occurred, and operating temperatures for generator bearings associated with DG1 have decreased as a result of actions taken in response to this event.
LICENSEE EVENT REPORR)
TEXT CONTINUATION AGILITY NAME (1) DOCKET NUMBER (2) LER NUMBER AGE (3)
(8)'mber ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 i 006 01 7 OF 8 ITLE (4)
PLANT SHUTDOWN DUE TO TECHNICAL SPECIFICATION REQUIREMENT CAUSED BY INOPERABLE DIVISION 1 DIESEL GENERATOR B. Further orrective Action An additional lube oil reservoir was installed for the DG1 thrust bearing with a new additional sight glass to make it to easier to read the oil level. The additional reservoir provides a greater volume of oil within the acceptable bearing operating range, approximately 1200 ml versus the previous 250 ml. The new sight glass will provide better access and visibility for personnel monitoring the oil sump level. The increase in the oil sump capacity within the control band was a corrective action planned as a result of the event reported in LER 90-012-00.
- 2. The bearing lube oil systems were thoroughly cleaned and flushed in an effort to reduce the level of impurities in the sump, including wear particles. It is believed that this extensive cleaning overcame the cumbersome design that made cleaning so difficult.
- 3. The generator bearing lube oil sumps for DG1 were drained and refilled after an appropriate bearing break-in period.
- 4. The bearing lube oil trapped air pockets were vented to the remainder of the lube oil system.
- 5. A modification to the lube oil sump was made to eliminate the sump leakage.
- 6. A preventative maintenance task has been scheduled to perform trending of diesel generator lube oil condition and routine sampling on a semi-annual basis under the Lubrication Oil Analysis Program.
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At the time DGl was declared inoperable the plant was in Operating Condition 1, Power Operation, at 100% of rated power. The redundant emergency diesel generator (Division 2), the emergency diesel .
generator supporting the high pressure core spray system (Division 3), and both off-site power sources were all operable. Additionally, the subsequent inspection of the DG1 generator bearings revealed that the generator was capable of performing it's safety function at the time it was declared inoperable. This event had limited safety significance since the electrical power sources, including DG1, required to mitigate postulated accidents were available and capable of performing their safety functions at the time of the plant shutdown. The conservative decision to declare DG1 inoperable ensured that plant safety was mairitained.
LICENSEE. EVENT REPORTR)
TEXT CONTINUATION FACILITY NAME (1) OOCKET NUMBER (2) LER NUMBER (8) PAGE (3)
Year umber ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 I 006 01 8 OF 8 ITLE (4)
PLANT SHUTDOWN DUE TO TECHNICAL SPECIFICATION REQUIREMENT CAUSED BY INOPERABLE DIVISION 1 DIESEL GENERATOR imil r Even On May 27, 1990, the DG1 generator experienced failure of both bearings due to inadequate lubrication of the thrust bearing during outage testing. This failure was voluntarily reported in LERs 90-012-00 and 90-012-01.
EIIS Information EII Reference Text Reference ~Stem ~om onen Division 1 Emergency Diesel Generator (DG1) ED Division 2 Emergency Diesel Generator (DG2) ED Division 1 Emergency Power System ED Generator ED GENI