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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
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ACCEI ERASED DOCVMENT DISTBVTION SYSTEM REGULA~AY INFORMATION DISTRIBUTI~SYSTEM (RIDS)ACCESSION NBR:9303020089 DOC.DATE: 93/01/20 NOTARIZED:
NO DOCKET FACIL:50-397 WPPSS Nuclear Project,-Unit 2, Washington Public Powe 05000397 AUTH.NAME AUTHOR AFFILIATION MACKAMAN,C.D.
Washington Public Power Supply System BAKER,J.W.
Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION
SUBJECT:
LER 93-002-00:on 930121,low RPV level reactor scram initiated by RPS in response'to actual.low water level condition.
Caused by high thrust bearing wear trip of RFW Pump 1A turbine.Pressure reduction commenced.W/930222 ltr.DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR g ENCL g SIZE: F TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt', etc.NOTES: RECIPIENT ID CODE/NAME PD5 LA CLIFFORD,J INTERNAL: ACNW AEOD/DOA AEOD/ROAB/DSP NRR/DE/EMEB NRR/DRCH/HHFBHE NRR/DRCH/HOLB NRR/DRSS/PRPB NRR/DSSA/SRXB RES/DSIR/EIB EXTERNAL: EGSG BRYCE,J.H NRC PDR NSIC POOREiW.COPIES LTTR ENCL 1 1 1 1 2 2 1 1 2 2 1 1 1 1 1 1 2 2 1 1 1 1 2 2 1 1 1 1 RECIPIENT ID CODE/NAME PD5 PD ACRS AEOD/DSP/TPAB NRR/DE/EELB NRR/DORS/OEAB NRR/DRCH/HICB NRR/DRIL/RPEB N QDSS SPLB RB~LE 02 RSN5 ILE 01 L ST LOBBY WARD NSIC MURPHY,G.A NUDOCS FULL TXT COPIES LTTR ENCL 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE!CONTACI'HE DOCUMENT CONTROL DESK, ROOM PI-37 (EXT.504-2065)TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 32 ENCL 32 WASHINGTON PUBLIC;POWER SUPPLY SYSTEM P.O.Box 96B~3000 George Washington 1Vay~Richland, 1Vashington 99352 February 22, 1993 G02-93-039 Docket No.50-397 Document Control Desk U.S.Nuclear Regulatory Commission Washington, D.C.20555 s f
SUBJECT:
NUCLEAR PLANT WNP-2, OPERATING LICENSE NPF-21 LICENSEE EVENT REPORT NO.93-002 Transmitted herewith is Licensee Event Report No.93-002 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.
Sincerely,/J.W.Baker WNP-2 Plant Manager (Mail Drop 927M)JWB/CDM/nw 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)I re<1"1 1.',Q 9303020089
'P30i20 PDR ADOCK 050003'P7 S PDR ACILITY NAHE (I)LICENSEE EV REPORT (LER)Washin ton Nuclear Plant-Unit 2 DOCKET NUMB R ()PAGE (3)0 5 0 0 0 3 9 7 I OF 7 ITLE (4)REACTOR SCRAM DUE TO LOW RPV LEVEL AS A RESULT OF LOSS OF REACTOR FEEDWATER PUMP CAUSED BY AN INADVERTENT ACTUATION OF THE DELUGE SYSTEM EVENT DATE 5)LER NUHBER 6)REPORT DATE 7 OTHER FACILITIES INVOLVED (8)MONTH 0 I DAY YEAR 2 1 9 3 YEAR 9 3 SEQUENTIAL NUHBER 0 0 2 EVI SION UMBER MONTH DAY YEAR 0 0 0 1 2 0 9 3 FACILITY NAHES CKE NUMB 5 0 0 0 5 0 0 0 RS(S)P ERAT ING ODE (9)HIS REPORT IS SUBHITTEO PURSUANT TO THE REQUIREMENTS OF 10 CFR 5: (Check one or more of the following)
(11)I ONER LEVEL (10)0.402(b)0.405(a)(1)(i) 20.405(a)(1)(ii) 20.405(a)(1)(iii) 20.405(a)(1)(iv) 20.405(a)(1)(v) 20.405(C)50.36(c)(1) 50.36(c)(2) 50.73(a)(2)(i) 50.73(a)(2)(ii) 50.73(a)(2)(iii)
X 50.73(a)(2)(iv) 50.73(a)(2)(v) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(x) 77.71(b)73.73(c)THER (Specify in Abstract elow and in Text, NRC Form 366A)HAHE LICENSEE CONTACT FOR THIS LER 12 C.D.Mackaman, Compliance Engineer TELEPHOHE NUMBER REA CODE 5 0 9 7 7-4 4 5 1 COMPLETE OHE LIHE FOR EACH COMPONENT FAILURE DESCRIBED IH THIS REPORT (13)CAUSE S'STEM COMPONENT MAHUFACTURER EPORTABLE 0 HPRDS CAUSE SYSTEM COMPOHEHT MANUFACTURER REPORTABLE TO HPRDS SUPPLEMENTAL REPORT EXPECTED (14)YES (If yes, complete EXPECTED SUBHISSIOH DATE)NO vaacv na}EXPECTED SUBMISSIOH MONTH DAY YEAR ATE (15)On January 21, 1993, at 0948 hours0.011 days <br />0.263 hours <br />0.00157 weeks <br />3.60714e-4 months <br />, a low Reactor Pressure Vessel (RPV)level reactor scram was initiated by the Reactor Protection System (RPS)in response to an actual low water level condition.
The low RPV level was caused by a"high thrust bearing wear" trip of the Reactor Feedwater (RFW)Pump 1A turbine.The trip signal was generated as a result of wetted vibration sensing circuitry caused by an inadvertent actuation of the RFW Pump Room"A" fire protection deluge system.The remaining RFW pump was unable to supply enough water to maintain RPV level above the reactor scram setpoint.This was due to the failure of the Reactor Recirculation (RRC)Pump Flow Control Valves to automatically reposition (runback)to reduce reactor power and steam flow to within the capacity of one RFW pump.The immediate corrective action was prompt response by the Plant Operators to bring the plant to a safe shutdown condition in accordance with approved Plant Operating Procedures.
Three root causes for this event have been identified:
1.Personnel/work practices error causing the inadvertent actuation of the RFW Pump Room"A" fire protection deluge.
LICENSEE EVENT REPOR ER)TEXT CONTINUATION
~AGILITY KAME (1)Washington Nuclear Plant-Unit 2 DOCKET NUMBER (2)0 5 0 0 0 3 9 7 LER NUMBER (8)ear umber ev.No.AGE (3)3 02 0 2 f 7 ITLE (4)REACTOR SCRAM DUE TO LOW RPV LEVEL AS A RESULT OF LOSS OF REACTOR FEEDWATER PUMP CAUSED BY AN INADVERTENT ACTUATION OF THE DELUGE SYSTEM 2.Management methods/work organization planning error in that there was no method in the painting pre-job planning process to provide the painters with precautionary information relating to sensitive equipment.
3.Plant equipment/design configuration and analysis error in that the RFW Pump Room fire protection manual discharge stations are not well suited for an industrial machinery environment.
'his event posed no threat to the safety of the public or plant personnel.
P~ICh i Power Level-100%Plant Mode-1 (Power)Event Descri ion On January 21, 1993 at 0945 hours0.0109 days <br />0.263 hours <br />0.00156 weeks <br />3.595725e-4 months <br />, the Plant Control Room Operators received a Reactor Feedwater Pump (RFW)Pump Room"A" fire protection deluge system actuation annunciator and several alarms relevant to'the auto start of the fire pumps.At 0947 hours0.011 days <br />0.263 hours <br />0.00157 weeks <br />3.603335e-4 months <br />, the Control Room Operators received the RFW Pump 1A and 1B turbine vibration trouble annunciators, followed by the RFW Pump 1A and 1B turbine high thrust bearing wear annunciators.
At 09:47:57 hours, the RFW Pump 1A turbine tripped, and immediately, the Reactor Pressure Vessel (RPV)level decreased from+35 inches to+30 inches (Level 4).At which point, the Reactor Recirculation (RRC)System initiated an automatic RRC Flow Control Valve (FCV)Runback as designed.The"B" FCV repositioned to 26%open and the"A" FCV repositioned to 82%open.The setpoint for both valves was 20%open.The failure of the"A" and"B" Flow Control Valves to fully reposition caused reactor power and steam flow to remain significantly above the capacity of one operating RFW pump.As a result, the remaining RFW pump (1B)was unable to supply enough water to maintain RPV level above the reactor scram setpoint, and the RPS initiated an automatic Low RPV Level 3 (+13 inches)Reactor Scram at 09:48:20 hours.Following the reactor scram, RPV level continued to decrease due to the normally encountered post scram level transient.
The lowest RPV level reached was-19.4 inches at 09:48:55 hours.The main turbine tripped at 09:49:28 hours in response to the reactor scram, and immediately, RPV level began to rapidly recover due to the reduced steam flow and the continuous RFW Pump 1B feed supply.The RFW pump turbine controls could not respond quickly enough to prevent a RPV high level overshoot, and at 09:49:35 hours, the RFW Pump 1B turbine tripped on a RPV Level 8 (+54 inches)trip signal.The highest RPV level reached during the transient was+63 inches at 09:49:40 hours, All Control Rods fully inserted and no Safety Relief Valves were actuated during this event.
LICENSEE EVENT REPOR ER)TEXT CONTINUATION AGILITY NAHE (1)Washington Nuclear Plant-Unit 2 OOCKET NUHBER (2)0 5 0 0 0 3 9 7 LER NUHBER (8)ear umber ev.No.3 002 00 AGE (3)3 F 7 ITLE (4)REACTOR SCRAM DUE TO LOW RPV LEVEL AS A RESULT OF LOSS OF REACTOR FEEDWATER PUMP CAUSED BY AN INADVERTENT ACTUATION OF THE DELUGE SYSTEM Imm i In accordance with 10CFR50.72(b)(2)(ii), this event was reported to the NRC Operations Center via the Emergency, Notification System at 1034 on January 21, 1993, as an unplanned automatic actuation of the Reactor Protection System (RPS).'r iv A i n The immediate corrective action by the Plant Operators was to promptly enter Emergency Operating Procedure (EOP)5.1.1, Reactor Pressure Vessel Power, Level, and Pressure Control, and initiate a Manual Scram (four seconds after the automatic low RPV level scram).Pressure reduction was commenced at approximately 8 psi/min in anticipation of utilizing the Condensate Booster Pumps for level control.Reactor Core Isolation Cooling (RCIC)was manually initiated to maintain RPV level in the normal range, and the plarit was brought to a safe shutdown condition in accordance with Reactor Scram Recovery Procedure PPM 3.3.1.Further Eval ation n orrec ive Ac i n Further Evalu ion This event is being reported as an event that resulted in automatic actuation of the Reactor Protection System (RPS)in accordance with the requirements of 10CFR50.73(a)(2)(iv).
There were no structures, components, or systems inoperable prior to this event that contributed to the event.3.The initial post scram investigation found that Supply System painters outside RFW Pump Room"A" had accidentally actuated a fire protection manual discharge station while preparing the area for painting.The discharge station actuation initiated the fire protection deluge system, which sprayed water on the RFW Pump turbine vibration monitoring cabinet.Water entered the cabinet causing the sensing circuitry to generate spurious RFW Pump turbine vibration trouble and high thrust bearing wear alarms, and finally, the high thrust bearing wear trip signal to the RFW Pump 1A turbine.4 Troubleshooting of the RRC Flow Control Valves found that a"Servo Error" trip of both Hydraulic Pump Units for the valves caused the incomplete automatic valve runbacks.The"Servo Error" trip signals were generated as a result of slow valve responses and reduced velocity feedback signal gains.The cumulative negative effect being enough to prevent the feedback signals from properly tracking the velocity demand signals.When the signal differentials reached their setpoints, indicating valve position control failures,"Servo Error" signals were generated to shutdown the Hydraulic Pump Units.
LICENSEE EVENT REPOR ER)TEXT CONTINUATION AGILITY NAHE (1)Washington Nuclear Plant-Unit 2 DOCKET NUHBER (2)0 5 0 0 0 3 9 7 LER NUHBER (8)ear umber ev.No.AGE (3)3 002 00 4 F 7 ITLE (4)REACTOR SCRAM DUE TO LOW RPV LEVEL AS A RESULT OF LOSS OF REACTOR.FEEDWATER PUMP CAUSED BY AN INADVERTENT ACTUATION OF THE DELUGE SYSTEM foot (~ye Three root causes for this event have been identified:
Personnel/work practices error causing the inadvertent actuation of the RFW Pump Room"A" fire protection deluge system via the local manual discharge station.This initial root cause is considered by Supply System Management to be the primary cause of the chain of events that ultimately led to the reactor scram.2.Management methods/work organization planning error in that there was no method in the painting pre-job planning process to identify sensitive system specific equipment and provide the painters with precautionary information relating to the equipment.
3.Plant equipment/design configuration and analysis error in that the RFW Pump Room fire protection manual discharge stations are of an older single action pull type not well suited for an industrial machinery environment.
This type of pull station is designed for ease of manipulation (ie., schools, public buildings, etc.), making it vulnerable to inadv'ertent actuation when located where incidental contact is likely during machinery maintenance and inspections.
WNP-2 has experienced inadvertent actuations of similar (alarm only)pull stations in the past.Two contributing causes for this event have been identified:
The failure of system design reviews and analyses to anticipate the negative effects of component interactions following system design changes, modifications and maintenance, The combined negative effects of the component interactions caused the"Servo Error" trip of both Hydraulic Pump Units for the RRC Flow Control Valves, which resulted in incomplete automatic valve runbacks.The design changes, modifications and maintenance to the Flow Control Valves, Hydraulic Power Units, and the associated electronics in 1989 and 1990 resulted in slowed valve responses and reduced velocity feedback signal gains.The affected components were satisfactorily retested in accordance with Maintenance Work Request (hDVR)post maintenance test requirements.
However, the Flow Control Valve Runback system was not reviewed for the cumulative effects of the component work, or functionally tested as a system, since full runback conditions could not be simulated during plant shutdown.2.The inability of the RFW pump vibration monitoring cabinet to protect the sensing circuitry from the fire protection deluge system water spray.Water entering the cabinet caused the sensing circuitry to generate a spurious high thrust bearing'wear trip signal to the RFW Pump 1A turbine.
LICENSEE EVENT REPOR ER)TEXT CONTINUATION ACILiTY NAHE (1)Washington Nuclear Plant-Unit 2 DOCKET NUHBER (2)0 5 0 0 0 3 9 7 LER NUHBER (8)ear umber ev.No.3 02 0 AGE (3)5 F 7 ITLE (4)REACTOR SCRAM DUE TO LOW RPV LEVEL AS A RESULT OF LOSS OF REACTOR FEEDWATER PUMP CAUSED BY AN INADVERTENT ACTUATION OF THE DELUGE SYSTEM Further Corr iv Ac i n Disciplinary action, including time off without pay, was taken against the painter who actuated the fire protection manual discharge station, his work partner and their supervisor.
Completed February 5, 1993.2.Conduct a"time out" session with the painters to re-emphasize the importance of constant vigilance when working around plant equipment.
Completed January 25, 1993.3.The RFW Pump vibration monitoring cabinet was inspected, dried out, cleaned, refurbished and tested with assistance from a manufacturer's representative called in for an independent system assessment.
MWR AP2112 completed January 25, 1993.4.Proper operation of the RFW pump a'nd turbine thrust bearing wear sensing circuits was verified.MWR AP2113 completed January 26, 1993.5.Velocity signal conditioning modules are located in the output circuits of the Flow Control Valve motion sensing Linear Variable Transformers to provide a velocity feedback signal output, The modules were readjusted and tested to produce the proper velocity feedback signal gains to track the velocity demand signals.MWR AP2142 completed January 29, 1993.NOTE: Supply System Management elected not'o perform a runback test of the RRC Flow Control Valves since the test must be performed at full reactor power and could subject the plant to an undesirable transient.
The runback control system is a commercial feature designed to enhance operational reliability, and not an engineered safety feature.Therefore, it is management's view that it would not be in the best interest of the plant to test a non-safety feature by potentially challenging safety features.However, the Supply System has the capability to evaluate system performance following future runback events.Furthermore, there was a significant amount of knowledge and information gained during the troubleshooting of the runback control system for this event.As a result, there is reasonable assurance that the post maintenance testing performed following completion of Corrective Action 5 (above)was adequate to ensure proper operation of the runback system.6.Design, fabricate and install a temporary water shield for the RFW Pump vibration monitoring cabinet.MWR AP2167 completed January 26, 1993.7.Procure and install permanent protective covers for the fire protection deluge system manual discharge stations located in RFW Pump, Rooms A and B.This action to be completed by June 15, 1993.
'ICENSEE EVENT REPOR ER)-TEXT CONTINUATION AGILITY NAME (1)Washington Nuclear Plant-Unit 2 OOCKET NUMBER (2)if LER NUMBER (8)ear'(umber ev.No.3 002 0 AGE (3)" 6 F 7 ITLE (4)REACTOR SCRAM DUE TO LOW RPV LEVEL AS A RESULT OF LOSS OF REACTOR FEEDWATER PUMP CAUSED BY AN INADVERTENT ACTUATION OF THE DELUGE SYSTEM 8.Perform an evaluation to identify other)systems and components important to plant operational reliability which are vulnerable to failure due to fire protection deluge system actuation.
Provide recommendations for corrective action.This action to be completed by March 15, 1993.'Review the manual discharge stations loc'ated within the plant.Evaluate each station for proper mounting location and provide recommendations for either installation of permanent protective covers, or replacement with the'new'ual action type station.This action to be completed by March 15, 1993.10.Replace the temporary water shield for the RFW pump vibration monitoring cabinet with a permanent shield or vendor supplied weatherproof panels.This action to be completed by July 31, 1993.12.Evaluate current administrative controls and work practices for painting inside the power block, This action to be completed by April 15, 1993.ii'lant Procedure PPM 8.3.120, Recirculation Flow Control Valve-Alignment/Calibration, will be revised to include control system'alibration and testing information gained during troubleshooting for this event.This action to be completed by, April 15, 1993.S~ii l1 The Plant Operators reacted correctly in conjunction, with installed plant safety systems to promptly bring the plant to a safe shutdown condition.
Although an actual RPV low level condition did exist for a short period, with vessel level decreasing to,-19.4 inches, the transient was well within the bounds of WNP-2 safety analysis.A reactor scram was the appropriate plant response to an incomplete runback of the RRC Flow Control Valves during the loss of an.RFW pump.In responding to the reactor scram, the plant satisfactorily demonstrated its ability to maintain adequate RPV water level under the resulting transient conditions.
Accordingly, this event posed no threat to the safety of the public or plant personnel.
LICENSEE EVENT REPOR ER)TEKl CONTINUATION ACILITY NAHE (1)Washington Nuclear Plant-Unit 2 DOCKET NUHBER (2)0 5 0 0 0 3 9 7 fear LER NUHBER (8)umber ev.No.3 02 0 AGE (3)7 F 7 1TLE (4)REACTOR SCRAM DUE TO LOW RPV LEVEL AS A RESULT OF LOSS OF REACTOR FEEDWATER PUMP CAUSED BY AN INADVERTENT ACTUATION OF'THE DELUGE SYSTEM Similar Even LER 89-031,"Reactor Scram Due to Low RPV Level as a Result of Loss of Reactor Feedwater Pump During Lube Oil Pump Surveillance Testing-Cause Indeterminate".
The root cause of this event was indeterminate.
However, a contributing factor for the reactor scram was identified as the inappropriate RRC Flow Control Valve Runback setpoint of 30%open.This setpoint maintained reactor power and steam flow above the capability of one RFW pump, causing RPV level to decrease, resulting in a Low, RPV Level 3 reactor scram.The corrective action was to reduce the valve runback setpoint to 20%open.Since no Hydraulic Pump Units tripped, and runback appeared to function properly with the previous setpoint during the event, and during subsequent testing with the new setpoint, no further corrective action was identified.
Apparently, the cumulative effects of later system work caused the current runback control system failure.EIIS Inf rm ti n Text Reference f$g~tem~om onen Reactor Pressure Vessel Reactor Recirculation System Reactor Protection System Reactor Feedwater Pump Turbine 1A Reactor Feedwater Pump Turbine 1B Reactor Feedwater Turbine I&C System Reactor Feedwater Control System Reactor Recirculation Flow Control Valve Fire Protection System (Water)AC AD JC SJ SJ JK JB AD KP RPV FU TRB TRB CAP FCV