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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 DIST UTION SYSTEM REGULAT~ INFORMATION DISTRIBUTION STEM (RIDS)
'CCESSION"NBR:9306030259 DOC.DATE: 93/05/28 NOTARIZED: NO DOCKET j FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe AUTH. NAME AUTHOR AFFILIATION 05000397 LEWIS,K.B. Washington Public Power Supply System PARRISH,J.V. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION
SUBJECT:
LER 93-018-00:on 930428,discovered design condition that could have impacted plants ability to mitigate accident D conditions. Caused by less than adequate change mgt.Abnormal operating procedures will be revised.W/930528 ltr.
DISTRIBUTION CODE: ZE22T COPIES RECEIVED:LTR TITLE: 50.73/50.9 Licensee Event Report V ENCL SIZE:
(LER),incident Rpt, etc.
NOTES:
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D PDV LA 1 1 PDV PD 1 1 CLIFFORD,J 1 1 INTERNAL: ACNW 2 ACRS 2 2 AEOD/DOA 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 NRR/DORS/OEAB 1 1 NRR/DRCH/HHFB 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 NRR/DRIL/RPEB 1 1 NRR/DRSS/PRPB 2 RR DDSA/SPLB 1 1 NRR/DSSA/SRXB 1 REG=F~~ 02 1 1 RES/DSIR/EZB 1 RGN5 FILE 01 1 1 EXTERNAL: EG&G BRYCE,J.H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POOREgW. 1 1 NUDOCS FULL TXT 1 1 D
D D
NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTEI CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR 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 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 May 28, 1993 G02-93-129 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.93-018 Transmitted herewith is Licensee Event Report No.93-018 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, pe/Z J. V. Parrish (Mail Drop 1023)
Assistant Managing Director, Operations JVP/KBL/jd Enclosure CC: Mr. B. H. Faulkenberry, 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) 02007i.
9306030259 930528 PDR ADOCK 05000397 S PDR
LICENSEE EVE EPORT (LER)
AGILITY NAME (1) DOCKET NUMB R ( ) PAGE (3)
Washin ton Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 I OF 7 ITLE (4)
SPENT FUEL POOL MAKEUP NOT ADEQUATE TO MITIGATEACCIDENT CONDITIONS EVENT DATE (5) LER NUMBER 6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)
MONTH DAY YEAR YEAR SEQUENTIAL EVISION MONTH DAY YEAR FACILITY NAMES CKE UMB RS(S)
NUMBER NUMBER 0 0 0 0 4 2 8 9 3 9 3 0 1 8 0 0 0 5 2 8 9 3 000 P ERAT ING HIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 5: (Check one or more of the following) (11)
ODE (9) 1 OWER LEVEL 20.402(b) 0.405(C) 50.73(a)(2)(iv) 77.71(b) 20.405(a)(1)(i) 0.36(c)(1) 50.73(a)(2)(v) 73.73(c) 0 9 3 0.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) THER (Specify in Abstract 0.405(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)(8) Form 366A) 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)
LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUHBER Kurt B. Lewis, Licensing Engineer REA CODE 5 0 9 7 7 - 4 1 4 5 COMPLETE ONE LINE FOR EACH COMPONEN'T FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE SYSTEM COMPDHEHT HAHUFACTURER EPDRTABLE ::;g'jij;; CAUSE SYSTEM COHPOHENT MANUFACTURER REPORTABLE 0 HPRDS TO HPRDS SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED SUBMISSIOH MOH'TH DAY YEAR ATE (15)
YES (lf yes, comptete EXPECTED SUBMISSIOH DATE) HO TRACT ne)
On April 28, 1993, the WNP-2 Management Review Committee (MRC) concluded its review of a problem associated with the Fuel Pool Cooling (FPC) system and decided it was a reportable event.
Previously, on April 23, 1993, a plant support engineer discovered a design condition that could have impacted the plant's ability to mitigate the consequences of an accident. In the event of a Loss Of Coolant Accident (LOCA), the Service Water system (SW) must be able to supply emergency makeup water to the Spent Fuel Pool (SFP). Makeup is normally supplied by the Condensate Storage and Transfer system, a non-safety-related system. Without makeup, water in the pool would have continued to evaporate until the Fuel Pool Cooling system (FPC) pump tripped. This would have resulted in eventual fuel pool boiling, Vapors generated by the elevated Spent Fuel Pool temperature would have condensed, flowed to the bottom of the Reactor building, and caused a loss of the Emergency Core Cooling (ECCS) pumps due to flooding. Service water would not have been immediately available because manual isolation valves SW-V-75AA and BB are presently closed, and access to these valves was analyzed to be restricted during post-LOCA conditions.
Immediate corrective action included performing an analysis to verify the feasibility of continued, safe operation until the next refueling outage, which began on April 30, 1993.
Further corrective actions included performing engineering calculations and revising plant documents to justify continued closure of manual isolation valves SW-V-75AA and BB during normal plant operations.
LICENSEE EVENT REPORT R)
TEXT CONTINUATION AGILITY NAHE (I) OOCKET NUHBER (2) LER NUHBER (8) AGE (3)
Year umber ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 3 018 00 2 OF 7 TITLE (4)
SPENT FUEL POOL MAKEUP NOT ADE(UATE TO MITIGATE ACCIDENT CONDITIONS The root cause for this event was less than adequate change management.
This event posed minimal risk to safe plant operation.
Ch i Power Level - 93%
E~
Plant Mode - 1 (Power)
On April 28, 1993, the WNP-2 Management Review Committee (MRC) concluded its review of a problem associated with the Fuel Pool Cooling (FPC) system and decided it was a reportable event. Previously, on April 23, 1993, a plant support engineer discovered a design condition that could have impacted the plant's ability to mitigate the consequences of an accident. During accident conditions, the SW system is designed to remote-manually supply redundant, emergency makeup to the Spent Fuel Pool from SW loops "A" and/or "B". Each redundant makeup line includes a pair of series-installed isolation valves. The first valve in each pair is a locally operated, manual isolation valve [SW-V-75 AA(BB)]. Both manual valves are located on the 522 elevation of the Reactor Building. The second valve in each pair is a remote-manual, motor operated isolation valve [SW-V-75A(B)]. Remote-manual operation is from the main control room.
Currently, all of these valves are normally closed. This is in conflict with the Final Safety Analysis Report (FSAR) which specifies actuation of the SW makeup by no other operator action than remote-manual actuation of the motor operated isolation valves.
During his analysis of the problem, the engineer determined that leaving the manual isolation valves normally closed could preclude a control room operator's ability to remote-manually supply emergency SW makeup to the Spent Fuel pool during a Loss Of Coolant Accident (LOCA). Use of the manual valves could be precluded, because the LOCA could generate sufficient radiation fields in the Reactor Building to restrict accessing the manual valves prior to unacceptably high Spent Fuel Pool temperatures being reached.
This inability to supply the fuel pool with makeup could result in pool boiling and the resultant vapor could condense and end up in the ECCS pump rooms. Since the Reactor Building sump pumps are not safety related, no credit can be taken for them during an accident. Thus, the condensed vapor could ultimately flood the ECCS pump rooms and render the ECCS pumps inoperable. Additionally, the operability of the Standby Gas Treatment system (SGT) cannot be assured at Spent Fuel Pool temperatures in excess of 155'F, as no analysis exists for this condition.
LICENSEE EVENT REPORT R)
TEXT CONTINUATION AGILITY NAME (I) OOCKET NUMBER (2) LER NUMBER (8) AGE (3)
Year umber ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 3 0 I B 00 3 OF 7 TITLE (4)
SPENT FUEL POOL MAKEUP NOT ADEQUATE TO MITIGATE ACCIDENT CONDITIONS mmedi te rrective A i n Immediate corrective action included performing an analysis to verify the feasibility of continued, safe operation. Results of the analysis, based principally on currently low fuel pool temperatures and heat loads, showed that continued operation at power was feasible up to the R8 refueling outage, which began on April 30, 1993.
F rther Ev I ion n rrec ive Ac ion Further Evaluation
- 1. On April 28, 1993 at 1019 hours0.0118 days <br />0.283 hours <br />0.00168 weeks <br />3.877295e-4 months <br />, this event was reported to the NRC as a four-hour reportable event under 10CFR50.72(b)(2)(iii)(D), as "Any event or condition that alone could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident".
- 2. This event is also being reported under 10CFR50,73(a)(2)(v)(D), as "Any event ... that alone could have prevented ... the safety function of ... systems ... needed to mitigate the consequences of an accident".
- 3. There were no structures, components, or systems inoperable prior to this event that contributed to this event.
- 4. Prior to 1979, the original FPC system design basis allowed Spent Fuel Pool boiling during a severe seismic event and provided for safety grade makeup from the SW system. In 1979, the NRC informed the Supply System that boiling was not acceptable and offered several alternative designs.
The Supply System subsequently redesigned the FPC system to prevent pool boiling and to ensure that adequate water level is maintained during a seismic event or major plant disturbance. Among the design criteria was the stipulation that "remote-manual, redundant SW system makeup to the fuel pool" be provided (as stated by the FSAR, section 9.1.3.1).
- 5. To satisfy remote-manual makeup requirements, original design plans requested motors be placed on existing, locally operated, SW-to-SFP manual isolation valves. However, economics, physical constraints, and testing requirements prevented this design from being completed.
- 6. Rather, Plant Engineering Directive (PED) 215-M-C342, written on August 5, 1982, retagged the manual isolation valves as SW-V-75AA and 75BB and left them in place. Downstream of these valves, the PED directed installation of corresponding remote-manual, motor operated isolation valves SW-V-75A and 75B.
LICENSEE EVENT REPORT )
TEXT CONTINUATION FACiLiTY NAME (1) DOCKET NUMBER (2) LER NUMBER (B) PAGE (3)
Year Number ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 3 018 00 4 OF 7 ITLE (4)
SPENT FUEL POOL HAKEUP NOT ADEQUATE TO HITIGATE ACCIDENT CONDITIONS
- 7. Per PED 215-M-C342, no change to the FSAR was anticipated based on leaving the manual valves installed in the system. However, when the final valve configuration was redrawn on SW flow diagrams M524 sheets 1 & 2 (REV 35, November 5, 1982), valves SW-V-75AA and BB were incorrectly depicted as normally closed. The manual isolation valves should have been redrawn as normally open (NO), the position required to support remote-manual operation.
- 8. Additionally, revision one of the SW operating procedure, issued on August 30, 1983, duplicated this error by aligning these valves as normally closed. Subsequent revisions to this procedure carried this error.
- 9. On October 31, 1991, Problem Evaluation Request (PER) 291-899 identified this error in valve alignment. The PER stated that the "commitment for remote-manual operation cannot be met".
The MRC incorrectly identified the limiting condition for continued FPC system operation without makeup as the rate of pool evaporation, without considering the effect based upon the FPC Skimmer Surge tank low-water-level trip of the FPC pumps. The MRC recommended revising the FSAR to reflect all SW-to SFP isolation valves as normally closed and recommended revising engineering calculations to support manual operator action to open the manual isolation valves.
- 10. To support the MRC's recommendation to revise engineering calculations, engineering calculated evaporative water losses from the Spent Fuel Pool during a loss of makeup. The calculation conservatively assumed a pool temperature of 155'F and a full offload after cycle 12. However, the calculation incorrectly assumed that one of the two FPC system pumps continued to circulate water from the Spent Fuel Pool, through FPC system heat exchangers, and then back to the Spent Fuel Pool during the loss of makeup. This assumption was incorrect, because the pumps trip on associated low water level in the FPC Skimmer Surge Tanks. Thus, the calculation incorrectly showed that it would take approximately 128 days for the pool's water level to decrease to the top of the fuel. The calculated radiation levels in the Reactor Building at this time would be low enough to allow'accessing manual isolation valves SW-V-75AA and BB, Based on this information, a low-priority Request For Technical Services (RFTS) was written to revise the FSAR to reflect all SW-to-SFP isolation valves as NC.
On April 23, 1993, a plant support engineer responded to the RFTS by preparing the necessary revisions to the FSAR. The engineer discovered the error in the 1991 engineering calculation while he was completing a related 10CFR50.59 analysis. The engineer immediately wrote a PER documenting the problem. The PER originally requested opening the manual isolation valves, but this request was changed to read "evaluate for other options". Further evaluation was requested, because plant personnel wanted to maintain two barriers between a radioactive system and the environment.
LICENSEE EVENT REPORT ( )
TEXT CONTINUATION AGILITY NAME (I) OOCKET NUMBER (2) LER NUMBER (8) PAGE (3)
Year Number ev. No.
Washington Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 3 018 00 5 OF 7 ITLE (4)
SPENT FUEL POOL MAKEUP NOT ADEQUATE TO MITIGATE ACCIDENT CONDITIONS
- 12. Further evaluation was pursued and a Basis For Continued Operation (BCO) was written in the interim to justify continued plant operation with the manual isolation valves left closed. Further evaluation was pursued, because plant personnel wanted to maintain double isolation of the SW-to-SFP emergency makeup lines, Personnel believed this to be desirable, because double isolation provided additional assurance that the fuel pool water does not leak into the Service Water System when the Service Water System is not operating.
- 13. The BCO, based on low fuel pool temperatures and heat loads, showed that continued operation at power was feasible up to the R8 refueling outage, which began on April 30, 1993. Details of the BCO follow:
ao The Spent Fuel Pool temperature was assumed to be 155'F during accident analysis (a condition in which evaporation in the Reactor Building has been analyzed with no challenge to the Standby Gas Treatment system); actual pool temperature was well below this value.
Accident analysis requires the assumption that the maximum heat load exists in the pool; the actual heat load was low. Recent data from an FPC system outage showed that the Spent Fuel Pool would heat up at 6'F per day. If the Spent Fuel Pool was maintained less than 90'F during reactor operation, even with the FPC Skimmer Surge Tanks at their minimum water level of 26 inches above the FPC system pump trip, the FPC pumps would operate for approximately nine hours, assuming an evaporation rate at a pool temperature of 155'F.
After the FPC pumps trip on low Skimmer Surge Tank water level, it would take the relatively low heat load in the pool eleven days to increase the pool's temperature to 155'F.
Evaporative losses during this eleven day period would reduce pool water level less than two feet.
- b. Reactor Building radiation levels following a LOCA are based on worst case conditions.
Even under these worst case conditions, an operator donned in Self Contained Breathing Apparatus (SCBA) could open both of the manual isolation valves in less than ten minutes.
Performing this emergency operation would result in the operator receiving a whole body dose of less than five Rem, the maximum dose allowed by regulatory guides applicable to these manual, operator- action requirements. The entry would have to be made eleven days following the LOCA.
C. As long as the Spent Fuel Pool is maintained lower than 90'F and the current heat load is maintained, the plant support engineer justified leaving the manual isolation valves closed.
LICENSEE EVENT REPORT ( R)
TEXT CONTINUATION AGILITY NAHE (i) 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 3 018 6 F 7 ITLE (4)
SPENT FUEL POOL MAKEUP NOT ADEQUATE TO MITIGATE ACCIDENT CONDITIONS Roo~
@i'he root cause for maintaining Service Water valves SW-V-75AA and BB normally closed was a less than adequate review of the associated 1982 design change specifications against related FSAR requirements for "remote-manual, redundant SW system makeup to the fuel pool". Therefore, this 1982 event receives an INPO root cause classification of Less Than Adequate (LTA) Change Management. A contributing cause for this event was procedurally specifying Service Water valves SW-V-75AA and BB as normally closed, rather than open. This contributing cause receives an INPO classification of Technical Inaccuracies in Written Procedures.
u her rrec ive Action The process for writing and implementing design change packages has improved since the Plant Engineering Directive process that was used to install motor operated valves SW-V-75A and B. For example, the present 10CFR50.59 process and the capability to word search the FSAR has greatly enhanced a person's ability to compare design changes against the FSAR. Additionally, procedural support organizations are now in place to assist in the development or revision of plant procedures.
With respect to the Change Management issue, no further corrective action is recommended.
- 2. On May 13, 1993, operator actions were performed to determine the Reactor Building stay time by entering the building and simulating opening the manual valves and recording the time required.
Stay time was determined to be two minutes, thirty seconds.
- 3. On May 24, 1993, engineering analysis verified that manual isolation valves SW-V-75AA and BB can be opened during post-accident conditions to prevent fuel pool heatup and boiling. From the analysis, it was concluded that the manual isolation valves can be left normally closed, and that if these valves were opened in no more than three minutes during LOCA conditions, an operator would receive a whole body dose of 4.85 REM. Because the probability for a LOCA to actually occur is low (2.17 x 104 events/year), and since a LOCA concurrent with a loss of fuel pool makeup is extremely low, the Supply System decided to use the results of this engineering analysis to justify continued closure of manual isolation valves SW-V-75AA & BB.
4 An FSAR change notice will be prepared to include discussion of local-manual, as well as remote-manual operating requirements of the SW-to-SFP emergency makeup water crosstie during a LOCA.
This will be completed by September 31, 1993.
- 5. Instrument Master Data Sheets will be revised per engineering calculation E/I-02-92-1042 to specify a new, lower setpoint for the fuel pool high temperature alarm. This will be completed prior to R8 restart on or about June 15, 1993.
LICENSEE EVENT REPORT ~ )
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 7 3 018 00 7 OF 7 ITLE (4)
SPENT FUEL POOL MAKEUP NOT ADEQUATE TO MITIGATE ACCIDENT CONDITIONS
- 6. Annunciator response procedures 4.626.FPC1 1-2 (4.627FPC2 1-2) "Fuel Pool Temperature High" will be revised to specify a new, lower fuel pool high temperature alarm setpoint and provide the required actions to be taken upon receipt of the alarm. This will be completed prior to R8 restart on or about June 15, 1993.
- 7. Abnormal operating procedure 4.8.5.1 "Loss of Fuel Pool Cooling" will be revised to include instructions for use of SW-to-SFP emergency makeup during accident conditions. This will be completed prior to R8 restart on or about June 15, 1993.
Safe N The FSAR requires remote-manual, redundant SW emergency makeup to the Spent Fuel Pool. Because related manual isolation valves were left closed, the ability to supply this emergency makeup during accident conditions was challenged. However, due to the low probability for a LOCA and simultaneous loss of the normal source of makeup to the Spent Fuel Pool, this event posed minimal risk to safe plant operation.
imilar Events There are no similar LER events involving Spent Fuel Pool boiling and loss of accident mitigation capability.
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Qi~mo~nen Fuel Pool Cooling System (FPC) OA Service Water System (SW) BI SW Manual Isolation Valves SW-V-75AA(BB) BI Condensate Storage & Transfer KA SW Motor Operated Valves SW-V-75A(B) BI FPC Skimmer Surge Tank SKR Standby Gas Treatment System (SGT) BH FPC Pump P FPC Heat Exchanger HX