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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML18017A9181999-10-0808 October 1999 LER 99-008-00:on 991008,CR Emergency Filtration Sys Tech Specs Occurred.Caused by Site Personnel Failed to Recognize That Blocking Open CR Emergency Filtration Sys.Procedures Revised.With 991008 Ltr ML18017A8671999-09-10010 September 1999 LER 99-007-00:on 990811,determined That Cvis ARMs High Alarm Setpoints Were Not within TS Limit.Caused by Not Having Procedure to Verify If Cvis ARM High Alarm Setpoints Were within TS Requirements.Revised Procedures.With 990910 Ltr ML18016B0481999-08-0404 August 1999 LER 99-006-01:on 981124,noted Failure to Comply with TS 4.0.4 & TS 3/4.6.3, Civs. Caused by post-maint Testing That Did Not Adequately Test Control Circuitry & Verify Isolation Time Following Maint.Procedure Was Revised ML18016A9801999-06-0404 June 1999 LER 99-006-00:on 981124,failed to Comply with TS 4.0.4 & TS 3/4.6.3, Civ. Caused by post-maint Testing That Did Not Adequately Test Control Circuitry & Verify Isolation Time Following Maint.Procedure Will Be Revised.With 990604 Ltr ML18016A9111999-04-12012 April 1999 LER 99-005-00:on 990313,plant Exceeded ESFAS TS 3.3.2,Action 21.Caused by Inadequate Procedure Rev Preparation.Licensee Revised Applicable Maint Surveillance Test Procedure (MST-10072) to Identify TS Required Actions.With 990412 Ltr ML18016A8971999-04-0808 April 1999 LER 99-004-00:on 990312,unit Trip Was Noted.Caused by Degraded Condition of SG Water Level Flow Control Valve. Replaced Positioners on All Three FW Regulating Valves.With 990408 Ltr ML18016A8261999-02-22022 February 1999 LER 99-003-00:on 990123,noted That Plant Was Outside Design Basis Due to Isolation of Fire Protection Containment Sprinkler Sys.Caused by Human Error.Restored Containment Sprinkler Sys to Operable Status.With 990222 Ltr ML18016A8111999-02-12012 February 1999 LER 99-002-00:on 990114,RT Due to Not Removing Temporary Device from Relay Following Calibration Was Noted.Caused by Human Error.Counseled Personnel Involved in Event.With 990212 Ltr ML18016A7971999-02-0505 February 1999 LER 99-001-00:on 990106,SF Pool Water Level Was Not Maintained Greater than 23 Feet Above Stored BWR Fuel Assemblies.Caused by Fasteners Bending Under Specific Circumstances.Increased Water Level.With 990205 Ltr ML18016A7941999-01-29029 January 1999 LER 98-004-01:on 980313,identified Design Deficiency Re Potential Runout of Tdafwp.Caused by Inadequate Original AFW Sys Design.Operability Evaluation Was Completed on 980313 & Addl Engineering Analysis Was Performed by Vendor ML18016A7211998-11-17017 November 1998 LER 98-007-00:on 981023,turbine Control Anomaly Caused Manual Rt.Caused by Failure to Incorporate Verbal Vendor Guidance in Operating Procedures.Addl Vendor Guidance Will Be Verified & Added to Procedures.With 981117 Ltr ML18016A4841998-07-0707 July 1998 LER 97-002-01:on 970207,determined That Cold Weather Conditions Resulted in Mfiv Being Potentially Inoperable During Period 970117-20.Caused by Inadequate Design of HVAC Sys.Implemented Mods to Steam Tunnel HVAC Sys ML18016A4701998-06-30030 June 1998 LER 97-021-03:on 980210,discovered That SFP Water Level Had Not Been Verified Greater than 23 Feet Above BWR Fuel Assemblies.Caused by Misinterpretation of TS Requirements. Will Submit TS Change Request to Revise TS 3.9.1.11 ML18016A4491998-06-0808 June 1998 LER 98-006-00:on 980508,failure to Perform Insp & Preventive Maint on MCCB as Required by TS Was Noted.Caused by Inadequate Sps.Tested 9 Pressurizer Heater Bank Breakers by Cycling each.W/980608 Ltr ML18022B0551998-05-20020 May 1998 LER 98-005-00:on 980420,TS Verbatim non-compliance Was Determined.Caused by Misinterpretation of TS Requirements. Issued Memo to Reemphasize Need to Comply W/Literal Meaning of TS Requirements in Verbatim manner.W/980520 Ltr ML18016A4061998-04-30030 April 1998 LER 98-002-01:on 980121,determined Ssps (P-11 Permissive) Testing Deficiency.Caused by Inadequate Review of Initial Ts.Will Revise & Perform Surveillance Test Procedures to Verify Operability of P-11 Permissive ML18016A3841998-04-13013 April 1998 LER 98-004-00:on 980313,design Deficiency Related to Indequate Runout Protection for Turbine Driven AFW Pump Was Identified.Caused by Inadequate Original AFW Sys Design. Evaluation (ESR 98-00100) Will Be completed.W/980409 Ltr ML18016A3441998-03-12012 March 1998 LER 97-021-02:on 980210,identified Failure to Properly Test non-safety Related Pressurizer Porv.Caused by Inadequate Surveillance Test Procedures.Revised Operations Surveillance Test OST-1117 to Include Testing of Subject PORV ML18016A3291998-02-27027 February 1998 LER 98-003-00:on 980129,failure to Perform Shutdown Margin Calculation Required by TS Surveillance Requirements Occurred.Caused by Ambiguity in TS 3.1.3.1.c.Procedures revised.W/980227 Ltr ML18016A3211998-02-20020 February 1998 LER 98-002-00:on 980121,solid State Protection Sys Testing Deficiency Occurred.Caused by Inadequate Review of Initial Tech Specs.Ts Testing Frequency for P-11 Permissive Revised. W/980217 Ltr ML18016A3131998-02-0909 February 1998 LER 98-001-00:on 980109,potential Condition Outside Design Basis Related to Instrument Air Sys Leak Causing SG pre- Heater Bypass Isolation Valves to Be Inoperable Was Noted. Caused by Inadequate Design Control.Generated Jco 98-01 ML18016A2641997-12-18018 December 1997 LER 97-024-00:on 971118,SSPS Testing Deficiency Was Noted. Caused by Inadequate Testing Scheme Provided by Ssps Vendor. Revised procedure.W/971218 Ltr ML18016A2501997-11-24024 November 1997 LER 97-023-00:on 920721,RCS PIV Testing Deficiency Was Noted.Caused by Failure to Consider All Testing Variables During Initial Sp Development.Surveillance Tp OST-1506 Was Revised to Incorporate Correction factor.W/971124 Ltr ML18016A2201997-10-22022 October 1997 LER 97-021-01:on 970922,discovered That Spent Fuel Pool Water Level Was Not Maintained Greater than 23 Feet Above Stored BWR Fuel Assemblies.Caused by Misinterpretation of TS Requirements.Revised Daily Surveillance Procedures ML18016A2081997-10-14014 October 1997 LER 97-016-01:on 970608,reactor Trip Occurred,Due to Personnel Error While Attempting to Adjust Power Range Nuclear Instrumentation Channel Following Performance of Calorimetric.Procedures revised.W/971014 Ltr ML18016A2111997-10-14014 October 1997 LER 96-008-02:on 960425,turbine Trip/Reactor Trip Occurred. Caused by High Resistance Connection Resulting from a Phase Switch Jaw & Blade Contacts.Failed a Phase Disconnect Switch on Breaker 52-7 Replaced ML18016A1931997-09-29029 September 1997 LER 97-022-00:on 970829,TS Required Shutdown Due to Expiration of AFW Lco.Caused by Personnel Error.Completed Repairs TDAFW Pump & Returned Plant to Svc on 970831. W/970926 Ltr ML18016A1891997-09-12012 September 1997 LER 97-020-00:on 970814,inadequate Fire Protection Provided for safety-related EDG Fuel Oil Transfer Pump Cables Resulted in Operation Outside Design Basis.Caused by Engineering Oversight.Established Fire watches.W/970912 Ltr ML18016A1881997-09-12012 September 1997 LER 97-021-00:on 970814,spent Fuel Pool Water Level Was Not Maintained Greater than 23 Feet Above Stored BWR Fuel Assemblies.Caused by Misinterpretation of Ts.Directions Provided to Operations.W/970912 Ltr ML18012A8641997-08-18018 August 1997 LER 97-019-00:on 970720,turbine Trip/Reactor Trip Occurred. Caused by Three Phase Fault That Collapsed Excitation Field in Main Generator,Resulting in Generator Lockout.Exciter Rotor Assembly Was replaced.W/970818 Ltr ML18012A8581997-08-0808 August 1997 LER 96-018-01:on 960903,manual Reactor Trip Occurred Due to Loss of Normal Sw.Caused by Mechanical Failure of B Water Pump & a Normal SW to Remain Running Once Manually Started.Restored a Normal SW Pump to Svc ML18012A8551997-08-0808 August 1997 LER 96-013-02:on 961028,condition Outside of Design Basis Where RWST Had Been Aligned w/non-seismically Qualified Sys Was Identified.Caused by Failure to Reconcile Operating Procedure Lineups.Established Administrative Controls ML18012A8471997-07-31031 July 1997 LER 97-018-00:on 970701,determined That Plant Procedures Had Not Received Proper Reviews & Approvals.Caused by Failure to Comply W/Plant Administrative Procedure AP-006.Counseled Involved individuals.W/970731 Ltr ML18012A8371997-07-24024 July 1997 LER 97-S01-00:on 970405,unescorted Access Inappropriately Granted to Contract Outage Workers Was Determined.Caused by Personnel Error.Access Files for Individuals Inappropriately Granted Unescorted Access Were Placed on Access Hold ML18012A8291997-07-11011 July 1997 LER 97-017-00:on 970612,failed to Recognize Inoperable Reactor Afd Monitor.Caused by Personnel Error.Operators Involved in Event Will Be Counseled Prior to Assuming Shift duties.W/970711 Ltr ML18012A8301997-07-0808 July 1997 LER 97-016-00:on 970608,reactor Trip Occurred Due to Personnel Error in Adjusting Power Range (Pr) Nuclear Instrumentation (Ni).Issued Night Order Prohibiting Pr Ni Adjustment When Redundant Channel inoperable.W/970708 Ltr ML18012A8241997-07-0202 July 1997 LER 97-015-00:on 970602,inadequate Auxiliary Feedwater Sys Flow Control Valve Surveillance Testing Deficiency Was Identified.Caused by Failure to Recognize Impact on TS 4.7.1.2.1.Readjusted AFW FCV Actuator spring.W/970702 Ltr ML18022B0181997-06-13013 June 1997 LER 97-014-00:on 970514,SI Occurred During Ssps Surveillance Testing.Caused by Inattention to Detail During Recent Rev to Surveillance Test Procedure Being Used.Revised Deficient Surveillance procedures.W/970613 Ltr ML18012A8081997-06-0909 June 1997 LER 97-013-00:on 970508,entry Into Mode-6 Without Operable Components,Resulting in TS 3.0.4 Violation Occurred.Caused by Personnel Error.Personnel Involved counseled.W/970609 Ltr ML18012A8021997-06-0606 June 1997 LER 97-023-02:on 961114,design Deficiency Was Identified in Emergency DG Protection Circuitry.Caused by Inadequate Plant Design.Revised Surveillance Test Procedures OST-1013 & OST-1073.W/970606 Ltr ML18012A8011997-06-0404 June 1997 LER 97-012-00:on 970505,determined That Previous Auxiliary Control Panel Had Not Verified Operability of Interposing Relays.Caused by Misinterpretation of Tss.Reviewed Other Remote Shutdown Panel Transfer circuitry.W/970604 Ltr ML18012A7951997-05-29029 May 1997 LER 96-023-01:on 961114,design Deficiency in EDG Protection Circuitry Was Identified.Caused by Inadequate Original Plant Design.Surveillance Test Procedures OST-1013 & OST-1073 revised.W/970529 Ltr ML18012A7891997-05-22022 May 1997 LER 97-011-00:on 970422,inappropriate TS Interpretation Resulted in Violations of ECCS Accumulator TS & Entry Into TS 3.0.3.Caused by Procedural Inadequacy.Tsi 88-001 Cancelled 970508 & Procedures revised.W/970522 Ltr ML18012A7871997-05-19019 May 1997 LER 97-010-00:on 970418,design Deficiency Determined Re Reactor Coolant Pump Motor Oil Collection Sys.Caused by RCP Ocs Design Detail.Rcp Ocs Enclosures for Each of Three Installed RCP Motors Have Been modified.W/970519 Ltr ML18012A7761997-05-0707 May 1997 LER 97-009-00:on 970407,fuse Was Removed from CR Ventilation Isolation Signal Power Supply Circuitry Due to Personnel Error.Individuals Involved Were counseled.W/970507 Ltr ML18012A7751997-05-0505 May 1997 LER 97-008-00:on 970404,safety-related AHU Not Declared Inoperable During Maintenance on Associated Temperature Switches Resulting in Violation of Ts.Caused by Incorrect Interpretation.Operations Night Order issued.W/970505 Ltr ML18012A6291997-04-24024 April 1997 LER 97-007-00:on 970325,inoperable CCW Sys TS 3.0.3 Entry Made.Caused by Combination of Procedural Inadequacies, Improper Use of Procedure Guidance & Poor Communication. Applicable Individuals counseled.W/970423 Ltr ML18022B0151997-04-17017 April 1997 LER 97-006-00:on 970318,breach Was Identified in Thermo-Lag Fire Barrier Wall Due to Inadequate Initial Design,Poor Construction Methods & Incomplete as-built Design.Visual Insp of Thermo-Lag Barrier Walls performed.W/970417 Ltr ML18012A6041997-04-0303 April 1997 LER 97-004-00:on 970304,in-plant Spent Fuel Cask Handling Activities Conducted Outside Design Basis.Caused by Lack of Understanding of Requirements.Operations Placed on Hold Pending NRC Review & Approval of procedures.W/970331 Ltr ML18012A6031997-03-31031 March 1997 LER 97-003-00:on 970227,steam Generator Low Level Protection Circuitry Outside Design Basis Occurred.Caused by Inadequate Failure Modes & Effects Analysis Performed as-built Piping Configuration for S/G Level.Review performed.W/970331 Ltr 1999-09-10
[Table view] Category:RO)
MONTHYEARML18017A9181999-10-0808 October 1999 LER 99-008-00:on 991008,CR Emergency Filtration Sys Tech Specs Occurred.Caused by Site Personnel Failed to Recognize That Blocking Open CR Emergency Filtration Sys.Procedures Revised.With 991008 Ltr ML18017A8671999-09-10010 September 1999 LER 99-007-00:on 990811,determined That Cvis ARMs High Alarm Setpoints Were Not within TS Limit.Caused by Not Having Procedure to Verify If Cvis ARM High Alarm Setpoints Were within TS Requirements.Revised Procedures.With 990910 Ltr ML18016B0481999-08-0404 August 1999 LER 99-006-01:on 981124,noted Failure to Comply with TS 4.0.4 & TS 3/4.6.3, Civs. Caused by post-maint Testing That Did Not Adequately Test Control Circuitry & Verify Isolation Time Following Maint.Procedure Was Revised ML18016A9801999-06-0404 June 1999 LER 99-006-00:on 981124,failed to Comply with TS 4.0.4 & TS 3/4.6.3, Civ. Caused by post-maint Testing That Did Not Adequately Test Control Circuitry & Verify Isolation Time Following Maint.Procedure Will Be Revised.With 990604 Ltr ML18016A9111999-04-12012 April 1999 LER 99-005-00:on 990313,plant Exceeded ESFAS TS 3.3.2,Action 21.Caused by Inadequate Procedure Rev Preparation.Licensee Revised Applicable Maint Surveillance Test Procedure (MST-10072) to Identify TS Required Actions.With 990412 Ltr ML18016A8971999-04-0808 April 1999 LER 99-004-00:on 990312,unit Trip Was Noted.Caused by Degraded Condition of SG Water Level Flow Control Valve. Replaced Positioners on All Three FW Regulating Valves.With 990408 Ltr ML18016A8261999-02-22022 February 1999 LER 99-003-00:on 990123,noted That Plant Was Outside Design Basis Due to Isolation of Fire Protection Containment Sprinkler Sys.Caused by Human Error.Restored Containment Sprinkler Sys to Operable Status.With 990222 Ltr ML18016A8111999-02-12012 February 1999 LER 99-002-00:on 990114,RT Due to Not Removing Temporary Device from Relay Following Calibration Was Noted.Caused by Human Error.Counseled Personnel Involved in Event.With 990212 Ltr ML18016A7971999-02-0505 February 1999 LER 99-001-00:on 990106,SF Pool Water Level Was Not Maintained Greater than 23 Feet Above Stored BWR Fuel Assemblies.Caused by Fasteners Bending Under Specific Circumstances.Increased Water Level.With 990205 Ltr ML18016A7941999-01-29029 January 1999 LER 98-004-01:on 980313,identified Design Deficiency Re Potential Runout of Tdafwp.Caused by Inadequate Original AFW Sys Design.Operability Evaluation Was Completed on 980313 & Addl Engineering Analysis Was Performed by Vendor ML18016A7211998-11-17017 November 1998 LER 98-007-00:on 981023,turbine Control Anomaly Caused Manual Rt.Caused by Failure to Incorporate Verbal Vendor Guidance in Operating Procedures.Addl Vendor Guidance Will Be Verified & Added to Procedures.With 981117 Ltr ML18016A4841998-07-0707 July 1998 LER 97-002-01:on 970207,determined That Cold Weather Conditions Resulted in Mfiv Being Potentially Inoperable During Period 970117-20.Caused by Inadequate Design of HVAC Sys.Implemented Mods to Steam Tunnel HVAC Sys ML18016A4701998-06-30030 June 1998 LER 97-021-03:on 980210,discovered That SFP Water Level Had Not Been Verified Greater than 23 Feet Above BWR Fuel Assemblies.Caused by Misinterpretation of TS Requirements. Will Submit TS Change Request to Revise TS 3.9.1.11 ML18016A4491998-06-0808 June 1998 LER 98-006-00:on 980508,failure to Perform Insp & Preventive Maint on MCCB as Required by TS Was Noted.Caused by Inadequate Sps.Tested 9 Pressurizer Heater Bank Breakers by Cycling each.W/980608 Ltr ML18022B0551998-05-20020 May 1998 LER 98-005-00:on 980420,TS Verbatim non-compliance Was Determined.Caused by Misinterpretation of TS Requirements. Issued Memo to Reemphasize Need to Comply W/Literal Meaning of TS Requirements in Verbatim manner.W/980520 Ltr ML18016A4061998-04-30030 April 1998 LER 98-002-01:on 980121,determined Ssps (P-11 Permissive) Testing Deficiency.Caused by Inadequate Review of Initial Ts.Will Revise & Perform Surveillance Test Procedures to Verify Operability of P-11 Permissive ML18016A3841998-04-13013 April 1998 LER 98-004-00:on 980313,design Deficiency Related to Indequate Runout Protection for Turbine Driven AFW Pump Was Identified.Caused by Inadequate Original AFW Sys Design. Evaluation (ESR 98-00100) Will Be completed.W/980409 Ltr ML18016A3441998-03-12012 March 1998 LER 97-021-02:on 980210,identified Failure to Properly Test non-safety Related Pressurizer Porv.Caused by Inadequate Surveillance Test Procedures.Revised Operations Surveillance Test OST-1117 to Include Testing of Subject PORV ML18016A3291998-02-27027 February 1998 LER 98-003-00:on 980129,failure to Perform Shutdown Margin Calculation Required by TS Surveillance Requirements Occurred.Caused by Ambiguity in TS 3.1.3.1.c.Procedures revised.W/980227 Ltr ML18016A3211998-02-20020 February 1998 LER 98-002-00:on 980121,solid State Protection Sys Testing Deficiency Occurred.Caused by Inadequate Review of Initial Tech Specs.Ts Testing Frequency for P-11 Permissive Revised. W/980217 Ltr ML18016A3131998-02-0909 February 1998 LER 98-001-00:on 980109,potential Condition Outside Design Basis Related to Instrument Air Sys Leak Causing SG pre- Heater Bypass Isolation Valves to Be Inoperable Was Noted. Caused by Inadequate Design Control.Generated Jco 98-01 ML18016A2641997-12-18018 December 1997 LER 97-024-00:on 971118,SSPS Testing Deficiency Was Noted. Caused by Inadequate Testing Scheme Provided by Ssps Vendor. Revised procedure.W/971218 Ltr ML18016A2501997-11-24024 November 1997 LER 97-023-00:on 920721,RCS PIV Testing Deficiency Was Noted.Caused by Failure to Consider All Testing Variables During Initial Sp Development.Surveillance Tp OST-1506 Was Revised to Incorporate Correction factor.W/971124 Ltr ML18016A2201997-10-22022 October 1997 LER 97-021-01:on 970922,discovered That Spent Fuel Pool Water Level Was Not Maintained Greater than 23 Feet Above Stored BWR Fuel Assemblies.Caused by Misinterpretation of TS Requirements.Revised Daily Surveillance Procedures ML18016A2081997-10-14014 October 1997 LER 97-016-01:on 970608,reactor Trip Occurred,Due to Personnel Error While Attempting to Adjust Power Range Nuclear Instrumentation Channel Following Performance of Calorimetric.Procedures revised.W/971014 Ltr ML18016A2111997-10-14014 October 1997 LER 96-008-02:on 960425,turbine Trip/Reactor Trip Occurred. Caused by High Resistance Connection Resulting from a Phase Switch Jaw & Blade Contacts.Failed a Phase Disconnect Switch on Breaker 52-7 Replaced ML18016A1931997-09-29029 September 1997 LER 97-022-00:on 970829,TS Required Shutdown Due to Expiration of AFW Lco.Caused by Personnel Error.Completed Repairs TDAFW Pump & Returned Plant to Svc on 970831. W/970926 Ltr ML18016A1891997-09-12012 September 1997 LER 97-020-00:on 970814,inadequate Fire Protection Provided for safety-related EDG Fuel Oil Transfer Pump Cables Resulted in Operation Outside Design Basis.Caused by Engineering Oversight.Established Fire watches.W/970912 Ltr ML18016A1881997-09-12012 September 1997 LER 97-021-00:on 970814,spent Fuel Pool Water Level Was Not Maintained Greater than 23 Feet Above Stored BWR Fuel Assemblies.Caused by Misinterpretation of Ts.Directions Provided to Operations.W/970912 Ltr ML18012A8641997-08-18018 August 1997 LER 97-019-00:on 970720,turbine Trip/Reactor Trip Occurred. Caused by Three Phase Fault That Collapsed Excitation Field in Main Generator,Resulting in Generator Lockout.Exciter Rotor Assembly Was replaced.W/970818 Ltr ML18012A8581997-08-0808 August 1997 LER 96-018-01:on 960903,manual Reactor Trip Occurred Due to Loss of Normal Sw.Caused by Mechanical Failure of B Water Pump & a Normal SW to Remain Running Once Manually Started.Restored a Normal SW Pump to Svc ML18012A8551997-08-0808 August 1997 LER 96-013-02:on 961028,condition Outside of Design Basis Where RWST Had Been Aligned w/non-seismically Qualified Sys Was Identified.Caused by Failure to Reconcile Operating Procedure Lineups.Established Administrative Controls ML18012A8471997-07-31031 July 1997 LER 97-018-00:on 970701,determined That Plant Procedures Had Not Received Proper Reviews & Approvals.Caused by Failure to Comply W/Plant Administrative Procedure AP-006.Counseled Involved individuals.W/970731 Ltr ML18012A8371997-07-24024 July 1997 LER 97-S01-00:on 970405,unescorted Access Inappropriately Granted to Contract Outage Workers Was Determined.Caused by Personnel Error.Access Files for Individuals Inappropriately Granted Unescorted Access Were Placed on Access Hold ML18012A8291997-07-11011 July 1997 LER 97-017-00:on 970612,failed to Recognize Inoperable Reactor Afd Monitor.Caused by Personnel Error.Operators Involved in Event Will Be Counseled Prior to Assuming Shift duties.W/970711 Ltr ML18012A8301997-07-0808 July 1997 LER 97-016-00:on 970608,reactor Trip Occurred Due to Personnel Error in Adjusting Power Range (Pr) Nuclear Instrumentation (Ni).Issued Night Order Prohibiting Pr Ni Adjustment When Redundant Channel inoperable.W/970708 Ltr ML18012A8241997-07-0202 July 1997 LER 97-015-00:on 970602,inadequate Auxiliary Feedwater Sys Flow Control Valve Surveillance Testing Deficiency Was Identified.Caused by Failure to Recognize Impact on TS 4.7.1.2.1.Readjusted AFW FCV Actuator spring.W/970702 Ltr ML18022B0181997-06-13013 June 1997 LER 97-014-00:on 970514,SI Occurred During Ssps Surveillance Testing.Caused by Inattention to Detail During Recent Rev to Surveillance Test Procedure Being Used.Revised Deficient Surveillance procedures.W/970613 Ltr ML18012A8081997-06-0909 June 1997 LER 97-013-00:on 970508,entry Into Mode-6 Without Operable Components,Resulting in TS 3.0.4 Violation Occurred.Caused by Personnel Error.Personnel Involved counseled.W/970609 Ltr ML18012A8021997-06-0606 June 1997 LER 97-023-02:on 961114,design Deficiency Was Identified in Emergency DG Protection Circuitry.Caused by Inadequate Plant Design.Revised Surveillance Test Procedures OST-1013 & OST-1073.W/970606 Ltr ML18012A8011997-06-0404 June 1997 LER 97-012-00:on 970505,determined That Previous Auxiliary Control Panel Had Not Verified Operability of Interposing Relays.Caused by Misinterpretation of Tss.Reviewed Other Remote Shutdown Panel Transfer circuitry.W/970604 Ltr ML18012A7951997-05-29029 May 1997 LER 96-023-01:on 961114,design Deficiency in EDG Protection Circuitry Was Identified.Caused by Inadequate Original Plant Design.Surveillance Test Procedures OST-1013 & OST-1073 revised.W/970529 Ltr ML18012A7891997-05-22022 May 1997 LER 97-011-00:on 970422,inappropriate TS Interpretation Resulted in Violations of ECCS Accumulator TS & Entry Into TS 3.0.3.Caused by Procedural Inadequacy.Tsi 88-001 Cancelled 970508 & Procedures revised.W/970522 Ltr ML18012A7871997-05-19019 May 1997 LER 97-010-00:on 970418,design Deficiency Determined Re Reactor Coolant Pump Motor Oil Collection Sys.Caused by RCP Ocs Design Detail.Rcp Ocs Enclosures for Each of Three Installed RCP Motors Have Been modified.W/970519 Ltr ML18012A7761997-05-0707 May 1997 LER 97-009-00:on 970407,fuse Was Removed from CR Ventilation Isolation Signal Power Supply Circuitry Due to Personnel Error.Individuals Involved Were counseled.W/970507 Ltr ML18012A7751997-05-0505 May 1997 LER 97-008-00:on 970404,safety-related AHU Not Declared Inoperable During Maintenance on Associated Temperature Switches Resulting in Violation of Ts.Caused by Incorrect Interpretation.Operations Night Order issued.W/970505 Ltr ML18012A6291997-04-24024 April 1997 LER 97-007-00:on 970325,inoperable CCW Sys TS 3.0.3 Entry Made.Caused by Combination of Procedural Inadequacies, Improper Use of Procedure Guidance & Poor Communication. Applicable Individuals counseled.W/970423 Ltr ML18022B0151997-04-17017 April 1997 LER 97-006-00:on 970318,breach Was Identified in Thermo-Lag Fire Barrier Wall Due to Inadequate Initial Design,Poor Construction Methods & Incomplete as-built Design.Visual Insp of Thermo-Lag Barrier Walls performed.W/970417 Ltr ML18012A6041997-04-0303 April 1997 LER 97-004-00:on 970304,in-plant Spent Fuel Cask Handling Activities Conducted Outside Design Basis.Caused by Lack of Understanding of Requirements.Operations Placed on Hold Pending NRC Review & Approval of procedures.W/970331 Ltr ML18012A6031997-03-31031 March 1997 LER 97-003-00:on 970227,steam Generator Low Level Protection Circuitry Outside Design Basis Occurred.Caused by Inadequate Failure Modes & Effects Analysis Performed as-built Piping Configuration for S/G Level.Review performed.W/970331 Ltr 1999-09-10
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML18017A9181999-10-0808 October 1999 LER 99-008-00:on 991008,CR Emergency Filtration Sys Tech Specs Occurred.Caused by Site Personnel Failed to Recognize That Blocking Open CR Emergency Filtration Sys.Procedures Revised.With 991008 Ltr ML18017A9151999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for Shearon Harris Npp. with 991012 Ltr ML20217A9931999-09-30030 September 1999 NRC Regulatory Assessment & Oversight Pilot Program, Performance Indicator Data ML18017A8671999-09-10010 September 1999 LER 99-007-00:on 990811,determined That Cvis ARMs High Alarm Setpoints Were Not within TS Limit.Caused by Not Having Procedure to Verify If Cvis ARM High Alarm Setpoints Were within TS Requirements.Revised Procedures.With 990910 Ltr ML18017A8621999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Harris Nuclear Plant.With 990908 Ltr ML18016B0481999-08-0404 August 1999 LER 99-006-01:on 981124,noted Failure to Comply with TS 4.0.4 & TS 3/4.6.3, Civs. Caused by post-maint Testing That Did Not Adequately Test Control Circuitry & Verify Isolation Time Following Maint.Procedure Was Revised ML18017A8361999-07-31031 July 1999 Monthly Operating Rept for July 1999 for Shearon Harris Nuclear Power Plant.With 990811 Ltr ML18016B0151999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Shearon Harris Npp. with 990713 Ltr ML20196H8621999-06-30030 June 1999 NRC Regulatory Assessment & Oversight Pilot Program, Performance Indicator Data, June 1999 Rept ML18016A9801999-06-0404 June 1999 LER 99-006-00:on 981124,failed to Comply with TS 4.0.4 & TS 3/4.6.3, Civ. Caused by post-maint Testing That Did Not Adequately Test Control Circuitry & Verify Isolation Time Following Maint.Procedure Will Be Revised.With 990604 Ltr ML18016A9851999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Shearon Harris Nuclear Plant,Unit 1.With 990614 Ltr ML18017A8981999-05-12012 May 1999 Technical Rept Entitled, Harris Nuclear Plant-Bacteria Detection in Water from C&D Spent Fuel Pool Cooling Lines. ML18016A9581999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Shearon Harris Nuclear Plant,Unit 1.With 990513 Ltr ML18016A9011999-04-12012 April 1999 Part 21 Rept Re Defect in Component of DSRV-16-4,Enterprise DG Sys.Caused by Potential Problem with Connecting Rod Assemblies Built Since 1986,that Have Been Converted to Use Prestressed Fasteners.Affected Rods Should Be Inspected ML18016A9111999-04-12012 April 1999 LER 99-005-00:on 990313,plant Exceeded ESFAS TS 3.3.2,Action 21.Caused by Inadequate Procedure Rev Preparation.Licensee Revised Applicable Maint Surveillance Test Procedure (MST-10072) to Identify TS Required Actions.With 990412 Ltr ML18016A8971999-04-0808 April 1999 LER 99-004-00:on 990312,unit Trip Was Noted.Caused by Degraded Condition of SG Water Level Flow Control Valve. Replaced Positioners on All Three FW Regulating Valves.With 990408 Ltr ML18016A8941999-04-0505 April 1999 Revised Pages 20-25 to App 4A of non-proprietary Version of Rev 3 to HI-971760 ML18016A9101999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Shearon Harris Nuclear Power Plant.With 990413 Ltr ML18016A8661999-03-31031 March 1999 Shnpp Operator Training Simulator,Simulator Certification Quadrennial Rept. ML18017A8931999-02-28028 February 1999 Risks & Alternative Options Associated with Spent Fuel Storage at Shearon Harris Nuclear Power Plant. ML18016A8551999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Shearon Harris Npp. with 990312 Ltr ML18016A8261999-02-22022 February 1999 LER 99-003-00:on 990123,noted That Plant Was Outside Design Basis Due to Isolation of Fire Protection Containment Sprinkler Sys.Caused by Human Error.Restored Containment Sprinkler Sys to Operable Status.With 990222 Ltr ML18016A8531999-02-18018 February 1999 Non-proprietary Rev 3 to HI-971760, Licensing Rept for Expanding Storage Capacity in Harris SFP 'C' & 'D'. ML18016A8111999-02-12012 February 1999 LER 99-002-00:on 990114,RT Due to Not Removing Temporary Device from Relay Following Calibration Was Noted.Caused by Human Error.Counseled Personnel Involved in Event.With 990212 Ltr ML18016A7971999-02-0505 February 1999 LER 99-001-00:on 990106,SF Pool Water Level Was Not Maintained Greater than 23 Feet Above Stored BWR Fuel Assemblies.Caused by Fasteners Bending Under Specific Circumstances.Increased Water Level.With 990205 Ltr ML18022B0631999-02-0404 February 1999 Rev 0 to Nuclear NDE Manual. with 28 Oversize Uncodable Drawings of Alternative Plan Scope & 4 Oversize Codable Drawings ML20202J1161999-02-0101 February 1999 SER Accepting Relief Requests Associated with Second 10-year Interval Inservice Testing Program ML18016A8041999-01-31031 January 1999 Monthly Operating Rept for Jan 1999 for Shearon Harris Nuclear Power Plant.With 990211 Ltr ML18016A7941999-01-29029 January 1999 LER 98-004-01:on 980313,identified Design Deficiency Re Potential Runout of Tdafwp.Caused by Inadequate Original AFW Sys Design.Operability Evaluation Was Completed on 980313 & Addl Engineering Analysis Was Performed by Vendor ML18016A7801998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for Shearon Harris Npp. with 990113 Ltr ML18016A7671998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Shnpp,Unit 1.With 981215 Ltr ML18016A9731998-11-28028 November 1998 Changes,Tests & Experiments, for Harris Nuclear Plant.Rept Provides Brief Description of Changes to Facility & Summary & of SE for Each Item That Was Implemented Under 10CFR50.59 Between 970608-981128.With 990527 Ltr ML18016A8351998-11-28028 November 1998 ISI Summary 8th Refueling Outage for Shearon Harris Power Plant,Unit 1. ML18016A7411998-11-25025 November 1998 Rev 1 to Shnpp Cycle 9 Colr. ML18016A7211998-11-17017 November 1998 LER 98-007-00:on 981023,turbine Control Anomaly Caused Manual Rt.Caused by Failure to Incorporate Verbal Vendor Guidance in Operating Procedures.Addl Vendor Guidance Will Be Verified & Added to Procedures.With 981117 Ltr ML18016A7071998-11-0303 November 1998 Rev 0 to Harris Unit 1 Cycle 9 Colr. ML18016A7201998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Shearon Harris Nuclear Power Plant.With 981113 Ltr ML20154F8701998-10-0606 October 1998 Safety Evaluation Authorizing Proposed Alternative to Requirements of OMa-1988,Part 10,Section 4.2.2.3 for 21 Category a Reactor Coolant Sys Pressure Isolation Valves ML18016A6201998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Harris Nuclear Power Plant.With 981012 Ltr ML18016A5971998-09-21021 September 1998 Rev 1 to Harris Unit 1 Cycle 8 Colr. ML18016A5881998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for Shnpp,Unit 1.With 980914 Ltr ML18016A5071998-07-31031 July 1998 Monthly Operating Rept for Jul 1998 for Shearon Harris Nuclear Plant.W/980811 Ltr ML18016A9431998-07-0707 July 1998 Rev 1 to QAP Manual. ML18016A4841998-07-0707 July 1998 LER 97-002-01:on 970207,determined That Cold Weather Conditions Resulted in Mfiv Being Potentially Inoperable During Period 970117-20.Caused by Inadequate Design of HVAC Sys.Implemented Mods to Steam Tunnel HVAC Sys ML18016A9371998-06-30030 June 1998 Technical Rept on Matl Identification of Spent Fuel Piping Welds at Hnp. ML18016A4861998-06-30030 June 1998 Monthly Operating Rept for June 1998 for SHNPP.W/980715 Ltr ML18016A4701998-06-30030 June 1998 LER 97-021-03:on 980210,discovered That SFP Water Level Had Not Been Verified Greater than 23 Feet Above BWR Fuel Assemblies.Caused by Misinterpretation of TS Requirements. Will Submit TS Change Request to Revise TS 3.9.1.11 ML18016A4491998-06-0808 June 1998 LER 98-006-00:on 980508,failure to Perform Insp & Preventive Maint on MCCB as Required by TS Was Noted.Caused by Inadequate Sps.Tested 9 Pressurizer Heater Bank Breakers by Cycling each.W/980608 Ltr ML18016A4521998-05-31031 May 1998 Monthly Operating Rept for May 1998 for Shearon Harris Nuclear Power Plant.W/980612 Ltr ML18016A7711998-05-26026 May 1998 Non-proprietary Rev 2 to HI-971760, Licensing Rept for Expanding Storage Capacity in Harris Spent Fuel Pools 'C' & 'D'. 1999-09-30
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~ CATEGORY 1 REGULATORY INFORMATION DISTRIBUTION SYSTEM (RZDS)
ACCESSION NBR:9605310228 DOC.DATE: 96/05/28 NOTARIZED: NO DOCKET I FACIL:50-400 Shearon Harris Nuclear Power Plant,,Unit 1, Carolina 05000400 AUTH. NAME AUTHOR AFFILIATION CHAPLIN,S. Carolina Power & Light Co.
DONAHUE,J.W. Carolina Power & Light Co.
I REC P . NAME RECIPIENT AFFILIATION
SUBJECT:
LER 96-008-00:on 960425,turbine/trip reactor trip occurred due to main generator lockout. Caused by failure of output breaker disconnect. Failed A phase disconnect switch on Breaker 52-7 replaced.W/960528 ltr.
DISTRIBUTION CODE: IE22T COPIES RECEIVED:L'TR ENCL SIZE:
TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc. E NOTES:Application for permit renewal filed. 05000400 G 0
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ZD CODE/NAME LTTR ENCL R PD2-1 PD 1 1 LE,N 1 1 INTERNAL: ACRS 1 1 A 2 2 AEOD/SPD/RRAB 1 1 LE CENTER 1 1 NRR/DE/ECGB 1 1 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 D RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 0
EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J.H 2 2 NOAC MURPHY,G.A 1 1 NOAC POORE,W. 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 N
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FI Carolina Power R Light Company Harris Nuclear Plant PO Box 165 New Hill NC 27562 MAY 28 t996 U.S. Nuclear Regulatory Commission Serial: HNP-96-090 ATTN: NRC Document Control Desk 10CFR50.73 Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LI ENSEE EVENT REP RT 6-008-00 Gentlemen:
In accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report relates to the reactor trip due to failure of an output breaker disconnect.
Sincerely, J. W. Donahue General Manager Harris Plant SDC Enclosure c: Mr. J. B. Brady (NRC - HNP)
Mr. S. D. Ebneter (NRC - RII)
Mr. N. B. Le (NRC - PM/NRR) 9605310228 9605+8 PDR ADQCK 05000600 f J)R 350073 State Road 1134 New Hill NC
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB No. 3150.0104 (405) EXPIRES 04/30/96 ESTNATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLIECTION REOUESTI 500 HRS. REPORTED LESSONS LEARNED ARE LICENSEE EVENT REPORT (LER) INCORPORATED INTO THE UCENSUIG PROCESS ANO FED BACK TO INDUSTRY.
FORWARD COMMENTS REGARDUIG BURDEN ESTIMATE TO THE UIFORMATION AND RECORDS MANAGEMENT BRANCH IT4I f33L U.S. NUCLEAR REGUlATORY COMMISSION, (see reverse for required number of WASSNGTON, DC 205550001, AND TO THE PAPERWORK REDUCTION PROJECT (3150 0104L OFFICE OF MANAGEMENT ANO BUDGET. WASHINGTON, DC 20503.
digits/characters for each block)
FACIUTY NAME II) DOCKET NUMBER I2l PAGE fs)
Harris Nuclear Plant - Unit 1 50-400 1 OF6 TITLE f4I Reactor Trip due to Failure of an output breaker disconnect device.
EVENT DATE (5) LER NUMBER (6I REPORT DATE (7I OTHER FACILITIES INVOLVED (6)
FACILITYNAME DOCKET NUMBER SEQUENTIAL REVISION MONTH DAY YEAR MONTH OAY YEAR NUMBER NUMBER 05000 FACILITY NAME DOCKET NUMBER 04 25 96 96 008 00 05 28 96 05000 OPERATING REPORT IS SUBMITTED PUR SUANT TO THE REQUIREMENTS OF 10 CFR II: (Check one or more) I11)
MODE (9) '20.2201(b) 20.2203(a)(2)(v) 50.73(a)(2)(i) 50.73(c)(2)(viii) ooor'HIS20.2203(a) (1) 20.2203(a) (3) (i) 50.73(a) (2) (ii) 50.73(a) (2) (x)
POWER LEVEL (10) 1 20.2203(a)(2)(il 20.2203(a) (3)(ii) 50.73(a)(2)(iii) 73.71 20.2203(a) (2) (ii) 20.2203(a)(4) X 50.73(a)(2)(iv) OTHER
- 20. 2203(a) (2) (iii) 50.36(c)(1) 50.73(a) (2) (v) Specrfy In Abstract below or in NRC Form 366A 20.2203(a) (2l(iv) 50.36(c)(2) 50.73(a)(2) (vii)
LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER Urrerude Area Codel Steven Chaplin, Senior Engineer - Licensing/Regulatory Programs {919) 362-2113 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
REPORTABLE REPOR'FABLE CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYS'FEM COMPONENT MANUFACTURER TO NPROS TO NPRDS EL Disc M230 KE RLY W120 SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MOIITH DAY YEAR SUBMISSION X YEs EXPECTED SUBMISSION DATE).
No DATE (15) 8 .15 96 (lf yes, complete ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single spaced typewritten lines) (16)
On April 25, 1996 at approximately 2107 with the unit operating in Mode 1 at 100% power, a turbine trip/reactor trip occurred due to a main generator lockout. The generator!ockout was caused by the failure of a manual disconnect for one of two unit output breakers. At the time of the failure, the full generator output was being routed through the breaker whose disconnect failed. It is believed that a false under-voltage signal occured during the fast transfer of feed to the 1E bus IB train bus) to the Startup Auxiliary Transformer. The under-voltage signal resulted in the loss of power to several electrical busses. Secondary system equipment was secured due to the loss of Normal Service Water. The "A" Emergency Service Water pump started and supplied its header. The "8" the of Offsite Power sequencer program to start. Appropriate "8" train safety bus under-voltage signal caused Loss equipment started as required. The "A" train successfully completed a fast transfer to the Startup Auxiliary Transformer. However, the "A" Emergency Diesel Generator was found to be in the "Operational" mode but the "Maintenance" mode status lights were on, indicating a circuitry problem. Isolation signals were received for the Containment and Control Room Isolation Systems due to radiation monitor power loss. At approximately 2152, it was noted that the Charging/Safety Injection Pump suction had transferred from the Volume Control Tank (VCT) to the Refueling Water Storage Tank. The swapoyer occurred due to the loss of electrical power to the boric acid flow transmitter. Operators stabilized the unit in Mode 3. The "A" disconnect failure was preliminarily attributed to inadequate maintenance. The investigation is continuing. The and "8" phase disconnects for the affected breaker were replaced and the other switchyard disconnect switches were inspected for proper seating. After returning the unit to service, thermography monitoring of the unit output breaker disconnects showed elevated temperatures. The unit was taken offline and the disconnect contacts on the generator bus sides of the unit output breakers were refurbished. The unit returned to service and subsequent thermography readings indicated expected operating temperatures for the disconnects.
NRC ORM 300 I4 >I
NRC FORM a66A U.S. NUCLEAR REGULATORY COMMISSION (4RB)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (I) OOCXET LER NUMBER (6) PAGE (3)
SEQUEt(TIAL REYISIOt(
t(UMBER NUMBER Harris Nuclear Plant ~
Unit I 50 400 2 OF 6 06 - 008 - 00 TEXT dl ososo spssois sspsisd, oso sddsu'oosl solo'os ol llltC lsdso SFFAS (lt)
EVENT DESCRIPTIOM:
There are two 100% capacity unit output breakers, designated 52-7 and 52-9, which connect the main generator to the main switchyard south and north 230 KV buses, respectively. The breakers have manual disconnects on both the generator and 230 KV bus sides. Each disconnect has three poles designated A phase, B phase and C "
phase. On April 25, 1996, at approximately 2045, Breaker 52-9 was taken out of service for maintenance, resulting in the full generator output being routed through Breaker 52-7. At approximately 2107 on April 25, 1996, with the unit operating in Mode 1 at 100% power, the A phase disconnect pole on the generator side of unit output Breaker 52-7 failed [EIIS Code:EL-DISC ). This failure resulted in a short to ground which caused a generator lockout, a turbine trip and a reactor trip.
The resulting electrical perturbation caused several busses to lose power which caused the B Normal Service Water Pump to trip. (NSW, EIIS Code: KG-P). Operating personnel secured the running secondary plant equipment, including both main feedwater pumps, and broke condenser vacuum. Operators stabilized the unit in Mode 3.
Five Engineered Safety Features Actuation System (ESFAS) signals were generated during the event: the reactor trip, the start of the 8 Emergency Diesel generator (EDG), the start of the AFW pumps on low low steam generator level, the containment ventilation isolation signal and the control room isolation signal.
The following describes specific equipment performance noted following the unit trip:
An electrical perturbation initiated a load shed on non-safety AC bus 1E resulting in a loss of power to busses 1E-1, 1E-2, 1E-3, half of the General Services bus (bus 1-4A, Section 2), and the B safety bus. The most likely cause for the loss of the 6.9 KV non-safety bus 1E is a momentary contact closure of an under-voltage sensing relay during the fast transfer from the Unit Auxiliary Transformer to the Start up Auxiliary Transformer. The momentary contact closure provided a false under-voltage signal. The momentary contact closure appears to have been induced by physical agitation of the relay during operation of two 6.9 KV breakers during the fast transfer. Since an actual under-voltage condition did not exist, the Under-voltage Lockout Relay 86UV/E electrically reset (EIIS Code: EA-RLY27). Investigation and confirmatory testing of this scenario is still in progress.
The loss of power to B safety bus deenergized several radiation monitors causing actuations, including both a Containment Ventilation and Control Room Isolation Signals.
The Digital Rod Position Indicator system lost power due to deenergization of the bus 1E-2. Power to this system was restored at approximately 2209 and full insertion of the control rods was verified.
As described above, the electrical perturbation isolated the feed for the B safety bus and automatically started the B EDG (EIIS Code: EK-DG). Appropriate B train safety equipment started as required via the emergency sequencer.
NRC FORM 366A U.S. NUCLEAR REGULATORT COMMISSION (496)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FAG(LITT NAME (I) DOCKET LER NUMBER (6) PAGE(3)
SEDU(NTIAL RETISION I TEAR INMB(R NUMBER Harris Nuclear Plant ~ Unit 1 50 400 3 OF 6 96 - 008 00 TEXT /// aar odooo /o oorri od, roo oddddooo/ or/oi r o//YRC /aa SFQI (Ill The standby A NSW pump did not start automatically when the 8 NSW pump tripped. The failure of the A NSW to start appears to be the result of the short time period the under-voltage signal was present. The under-voltage signal is estimated to have been present for approximately 50 milliseconds, i.e., a duration equivalent to the reset time of the Under-voltage Lockout Relay 86UV/E. The automatic start circuitry for the A NSW pump has two relays in series, each with a pick-up time of approximately 50 milliseconds. Therefore, the under-voltage signal duration would have had to been present for at least 100 milliseconds to automatically start the A NSW pump.
The A EDG did not receive an emergency start signal during the event due to the successful transfer to the Start up Auxiliary Transformer. However, the operability of the A EDG was initially questioned due to conflicting status indications and was reported as such in the 4-Hour NRC Event Notification pursuant to 10 CFR 50.72(b)(2). Soon after the unit trip, an operator observed that the "Maintenance" mode status lights were illuminated for the A EDG even though the "Operational" mode was selected. Control room indications showed that the A EDG had received a stop signal. A possible cause of the conflicting status light display was a trip of the 86DG lockout relay (EIIS Code: EK-RLY86) from a transient or induced voltage in the control circuitry of the Generator Control Panel. If an emergency start signal had been present during or after the transient, the 86DG lockout relay would have reset and the A EDG would have started. Additional testing of the 86DG lockout relay in the A EDG control circuitry is planned in an attempt to duplicate the 86DG lockout relay trip.
While the operators were stabilizing the unit after the reactor trip and taking actions associated with the loss of the AC busses, full AFW flow to the steam generators resulted in Reactor Coolant System (RCS) temperature decreasing below the normal no-load temperature of 557 degrees F to approximately 537 degrees F. The RCS coo!down caused a decrease in the pressurizer level and a resulting increase in charging flow. The RCS letdown isolated at 17% pressurizer level. Automatic level control of the Volume Control Tank (VCT) did not function due to loss of power from bus 1E-2 to the boric acid flow transmitter. At approximately 2113, the VCT level decreased to 5% and the Charging/Safety Injection Pumps suction automatically transferred to the Refueling Water Storage Tank (RWST) as designed. The Reactor Operator did not detect the VCT low level alarm, nor the fact that the suction of the charging pumps automatically switched to the RWST, until a RWST Low Level Alarm was received at approximately 2152. (The lowest recorded RWST level was 94% which is greater than the Technical Specification required minimum of 92%).
The AFW flow was reduced when directed by procedure, and the RCS temperature returned to its normal value of 557 degrees F at approximately 2131.
At approximately 2245 hours0.026 days <br />0.624 hours <br />0.00371 weeks <br />8.542225e-4 months <br />, operators manually started the A NSW pump. The discharge valve did not open and the valve opening timer did not trip the pump. Operators manually tripped the pump from the 6.9 KV breaker. Subsequent investigation concluded that Control Relay CR1/2189 (EIIS Code: KE-RLY) in the pump's discharge valve circuitry did not pick up and latch-in. This control relay failure caused both the failure of the valve to open and the failure of the pump to trip. The mechanical latch on the control relay was adjusted and the pump was subsequently started successfully.
At approximately 2255, operators manually started the B NSW pump. Indications in the Main Control Room showed the pump started and tripped approximately 30 seconds later. Subsequent investigations have not determined the cause of the failure. On subsequent attempts the pump started and the discharge valve opened as designed. It is suspected that the cause of the pump trip was an intermittent problem associated with Control Relay CR4/2190 (EIIS Code:KE-RLY) that did not recur during the trouble shooting. Control Relay CR4/2190 was subsequently replaced on May 23, 1996.
P, U.S. NUCLEAR REGULATORY COMMISSION NRC FORM SSGA (4 96(
LICENSEE EVENT BEPOBT ILEB)
TEXT CONTINUATION DOCKET LER NUMBER (6) PAGE (SI FACILITY NAME ((I SEOU(NTIAL REVISION NUMBER NUMBER Harris Nuclear Plant ~ Unit I 50400 4 OF 6 86 - 008 - 00 TEXT lllucvo shoo u ooroiod. voo oddiu'oool oopiro ol HRC fa'oo SFFAI ((TI During evaluation of Emergency Response Facility Information System IERFIS) data from the reactor trip, it appeared that the pressurizer pressure master controller did not energize the backup heaters at the proper set point, and automatic energization of the B group of backup heaters was not blocked by the B sequencer operation. These items are still under investigation.
'AUSE:
The failure of the A phase disconnect for unit output Breaker 52-7 was due to a high resistance connection resulting from the A phase switch jaw and blade cor(tacts not being fully closed (blade not rotated into the horizontal position). The reason for the switch not being fully closed is attributed to a misalignment in the mechanical linkage of the closing mechanism. High contact resistance, identified using thermography, was also noted on other breaker disconnects which did not fail. These conditions are preliminarily attributed to inadequate preventive maintenance.
Investigation is continuing.
SAFETY SIGNIFICANCE:
There were no significant safety consequences as a result of this event. The reactor tripped and the control rods fully inserted. The event challenged the automatic swapover of the unit auxiliaries to the Startup Auxiliary Transformer and initiated an under-voltage startup of the B EDG. Safety systems responded as required to ensure unit safety and operators stabilized the unit in Mode 3.
This event is being reported per 10 CFR 50.73(a)I2)(iv).
PREVIOUS SIMILAR EVENTS:
There have been no reactor trips caused by a switchyard breaker disconnect.
CORRECTIVE ACTIONS COMPLETED:
The following actions were performed prior to returning the unit to service on April 28, 1996:
- 1. The failed A phase. disconnect switch on Breaker 52-7 was replaced. Pitted contacts on the B phase blade and jaw were also replaced. The switch was adjusted and proper operation was verified.
- 2. The bus side disconnect switches on Breakers 52-7 and 52-9 were visually inspected with no problems identified. The unit side disconnect switch on the Breaker 52-9 was visually inspected and proper operation verified.
- 3. Transmission Department personnel provided initial training to some unit operations personnel on recognizing correct disconnect alignment.
- 4. The mechanical latch on the A NSW Pump discharge valve Control Relay CR1/2189 was adjusted.
NRC FORM SBSA U.S. NUCLEAR REGULATORY COMMISSION (4.BQ LICEIIISEE EVEIIIT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (II oocxrr LER NUMBER (SI PAGE(S)
SERUaiTIAL REVISION YEAR IIUMBER NUMBER Harris Nuclear Plant ~ Unit I 50400 5 OF 6 86 - 008 00 TEXT illsooso suosois sorodsd srso oddiu'oool sopos ol h'RC dosos MLS (IT)
Control Relay CR4/2190 for the 8 NSW Pump was replaced.
An assessment of control room operations staff performance was conducted. The review identified several areas where operator performance can be improved, including proactive control of key unit parameters such as AFW flow and recognition of some off-normal conditions.
The remainder of the disconnects in the switchyard were inspected to verify that blade contacts were properly seated. No other abnormally positioned disconnects were identified.
Following restart of the unit, the temperature of disconnect switches on Breakers 52-7 and 52-9 remained high as determined using infrared thermography . On May 3, 1996, the unit was removed from service and the disconnect contacts on the both the generator and bus sides of Breakers 52-7 and 52-9 were replaced.
Contact resistance measurements verified successful repair of the breaker disconnect switches. After'unit
.restart, thermography monitoring indicated expected operating temperatures.
CORRECTIVE ACTIONS PLANNED:
- 1. Complete investigation of the pressurizer pressure control by June 25, 1996.
Investigation and confirmatory testing of the under-voltage relay momentary contact closure and associated false under-voltage signal will be completed by July 1, 1996.
- 3. Additional testing in an effort to duplicate the 86DG lockout relay trip in the A EDG control circuitry is
'planned. This testing will be completed by July 1, 1996.
- 4. The Superintendents-Shift Operations will brief appropriate operations personnel on the assessment of control room operation staff performance. This briefing will be completed by July 1, 1996.
- 5. The preventive maintenance requirements for switchyard maintenance and operator inspections will be revised by September 30, 1996, which is prior to the next refueling outage currently scheduled to commence in March 1997.
- 6. Training will be provided to the operators regarding proper operation of the breaker disconnects. This training will be completed by October 7, 1996.
- 7. Licensed operators will be briefed on the importance of throttling Auxiliary Feedwater flow in a more timely manner to maintain the RCS temperature closer to the normal operating bounds and thereby minimizing cooldown. These briefings will be completed by October 7, 1996.
This event will be covered in operator training to emphasize that several indicators, such as annunciators and VCT level, could have aided the operators in recognizing the realignment of the Charging/Safety Injection Pump suction. This training will be completed by October 7, 1996.
The plant system engineer will become more intrusive in coordinating switchyard activities including predictive and preventive maintenance. Switchyard maintenance has traditionally been scheduled and performed by Transmissions Department personnel. The scope of switchyard work during refueling outages will be established and integrated into the outage schedule by December 22, 1996.
NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (495)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (I) OOCKET LER NUMBER (6) PAGE (3)
SEOUENTULL YEAR NUMRER NUMBER Harris Nuclear Plant ~ Unit I 50 400 6 OF 6 96 - 008 00 TEXT pf nrav space fs abraded, uu zdditioad capet dl ffaC fo'e 3AQI (IT)
- 10. Mechanisms for identifying correct alignment of disconnect switches will be investigated. If identified, a suitable mechanism will,be installed during Refueling Outage No. 7 currently scheduled to commence in March 1997.
EIIS CODES:
Main Generator Output Breaker Disconnect: EL-DISC Normal Service Water Pump: <<G-P 6.8 KV Bus Under-voltage Lockout Relay: EA-RLY27 Emergency Diesel Generator: EK-DG Normal Service Water Pump Valve Control Relay: KE-RLY