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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 REGULATO INFORMATION DISTRIBUTION YSTEM (RIDS).ACCESSION NBR:9604300382 DOC.DATE: 96/04/24 NOTARIZED:
NO FACIL:50-400 Shearon Harris Nuclear Power.Plant, Unit 1, Carolina AUTH.NAME AUTHOR AFFILIATION ROWELLiL ST Carolina Power 6 Light Co.RECIP.NAME RECIPIENT AFFILIATION I DOCKET 05000400
SUBJECT:
LER 96-006-00:on 960325,separation of valve stem&di k f main F i W isolatIon valve caused valve to become inoperable.
g Is or Caused by mfg defect.Valve stem machined 6 procedures revised.W/960424 ltr.DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE: TITLE: 50.73/50.9 Licensee Event Report (LER)', Incident Rpt, etc.NOTES:Application for permit renewal filed.E 05000400 G RECIPIENT ID CODE/NAME PD2-1 PD INTERNAL: ACRS AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DSIR/EIB EXTERNAL: L ST LOBBY WARD NOAC MURPHY,G.A NRC PDR COPIES LTTR ENCL 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 RECIPIENT ID CODEtNAME LEgN/NP B FILE CENTER B NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB
'GN2 FILE 01 LITCO BRYCE,J H NOAC POORE,W.NUDOCS FULL TXT COPIES LTTR ENCL 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1~1 1 1 2 2 1 1 1 1 p E N NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE!CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5D-5(EXT.415-2083)TO ELIMINATE YOUR NAME FROM DISTRIBUTION IISTS FOR DOCUMENTS YOU DON'T NEED!FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 26 ENCL 26 Carolina Power 8 Light Company Harris Nuclear Plant PO Box 165 New Hill NC 27562 U.S.Nuclear Regulatory Commission ATTN: NRC Document Control Desk ApR p 4 1996 Washington, DC 20555 Serial: HNP-96-069
'0CFR50.73 SHEARON, HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO.50-400 LICENSE NO.NPF-63 LICENSEE EVENT REPORT 96-006-00 Gentlemen:
In accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted.
This report describes a separation of the valve stem and disk for a Main Feedwater Isolation Valve, resulting in a violation of the Technical Specification Action Statement.
Sincerely, LSR/lsr Enclosure~()Q$$3 c: Mr.J.B.Brady (NRC-HNP)Mr.S.D.Ebneter (NRC-RII)Mr.N.B.Le (NRC-PM/NRR)9tc04300382 960424 PDR ADOCK 05000400 S PDR State Road 113k New Hill NC NRC FORM 366 g.95)U.S.NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)(See reverse for required number of digits/characters for each block)APPROVED BY OMB No.3150-0104 EXPIRES 04/30/99 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THI MANDATORY INFORMATION COllECTION REOUESII SM HRS.REPORTED lESSONS LEARNED ARE INCORPORATED INTO THE UCENSUIG PROCESS AND FEO BACK TO INDUS'FRY.
FORWARD COMMENTS REGAROUIG BURDEN ESTIMATE TO THE INFORMATION AHO RECORDS MANAGEMENT BRANCH IT4(F33L US.HUClEAR REGU(ATORT COMMISSIOIL WASHU(GTON, OC 205550001, AND TO THE PAPERWORK REDUCTION PROJECT (3150.010(L Off ICE Of MANAGEMEN'r AND BUDGET, VIASHUIGTOH, OC 20503.FACIUTY NAME ll I Harris Nuclear Plant-Unit 1 DOCKET NUMBER (2I 50-400 PAGE (3)1 OF 3 TITLE (4I A separation of the valve stem and disk for Main Feedwater Isolation Valve 1FW-277 caused the valve to become inoperable and resulted in a violation of the Technical Specification Action Statement.
MONTH DAY YEAR EVENT DATE (5)LER NUMBER (6)SEQUENTIAL REVISION NUMBER NUMBER REPORT DATE (7)MONTH DAY YEAR FACILITY NAME OTHER FACILITIES INVOLVED (B)DOCKET NUMBER 05000 25 96 96-006-00 4 24 96 FACILITY NAME DOCKET NUMBER'5000 OPERATING MODE (9)POWER LEVEL (10)THIS REPORT IS SUBMITTED PUR 20.2201(b) 20.2203(a)(1) 20.2203(a)
(2)(i)20.2203(a)(2)(ii)20.2203(a)(2)(iii)20.2203(a)(2)(iv)
SUANT To THE REQUIREMENTS OF 10 CFR B: (Check one o 20.2203(a)
(2)(v)50.73(a)(2)(i) 50.73(a)(2)(ii)50.73(a)(2)(iii) 50.73(a)(2)(iv)20.2203(a)(3)(i)20.2203(a)(3)(ii) 20.2203(a)
(4)50.73(a)(2)(v) 50.73(a)(2)(vii) 50.36(c)(1) 50.36(c)(2) r moro)(11)50.73(a)(2)(viii)50.73(a)(2)(x) 73.71 OTHER Specify in Abstract below or in NRC Form 3BOA LICENSEE CONTACT FOR THIS LER Lewis S.Rowell-Project Engineer-Licensing/Regulatory Programs MPONENT FAILURE DES (12)TELEPHONE NUMBER Urcluda Area Coda((919)362-2287 CRIBED IN THIS REPORT (13)CAUSE SYSTEM COMPO NEIIT MANUFACTURER REPORTABI.E TD NPRDS CAUSE SYSTEM COL'IPONENT
'ANUFACTURER REPORTABLE TO NPRDS SJ ISV B350 SUPPLEMENTAL REPORT EXPECTED (14)YES (If yes, complete EXPECTED SUBMISSION DATE).No EXPECTED SUBMISSION DATE (15)MONTH DAY YEAR ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)(16)On February 15, 1996 the plant was operating in Mode 1 with Reactor Power at 100%.At approximately 0108, the Metal Impact Monitoring System (MIMS)for the"B" Steam Generator pegged high and simultaneously a momentary low nitrogen pressure alarm was received on the"B" Steam Generator Feedwater Isolation Valve (1FW-277).
On March 4, 1996, 1FW-277 was partially stroked in accordance with surveillance test OST-1018.On March 15, 1996 a flow reduction trend was noted on Main Feedwater preheat line flow data.At this point, plant personnel recognized that the February 15, 1996 MIMS and low nitrogen pressure alarms may have been related to this trend in flow reduction.
Troubleshooting was commenced.
On March 22, 1996 the plant was shutdown and valve 1FW-277 was stroked with personnel near the valve to monitor for characteristic sounds of valve stroking.Because the characteristic sounds were not heard, the valve was disassembled on March 25, 1996.Inspection revealed that the valve stem had fractured.
Metallurgical analysis revealed that the crack had originated at the small diameter of the backseat to stem transition and propogated by low cycle fatigue until the load was sufficient to cause the final tension overload failure.Further investigation showed that a manufacturing defect had allowed the disk of this gate valve to be pulled hard into the bonnet when opened, causing unacceptable bending loads in the stem.The replacement valve stem was machined ch that the valve disk will not contact the bonnet when the valve.opens.Additionally, the Corrective intenance procedure for Main Feedwater Isolation Valves will be revised to include a verification prior final reassembly that the disk is not striking/contacting the bonnet.
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NRC FORM 366A I4.951 LICENSEE EVENT REPORT (LERj TEXT CONTINUATION U.S.NUCLEAR REGULATORY COMMISSION FACILITY NAME 01 Harris Nuclear Plant~Unit 1 TEXT Pl eOrO OpOOO a rdrrOOOd, raO OddirrOOOl OOpOO Ol NR FOre (ITI OOCKET 50 400 LER NUMBER (6)YEAR SEOUENTIAL REVISION NUMBER NUIABER 96-006-00 PAGE IBI 2 OF 3 EVENT DESCRIPTION:
On February 15, 1996, the plant was operating in Mode 1 with Reactor Power at 100%.At approximately 0108, the Metal Impact Monitoring System (MIMS)for the"8" Steam Generator (SG)pegged high and simultaneously a momentary low nitrogen pressure alarm was received on the"8" SG Feedwater Isolation Valve (1FW-277)(EIIS Code SJ-ISV, Borg Warner, Valve Assembly-Gate, 16", 0 4350885-001, Hydraulic Operator).
On March 4, 1996 the valve was partially stroked in accordance with surveillance procedure OST-1018.On March 15, 1996, a flow reduction trend was noted on the"8" Main Feedwater line by the system engineer.At this point, plant personnel recognized that the February 15, 1996 MIMS and low nitrogen pressure alarms may have been related to this trend in flow reduction.
Troubleshooting was commenced.
This trend was confirmed by an increase in Preheater Bypass flow, increased opening of the Feedwater Regulating valve, and increased pressure upstream of the 1FW-277 valve.On March 22, 1996 the plant was shutdown for load sequencer inoperability (LER 96-002-003), and this valve was stroked with personnel near the valve listening for the characteristic loading up of the actuator hydraulic pump and the sound of the disk unwedging.
The absence of these characteristic sounds provided confirmation that the valve was not functioning properly.n March 25, 1996 the 1FW-277 valve was disassembled and inspection revealed that the valve stem had ractured.Metallurgical analysis revealed that the crack had originated at the small diameter of the backseat to stem transition and propogated by low cycle fatigue until the load was sufficient to cause the final tension overload failure.Unusual marking in the domed area inside the valve bonnet was noted.This indicated that the disk had firmly contacted the bonnet when opened instead of the stem backseat contacting the bonnet backseat area.This was confirmed by assembling the disk, a replacement stem, and the bonnet and noting the interference between the disk and bonnet.The bonnet backseat area inset was deeper than would be expected for the valve assembly.Based upon discussions with the valve manufacturer, it was determined that the actual inset of 0.406" was 0.181" deeper than the nominal inset dimension of 0.225".Thus, the stem had to travel approximately 3/16" farther than"nominal" to reach the backseat.The valve is designed to backseat when open.Valve 1FW-277 has an orientation of approximately 50 degrees from vertical which causes the disk to rest in the bottom of the lower guide body while stroking.This results in an offset between the disk centerline and the stem centerline of approximately I/4" and caused a bending moment on the lower stem, consistent with the crack initiation location.The loads, bending moment, and number of cycles on the valve stem are consistent with the low cycle fatigue symptoms observed on the failed stem.An engineering review determined that the valve would be incapable of performing its containment isolation function with the fractured stem.This condition had potentially existed since February 15, 1996.Therefore, the Technical Specification 3/4.6.3 Action Statement, requiring an inoperable valve to be restored to OPERABLE status or the affected penetration isolated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, or that the plant be placed in COLD SHUTDOWN within the following 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, was violated.This event is being reported per 10CFR50.73(a)(2)(i).
CAUSE: he root cause of the stem failure was a manufacturing defect which allowed the disk of this gate valve to be lied hard into the bonnet when opened, binding the disk to the stem and placing unanticipated bending loads in the stem.The effect of this failure was the inability of this valve to fully close and perform its design basis containment isolation function.
l$NRC FORM 366A l495)LICENSEE EVENT REPORT (LER)TEXT CONTINUATION US.NUCLEAR REGULATORY COMMISSION FACILITY NAME (I)Harris Nuclear Plant~Unit 1 DOCKET 50400 LER NUMBER I6)YEAR SEQUENTIAL NUMBER NUMBER 96-006-0.00 PAGE)3)3 OF 3 TEXT Pr pisrs sptss it ssFiisaf, siss stcam)itasl snpis pr)VRC Falsi 366iU I)T)SAFETY SIGNIFICANCE:
An engineering review was conducted of analyzed accident scenarios, assuming that the 1FW-277 valve would not be capable of performing its design basis containment isolation function.The review concluded that failure of the valve to close fully would not alter the conclusions of those accident scenarios since operator action or the system control logic would require closure of the Main Feedwater Regulating valve for feedwater and containment isolation.
Also, the safety-related check valve upstream of 1FW-277 would act as backup for containment isolation for those scenarios in which containment pressure is greater than upstream pressure.Additionally, based upon the probabilistic safety assessment, the unavailability of one or more main feedwater isolation valves is not safety-significant.
The potential consequences of valve failure are overfilling the affected steam generator and subsequent overcooling of the RCS.This could be mitigated by plant design features (tripping of the main feedwater pumps or automatic closure of the Feedwater regulating valves), or by operator intervention to control the main feedwater system.This event is judged to be nonsafety-significant.
The only other valves of this type at this facility are the other two MFIVs.Unlike 1FW-277, both of these valves have been disassembled since plant startup (1FW-159 in late 1994 and 1FW-217 in late 1995)with the bonnets inspected.
Personnel involved with the disassembly of those valves did not observe any contact marks as seen on 1FW-277.P PREVIOUS SIIVIILAR EVENTS: ere have been no similar events of component failures of Main Feedwater Isolation valves at the Harris Nuclear ant.CORRECTIVE ACTIONS COMPLETED:
The valve stem was replaced and the replacement stem"T Head" was machined such that the valve disk will not contact the bonnet when the valve is opened.CORRECTIVE ACTIONS PLANNED: The Corrective Maintenance procedure (CM-M0204) which provides instructions for disassembly, maintenance, inspection, and reassembly of the Main Feedwater Isolation Valves will be revised by August 31, 1996 to include verification prior to final valve reassembly that a valve disk does not strike/contact the bonnet.EIIS CODES: Main Feedwater Isolation Valve (MFIV)(SJ-ISV).