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Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER)
MONTHYEARML20216E5401999-09-0707 September 1999 Special Rept:On 990826,discovered That Meteorological Sys Upper Wind Speed Cup Set Broken,Causing Upper Wind Channel to Be Inoperable.Cup Set Replaced & Channel Restored to Operable Status on 990826 ML20210R1051999-08-0606 August 1999 Special Rept:On 990628,cathodic Protection Sys Was Declared Inoperable After Sys Did Not Pass Acceptance Criteria of Bimonthly Surveillance.Work Request 98085802 Was Initiated & Connections on Well Anode Were Cleaned or Replaced ML20206P2081998-12-31031 December 1998 Special Rept:On 981218,inoperability of Meteorological Monitoring Instrumentation Channels,Was Observed.Caused by Data Logger Overloading Circuit.Replaced & Repaired Temp Signal Processor ML20198B1341998-12-14014 December 1998 Revised Special Rept:On 980505,discovered That Certain Fire Barriers Appeared to Be Degraded.Caused by Removal of Firestop Damming Boards.Hourly Fire Watches Established in Affected Areas ML20196D4041998-11-19019 November 1998 Rev 1 to Special Rept:On 980618,determined That Method Used to Calibrate Wind Speed Instrumentation Loops of Meteorological Monitoring Instrumentation Sys Does Not Meet TS Definition for Channel Calibration.Procedure Revised ML20153B0531998-09-16016 September 1998 Special Rept:On 980817,errors in Implementation of Selected Licensee Commitment Testing Requirements on Fire Protection Sys Instruments,Was Discovered.Caused by Error in Interpretation of SLC Requirement.Will Revise Procedures ML20236M9151998-07-0707 July 1998 Special Rept:On 980611,determined That Required Firewatch Patrol Had Been Missed.Caused by Firewatch Being Performed on Wrong Unit Due to Human Error.Employee Was Verbally Counseled on Firewatches & Documentation Was Corrected ML20236G4451998-07-0101 July 1998 Special Rept:On 980618,declared Wind Speed Instrumentation Loops of Meteorological Monitoring Instrumentation Sys Inoperable.Caused by Failure to Meet TS Definition of Channel Calibr.Will Revise Selected Licensee Commitment ML20248K1431998-06-0202 June 1998 Special Rept:On 980505,discovered That Certain Fire Barriers Appeared to Be Degraded.Caused by Shrinkage of Foam & Improper Installation During Construction of Plant.Posted Fire Watches & Repaired Firestop F-AX-348-W-134 ML20247H5351998-04-12012 April 1998 Special Rept:On 980415,missed Insp of Fire Hose Caskets Was Discovered.Caused by Error in Transferring Info from One Procedure to Another.Planned Rev of Applicable Procedure to Include Gasket Insp at Appropriate Frequency ML20216B0211998-04-0606 April 1998 Special Rept:On 980325,determined That Loose Parts Monitoring Sys Being Inoperable for Greater than Thirty Days.Caused by Incorrect Testing.All Channels of Loose Parts Monitoring Sys Tested Utilizing Revised Test Method ML20217K9271998-03-26026 March 1998 Special Rept:On 971229,procedure Step for Closing Safety Injection Pump Cold Leg Injection Isolation Valve Was Inadvertently Skipped.Caused by Injection of Water Into RCS from Rwst.Simplified Procedures & Discussed Event ML20216D5641998-03-0505 March 1998 Special Rept:On 980204,discovered That Fire Detection Panel Was Apparently Not Communicating W/Several Local Fire Detectors.Caused by Faulty Computer Sys Cards.Replaced Four Computer Cards in Sys ML20202C4701998-02-0505 February 1998 Ro:On 971228:Unit 1 Loose Parts Monitoring Sys Channel 6 Was Declared Inoperable Due to Excessive Static on Channel. Caused by Loose Connection.Work Order Has Been Written to Pursue Repairs ML20138E6851997-04-24024 April 1997 Special Rept:On 970318,Unit 1 Loose Parts Monitoring Sys Channel 13 Was Declared Inoperable Due to Sporadic Electical Static.Channel Was Removed from Svc & Entered Into TS Action Item Logbook as Inoperable ML20149M7251997-01-20020 January 1997 Special Rept:On 961209,Unit 1 Loose Parts Monitoring (Lpm) Sys Channel 20 Declared Inoperable Due to No Signal Being Received from Field.Lpm Channel 20 & 22 Operable & Providing Monitoring Coverage for Primary Side of 1D S/G ML20134K4901996-11-0606 November 1996 Special Rept:On 961009,selective Licensee Commitment for Operability of Fire Protection Sprinkler Sys Not Maintained. Continuous Fire Watch Established within One H Following Identification of Incorrect Remedial Action ML20134H1331996-11-0404 November 1996 Special Rept:On 961004,Unit 1B DG Failed Due to Failure of Motor Operated Pot,Electronic & Mechanical Governor,Governor Droop Relay & Mechanical Binding of Fuel Rack Control Linkage.Dg Procedures Will Be Revised ML20113A1801996-06-17017 June 1996 Special Rept:On 960521,declared Detectors A01 for Zone 69 & A04 for Zone 60 Inoperable Because Detectors Effectively Isolated from Area in Intended Protection.Detectors Relocated,Tested & Declared Operable on 960524 ML20100H9801996-02-20020 February 1996 Special Rept:On 960111,Unit 1 Loose Parts Monitoring Channel 21 Declared Inoperable,Due to Spurious,Unexplainable Electronic Bursts.Work Request Initiated to Pursue Corrective Action ML20100H9751996-02-20020 February 1996 Special Rept:On 960111,Unit 2 Loose Parts Monitoring Sys Channel 7 Declared Inoperable,Due to pre-amp Bias Voltage Indicating Zero Volts Twice During Previous Seven Days.Work Request Written to Pursue Corrective Action ML20097F5011996-02-11011 February 1996 Special Rept:On 960102,Unit 2 Loose Parts Monitoring Sys Channel 17 Was Declared Inoperable.Two Other Channels Operable & Providing Coverage Against Loose Parts ML20096E7731996-01-12012 January 1996 Special Rept:On 951214,unit 2 DG Valid Failure Occurred. Caused by Fuel Line Fitting Backing Off from Cylinder Head Connection,Which Resulted in Fuel Oil Leakage.Dg Successfully Started,Run & Declared Operable on 951215 ML20096A8761995-12-18018 December 1995 Special Rept:On 951120,during Periodic Surveillance Testing, Lpms Channel 5 Declared Inoperable.Caused by Erratic Preamp Bias Voltage Indications.Work Request 95048483 Initiated to Perform Corrective Maint During Unit 1 Cycle 9 ML20094Q5811995-11-13013 November 1995 Special Rept:On 951014,auxiliary Bldg Filtered Exhaust Sys Pump Room Heater Declared Inoperable Due to Blown Fuse & Not Restored to Operable Status within 7 Days Per Ts. Technical Investigation Will Be Performed ML20094B8291995-10-25025 October 1995 Special Rept:On 950919,loose Parts Monitoring Sys Channel 1 Declared Inoperable Due to Erratic Preamp Bias Indication. Work Request Written to Investigate & Repair Channel ML20098A4641995-09-19019 September 1995 Special Rept:On 950817,Unit 2 Lpms Channel 12 Was Declared Inoperable Due to Channel Sensor Failing Acceptance Criteria During Performance of PT/O/A4600/03 ML20092G6041995-09-14014 September 1995 Special Rept:On 950815,CNS Unit 1 DG 1A Invalid Failure Occurred Due to Main Bearing High Temp Trip Signal.Caused by Failed Splice Installed in Circuit for RTD 1LDRD5630.New RTD Installed in Main Bearing 5 ML20086H1401995-07-12012 July 1995 Special Rept:On 950615,Channel 4 Was Declared Inoperable Due to Noise Uncharacteristic of Healthy Channel Detected Via Vibration & Loose Parts Monitoring Sys.Corrective Maint Will Be Performed During 1EOC9 Outage ML20086H1431995-07-11011 July 1995 Special Rept:On 950608,Channel 13 Was Declared Inoperable. Trending of Bias Voltage & Background RMS Evaluated to Conclude Channel Was Experiencing Periodic Failures. Corrective Maint Will Be Performed During 1EOC9 Outage ML20086C6441995-06-29029 June 1995 Special Rept:On 950523,Unit 1 Train a Fuel Handling Ventilation Filter Heaters Declared Inoperable.Evaluation Done to Determine Fault ML20085M4061995-06-20020 June 1995 Special Rept:On 950501,lower Rv Tube 4 Was Declared Inoperable ML20084N7271995-05-25025 May 1995 Special Rept:On 950425,valid Failure of DG 1A Occurred. Caused by Jacket Water Thermostatic Control Valve Sticking in Position Which Reduced Engine Cw Flow Through Heat Exchanger.Thermostatic Cv Internals Removed & Replaced ML20082L2711995-04-17017 April 1995 Special Rept:On 950308,Unit 2 Cathodic Protection Sys Was Declared Inoperable & Remained Inoperable Greater than 10 Days ML20081D4851995-03-13013 March 1995 Special Rept:On 950211,actuation of PORV 1NC32B Occurred. Procedure OP/1(2)/A/6100/02 Revised to Require More Emphasis on Monitoring Pressure Indication During Sensitive Evolutions ML20080Q8701995-03-0202 March 1995 Special Rept:On 950202,Unit 1 DG 1B Invalid Failure Due to Overcurrent Breaker Trip During Governor Troubleshooting ML20149H7821994-12-20020 December 1994 Special Rept:On 941129,discovered That Selective Licensee Commitment (SLC) for Visual Insp of Fire Rated Assemblies Exceeded Due to Misinterpretation of Requirements of SLC 16.9-5.Fire Barriers Visually Inspected ML20078R0021994-12-12012 December 1994 Special Rept:On 941103,Channel 3 (Upper Rv a) Declared Inoperable.Caused by Channel Sensor Failure of Acceptance Criteria During Performance of PT/0/A/4600/03.Repair Planned for End of 2EOC7 Outage Due to Containment Entry Required ML20078K7361994-11-17017 November 1994 Special Rept on 941021,DG 1A Invalid Failure Occurred Due to Main Bearing High Temp Trip.Operability Performance Test Successfully Completed & Engine Declared Operable on 941022 ML20149G8041994-11-0101 November 1994 Special Rept:On 940922,CNS,Unit 2 Cathodic Protection Sys Declared Inoperable & Remained Inoperable for Greater than 10 Days.Wo 94080948-01 Initiated to Replace Prepackaged Anode Well 1.WO Scheduled for 941114 ML20076F3191994-10-0404 October 1994 Special Rept:On 940908,valid Failure of D/G 1A Occurred Due to Air Start Valve Sticking Open.Maint Procedure MP/0/A/7650/99 Revised,New Air Roll Criteria Developed & Sixteen Starting Air Valves Replaced ML20072P4251994-08-23023 August 1994 Ro:On 940719,channel 9 (S/G a Channel 2) Declared Inoperable.Work Request Was Generated to Repair Channel During Future Outage of Sufficient Length Since Containment Entry Required for Work ML20072E5961994-08-15015 August 1994 Special Rept:On 940715,inoperability of Unit 2 Vibration & Loose Parts Monitoring System Channel 4 & 6 Occurred.Caused by Leds Not Lighting During Performance of PT/0/B/4600/03. Work Orders 94051250-01 & 94051251-01 Initiated ML20071N8511994-07-28028 July 1994 Special Rept:On 940711,main Steam Relief Valve Exhaust Monitors Declared Inoperable Due to Engineering Calculation Concerns.Engineering Calculation CNC-1229.00-00-0047 re-performed Using EPA-400 Methodology ML20071N7441994-07-28028 July 1994 Special Rept:On 940711,delta-t Channel on Chart Recorder Found to Be out-of-tolerance Due to Drifting of Analog to Digital (A/D) Converter Card.A/D Card Replaced & delta-t Channel Chart Recorder Declared Operable ML20070K0191994-07-18018 July 1994 Special Rept:On 940630,re Inoperability of Main Steam Line Radiation Monitor 2EMF12.Work Request 94026262 Generated to Reattach 2EMF12 to Main Steamline.Work Request Completed on 940701 ML20069H0861994-05-31031 May 1994 Special Rept:On 940501,Unit 2 DG 2A Invalid Failure Occurred Due to Right Bank Turbocharger Vibration Trip.Based on Cooper-Enterprise Recommendations,Procedure Changes Made to Calibr Procedures for All Four DGs ML20065K5011994-04-13013 April 1994 Special Rept:On 940314,invalid Failure of Diesel Generator 1B Occurred Due to Output Tripping During Calibration of Electronic Governor.Dg 1B Started Successfully on 940315 & Declared Operable ML20064G2911994-03-15015 March 1994 Special Rept:On 940203,SG Channels 9 & 11 Declared Inoperable.Channels Failed to Meet Band Limited RMS Acceptance Criteria During Performance of 18 Month Channel Calibr Test.Work Request Written to Repair Channels ML20064G2771994-03-0707 March 1994 Special Rept:On 940125,Channels 6,7 & 10 Were Declared Inoperable.Channels Failed to Meet Acceptance Criteria During Performance of 18 Month Channel Calibr Test.Work Request Written to Repair Channels 1999-09-07
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20212J1891999-10-0101 October 1999 Safety Evaluation Supporting Exemption from 10CFR54.17(c)re Schedule to Apply for Renewed Operating Licenses ML20212A6271999-09-30030 September 1999 Rev 0 to WCAP-15243, Anaylsis of Capsule V & Capsule Y Dosimeters from Duke Energy Catawba Unit 2 Reactor Vessel Radiation Surveillance Program ML20217H0201999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Catawba Nuclear Station,Units 1 & 2 05000414/LER-1999-004-01, :on 980906,error During Tagout Caused de-energization of Vital Bus & Actuation of Ltop.Caused by Inadequate Work Practices.Individuals Involved Were Counseled1999-09-27027 September 1999
- on 980906,error During Tagout Caused de-energization of Vital Bus & Actuation of Ltop.Caused by Inadequate Work Practices.Individuals Involved Were Counseled
05000413/LER-1999-015, :on 990616,discovered That Auxiliary Bldg Filtered Ventilation Exhaust Sys Was Inoperable.Caused by Improperly Positioned Vortex Damper.Damper Was Repositioned Correctly & Sys Was Retested Successfully1999-09-27027 September 1999
- on 990616,discovered That Auxiliary Bldg Filtered Ventilation Exhaust Sys Was Inoperable.Caused by Improperly Positioned Vortex Damper.Damper Was Repositioned Correctly & Sys Was Retested Successfully
ML20212G2511999-09-22022 September 1999 Safety Evaluation Supporting Amends 180 & 172 to Licenses NPF-35 & NPF-52,respectively 05000413/LER-1999-008, :on 990610,operations Prohibited by TS 3.5.2, Was Violated.Caused by Inoperable Centrifugal Charging Pump. Operators Swapped to CCP 1A & Sys Parameters Were Returned to Normal.With1999-09-21021 September 1999
- on 990610,operations Prohibited by TS 3.5.2, Was Violated.Caused by Inoperable Centrifugal Charging Pump. Operators Swapped to CCP 1A & Sys Parameters Were Returned to Normal.With
05000414/LER-1999-005-02, :on 990727,missed Emergency DG TS Surveillance Concerning Verification of Availability of Offsite Power Sources,Was Declared.Caused by Defective Procedure.Revised Affected Procedure1999-09-20020 September 1999
- on 990727,missed Emergency DG TS Surveillance Concerning Verification of Availability of Offsite Power Sources,Was Declared.Caused by Defective Procedure.Revised Affected Procedure
05000413/LER-1999-009, :on 990518,inoperability of Containment Valve Injection Water Sys Valve in Excess of TS Limits Was Noted. Caused by Inadequate Retest Following Surveillance Test Failure.Valve Was Retested & Returned to Service1999-09-15015 September 1999
- on 990518,inoperability of Containment Valve Injection Water Sys Valve in Excess of TS Limits Was Noted. Caused by Inadequate Retest Following Surveillance Test Failure.Valve Was Retested & Returned to Service
ML20216E5401999-09-0707 September 1999 Special Rept:On 990826,discovered That Meteorological Sys Upper Wind Speed Cup Set Broken,Causing Upper Wind Channel to Be Inoperable.Cup Set Replaced & Channel Restored to Operable Status on 990826 05000413/LER-1999-014, :on 990816,missed Surveillances & Operation Prohibited by TS Was Noted.Caused by Defective Procedures or Programs Inappropriate TS Requirements.Affected Procedures/ Programs Were Revised & Testing Was Performed1999-09-0101 September 1999
- on 990816,missed Surveillances & Operation Prohibited by TS Was Noted.Caused by Defective Procedures or Programs Inappropriate TS Requirements.Affected Procedures/ Programs Were Revised & Testing Was Performed
05000414/LER-1999-004, :on 990616,CIV 2NM-221A Was Returned to Svc Without Testing,As Required by TS 3.6.3.Caused by Programmatic Deficiency.Test Procedure Has Been Revised & Subject Valve Was Successfully Tested & Returned to Svc1999-09-0101 September 1999
- on 990616,CIV 2NM-221A Was Returned to Svc Without Testing,As Required by TS 3.6.3.Caused by Programmatic Deficiency.Test Procedure Has Been Revised & Subject Valve Was Successfully Tested & Returned to Svc
ML20212B4711999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Catawba Nuclear Station,Units 1 & 2 05000414/LER-1999-003, :on 990612,unplanned Actuation of ESFAS Occurred Due to a SG High Level.Caused by Inadequate Procedural Guidance.Msiv 2SM-7 Was Closed & SG 2A Level Was Returned to Normal1999-08-31031 August 1999
- on 990612,unplanned Actuation of ESFAS Occurred Due to a SG High Level.Caused by Inadequate Procedural Guidance.Msiv 2SM-7 Was Closed & SG 2A Level Was Returned to Normal
ML20211B1281999-08-31031 August 1999 Dynamic Rod Worth Measurement Using Casmo/Simulate ML20217H0321999-08-31031 August 1999 Revised Monthly Operating Rept for Aug 1999 for Catawba Nuclear Station,Units 1 & 2 05000413/LER-1999-012, :on 990727,adverse Sys Interaction Between Annulus Ventilation Sys & Auxiliary Building Ventilation Sys Was Discovered.Caused by Inadequate Design.Compensatory Actions Developed & Implemented.With1999-08-26026 August 1999
- on 990727,adverse Sys Interaction Between Annulus Ventilation Sys & Auxiliary Building Ventilation Sys Was Discovered.Caused by Inadequate Design.Compensatory Actions Developed & Implemented.With
ML20211A9791999-08-20020 August 1999 Safety Evaluation Granting Licensee Request for Approval of Proposed Relief from Volumetric Exam Requirements of ASME B&PV Code,Section Xi,For Plant,Unit 2 ML20211C1291999-08-17017 August 1999 ISI Rept Unit 1 Catawba 1999 RFO 11 ML20211F3441999-08-17017 August 1999 Updated non-proprietary Page 2-4 of TR DPC-NE-2009 ML20210U8341999-08-13013 August 1999 Safety Evaluation Supporting Amends 179 & 171 to Licenses NPF-35 & NPF-52,respectively ML20210R1051999-08-0606 August 1999 Special Rept:On 990628,cathodic Protection Sys Was Declared Inoperable After Sys Did Not Pass Acceptance Criteria of Bimonthly Surveillance.Work Request 98085802 Was Initiated & Connections on Well Anode Were Cleaned or Replaced ML20212B4871999-07-31031 July 1999 Revised Monthly Operating Rept for July 1999 for Catawba Nuclear Station,Units 1 & 2 ML20210S2891999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Catawba Nuclear Station,Units 1 & 2 05000413/LER-1999-009, :on 990518,inoperability of Containment Valve Injection Water Sys Valve Was Noted in Excess of TS Limits. Caused by Inadequate Testing Following Surveillance Test Failure.Valve Was Retested & Restored to Service1999-07-19019 July 1999
- on 990518,inoperability of Containment Valve Injection Water Sys Valve Was Noted in Excess of TS Limits. Caused by Inadequate Testing Following Surveillance Test Failure.Valve Was Retested & Restored to Service
05000414/LER-1999-004-02, :on 990610,violation of TS 3.6.3 Was Noted Due to CIV 2NM-221A Being Returned to Service Without Testing. Caused by Procedure Deficiency.Civ 2NM-221A Was Tested & Returned to Operable Status1999-07-15015 July 1999
- on 990610,violation of TS 3.6.3 Was Noted Due to CIV 2NM-221A Being Returned to Service Without Testing. Caused by Procedure Deficiency.Civ 2NM-221A Was Tested & Returned to Operable Status
ML20209E4361999-07-0909 July 1999 SER Agreeing with Licensee General Interpretation of TS LCO 3.0.6,but Finds No Technical Basis or Guidance That Snubbers Could Be Treated as Exception to General Interpretation 05000414/LER-1999-003-02, :on 990612,unplanned Actuation of Esfa Sys Due to a SG High Level Was Noted.Caused by Inadequate Procedural Guidance.Long Term Corrective Actions to Prevent Recurrence of Event Are Being Developed1999-07-0808 July 1999
- on 990612,unplanned Actuation of Esfa Sys Due to a SG High Level Was Noted.Caused by Inadequate Procedural Guidance.Long Term Corrective Actions to Prevent Recurrence of Event Are Being Developed
ML20196K6631999-07-0707 July 1999 Safety Evaluation Supporting Licensee 990520 Position Re Inoperable Snubbers ML20209H4501999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Catawba Nuclear Station,Units 1 & 2 ML20210S2951999-06-30030 June 1999 Revised Monthly Operating Rept for June 1999 for Catawba Nuclear Station,Units 1 & 2 05000414/LER-1999-002-03, :on 990504,plant Was Forced to Shutdown as Result of Flow Restriction Caused by Corrosion of Afs Assured Suction Source Piping Due to Inadequate Testing. Affected Piping Was Cleaned & Flow Tested1999-06-0303 June 1999
- on 990504,plant Was Forced to Shutdown as Result of Flow Restriction Caused by Corrosion of Afs Assured Suction Source Piping Due to Inadequate Testing. Affected Piping Was Cleaned & Flow Tested
ML20209H4561999-05-31031 May 1999 Revised Monthly Operating Rept for May 1999 for Catawba Nuclear Station,Units 1 & 2 ML20196A0001999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Catawba Nuclear Station,Units 1 & 2 ML20196L1881999-05-31031 May 1999 Non-proprietary Rev 1 to DPC-NE-3004, Mass & Energy Release & Containment Response Methodology ML20206T4771999-05-31031 May 1999 Rev 3 to UFSAR Chapter 15 Sys Transient Analysis Methodology ML20206P5201999-05-14014 May 1999 Safety Evaluation Accepting GL 96-05, Periodic Verification of Design-Basis Capability of Safety-Related Motor-Operated Valves ML20206N8391999-05-0404 May 1999 Rev 16 to CNEI-0400-24, Catawba Unit 1 Cycle 12 Colr ML20196A0041999-04-30030 April 1999 Revised Monthly Operating Repts for Apr 1999 for Catawba Nuclear Station,Units 1 & 2 ML20206R1811999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Catawba Nuclear Station,Units 1 & 2 ML20206N8261999-04-22022 April 1999 Rev 15 to CNEI-0400-24, Catawba Unit 1 Cycle 12 Colr. Page 145 of 270 of Incoming Submittal Not Included ML20205S5551999-04-21021 April 1999 Safety Evaluation Accepting Response to GL 96-06, Assurance of Equipment Operability & Containment Integrity During Design Basis Accident Conditions 05000413/LER-1999-004, :on 990310,operation Prohibited by TSs Was Noted.Caused by Incorrect TS Requirements for Cravs & Auxiliary Bldg Filtered Ventilation Exhaust Sys Actuation Instrumentation.Submitted Lar.With1999-04-12012 April 1999
- on 990310,operation Prohibited by TSs Was Noted.Caused by Incorrect TS Requirements for Cravs & Auxiliary Bldg Filtered Ventilation Exhaust Sys Actuation Instrumentation.Submitted Lar.With
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 ML20205N3651999-04-12012 April 1999 Safety Evaluation Accepting IPE of External Events Submittal ML20205N2381999-04-0909 April 1999 Safety Evaluation Supporting Amends 178 & 170 to Licenses NPF-35 & NPF-52,respectively ML20205N2121999-04-0808 April 1999 Safety Evaluation Supporting Amends 177 & 169 to Licenses NPF-35 & NPF-52,respectively ML20206R1931999-03-31031 March 1999 Revised Monthly Operating Repts for Apr 1999 for Catawba Nuclear Station,Units 1 & 2 ML20205P9521999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Catawba Nuclear Station,Units 1 & 2 ML20205B3101999-03-26026 March 1999 Safety Evaluation Supporting Amends 176 & 168 to Licenses NPF-35 & NPF-52,respectively 1999-09-07
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Duke nnver Company D. L Rens Cataufm huclear Generchon bepartment Vice hesident 4%) Concord kvad (803kU12205 Oflice York. SC 29745 (803}8313126 Fax DUKEPOWER October 4,1994 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555
Subject:
Catawba Nuclear Station, Unit 2 Docket No. 50-413 Special Report Valid Failure of Diesel Generator (D/G) l A Pursuant to Catawba Technical Specification 4.8.1.1.3 and 6.9.2, please find attached a Special Report concerning the valid failure of D/G 1A which occurred on September 8,1994.
Very tmly yours, D. L. Rehn DT/
Attachment xc: Mr. S. D. Ebneter Regional Administrator, Region Il Mr. Robert E. Martin, Project Manager Mr. R. J. Freudenberger
'NRC Resident Inspector Catawba Nuclear Station 9410170044 941004
'DR ADOCK 05000412 eda
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4 U. 'S. ' Nuclear Regulatory Commission October 4,1994 Page 2 bxc: Z. L. Taylor R. A. Kayler NSRB Staff A. V. Carr J. E. Snyder J. E. Burchfield NCMPA-1 SREC PMPA NCEMC ELL-EC050 Group File: CN-801.01 Master File: CN-801.01 f
i U. 'S. Nuclear Regulatory Commission October 4,1994 Page 3 SPECIAL REPORT CATAWBA NUCLEAR STATION DIESEL GENERATOR 1 A VALID FAILURE DUE TO AIR START VALVE STICKING OPEN A valid failure of Diesel Generator I A (DG 1 A) occurred on 9/8/94 at 0920 hours0.0106 days <br />0.256 hours <br />0.00152 weeks <br />3.5006e-4 months <br /> due to an air start valve sticking open. The failure was caused by debris in the valve piston cap assembly that caused the valve to stick open which prevented the engine from reaching the required speed for combustion on the failed start attempt. DG 1 A was being run forits required monthly operability test when the failure occurred (start # 1021). There have been 2 valid failures (VF) in the last 20 and 100 start attempts. The 1 A DG is now on an accelerated weekly test frequency. The 1 A DG was successfully started, run, and declared operable on 9/11/94 at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br /> (Stan # 1026). The DG was unavailable for 37.42 hrs due to the failure.
The Unit l A Diesel Generator failed to start during the monthly run at 0920 hrs on 9/08/94.
The start was an emergency start; therefore, jumpers were placed by IAE to provide the emergency start signal. When the signal was initiated the air start solenoid valves opened but the engine did not start.
Background Information The l A Diesel Generator was being run per the required monthly operability procedure PT/1/A/4350/02A, on 9/8/94, when the engine failed to start due to an air start valve sticking open. Refer to the Operability Evaluation for this PIP for the root cause determination.
The starting air system for the diesel engines is comprised of two starting air tanks that are maintained at 250 psig, four starting air solenoid valves, two air start distributors, and an air start valve in each cylinder (16 total). On an engine start signal the solenoid valves get a signal to open and pressurize the starting air header. Air is also admitted to the cam driven air start distributor. The distributor sends a 60 psi pilot signal to the individual air cylinder start valves to cause the valves to open and allow air to enter the respective cylinder from the air header in the correct firing order. As discussed in the Operability Evaluation for this PIP, the root cause for the failure was that one of the air start valves stuck open during the start attempt.
d U. S. Nuclear Regulatory Commission October 4,1994 Page 4 The purpose of the starting air valves is to allow air from the starting air header to enter the cylinder when required and prevent the air from entering when not required. The valves get the signal to open from the air distributor. When the open signalis present, pressurized air from the header flows directly to the cylinder causing the engine to rotate. If fuel oil is present, the engine will fire during the rotation and thereby start and run under its own compression. With an air start valve stuck open, the engine will not rotate or rotate slower than required for combustion to occur but yet bleed the starting air pressure down to the 150 psig lockout setpoint.
With a starting air valve stuck open, when air is admitted on the start signal the cylinder with the stuck open valve will oppose the motion of the opposite cylinder resulting in the engine rocking instead of turning or rotating slower than required for engine combustion. This occurs as the cylinder with the stuck valve is going from bottom to top dead center on the compression stroke it will have to overcome starting air pressure flowing through the valve.
The opposing cylinder that is going from top to bottom dead center will end up having to overcome the force of the cylinder with the stuck valve, therefore the engine will either not roll or roll slower than required for engine combustion. During this condition the starting air tanks will drain through the cylinders and out through the intake / exhaust headers.
Following the start failure, the engine was rolled on air four times prior to the following successful start. During the air rolls, the engine was determined not to have a mechanical binding or fuel pump pinblem. The engine was successfully started and loaded at 1403 on 9/8/94 (start # 1022).
Per the engine manufacturer a stuck starting air cylinder valve can correct itself on subsequent engine rolls. Therefore, on the engine air rolls prior to the successful engine start, the stuck open starting air valve reseated thus allowing the engine to start.
EVALUATION i
i The starting air valves on the 1 A DG were removed and inspected by the engine j
manufacturer representative. His inspection revealed debris which could impede valve movement thereby causing the valve to stick open. Based on the data we provided and his observations of the air start valves, in his opinion it was highly probable that the 1 A DG failure was due to an air start valve sticking in the open position.
j U. S. Nuclear Regulatory Commission October 4,1994 Page 5 The 1 A DG was successfully started four times prior to the operability run. After inspection of the sixteen air start valves, it was determined that the use of NEO Lube 2 is not required on the air tubing fitting. The lubricant tends to build up in the valve and can lead to valve binding. Maintenance Procedure MP/0/A/7650/99 has been revised to reflect this information. Also, the piston assembly for the valves are going to be replaced with the latest model revision which includes a new material and dimension. The material will prevent the possibility of thermal binding and the dimension will increase the clearance between the piston and cap assembly. The pistons will be replaced on all the DGs. Furthermore, the air start valves on all four DGs have been tested per an air pop test and verified to be working properly.
Prior to the start failure, Operation noticed that the air roll did not sound normal. It was an inconsistent air roll and did not come to a smooth stop. This is the characterization of one of the air start valves being stuck open because as stated above the stuck open valve will oppose engine rotation. Afler discussion with the personnel present for the air rolls on the l A DG following the previous successful start attempt, they noticed no problems with these air rolls. The engine rolled normally and canic to a smooth stop. Therefore, the air start valve stuck open on the air rolljust before the start failure. Therefore, a new air roll criteria has been developed and incorporated in the operating procedures to ensure air start valve performance will be detected during engine air rolls.
The sixteen starting air valves have been replaced and the new valves verified to operate.
The engine was been successfully started three times with the new starting air valves prior to declaring the engine operable. The air start valves on the remaining DGs have also been verified to be operating normally. As stated above, all the valves will be upgraded with the new piston assembly.
The 1 A DG valid failure, was due to debris in the air start valves from the rebuild process which was compounded by not having the latest valve revision installed. The valves that are currently installed are within the required tolerances but are on the lower end. This failure will be prevented from occurring in the future by procedure enhancements and valve upgrades.
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