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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML17241A4891999-10-0707 October 1999 LER 99-004-00:on 990912,noted That MSSV Surveillance Was Outside of TS Requirements.Caused by Setpoint Drift.Subject MSSVs Are Being Refurbished & Retested Prior to Unit Startup from SL1-16 Refueling Outage.With 991007 Ltr ML17241A4111999-07-16016 July 1999 LER 99-007-00:on 990610,unplanned Cooldown Transient Occurred Due to Personnel Error.Trained & Briefed Personnel & Revised Procedures.With 990716 Ltr ML17241A4031999-07-0606 July 1999 LER 99-006-00:on 990605,sub-critical Reactor Trip Occurred Due to Inadvertent MSIV Opening.Caused by Personnel Error. Provided Operation Supervision Instruction to Operating Crews,Stand Down Meetings & Operator Aids.With 990706 Ltr ML17241A4041999-07-0606 July 1999 LER 99-005-00:on 990604,CEA Drop Resulted in Manual Reactor Trip.Caused by Procedural Inadequacies.Procedure Changes Are Planned to Correct Lack of Procedural Guidance for CEA Subgroup Power Switch Replacement.With 990706 Ltr ML17241A3941999-06-30030 June 1999 LER 99-004-01:on 990415,as Found Cycle 10 Psv Setpoints Were Outside TS Limits.Caused by Manufacturing Process Defect. All Three Psvs Were Replaced with pre-tested Valves During Cycle 11 Refueling Outage.With 990630 Ltr ML17241A3551999-06-0404 June 1999 LER 99-002-00:on 990505,both Trains of Safety Injection Actuation Were Blocked During Surveillance.Caused by Procedure Error.Procedure Revised.With 990604 Ltr ML17241A3321999-05-17017 May 1999 LER 99-004-00:on 990415,determined That as Found Cycle 10 Psv Setpoints Outside TS Limits.Root Cause Under Investigation.Psvs Replaced with pe-tested Valves During Cycle 11 ML17241A3271999-05-0606 May 1999 LER 99-003-00:on 990406,ECCS Suction Header Leak Resulted in Both ECCS Trains Being Inoperable & Entry Into TS 3.0.3. Caused by Chloride Induced OD Stress Corrosion Cracking of Piping.Made Code Repairs & Coated Piping.With 990506 Ltr ML17229B0791999-04-0707 April 1999 LER 99-001-00:on 990309,discovered Inadequate Design & IST SRs for Iodine Removal Sys (Irs).Caused by Original Design Inadequacies & Personnel Error.Naoh Tank Vent Valve V07233 Was Tagged Open.With 990407 Ltr ML17229B0801999-04-0707 April 1999 LER 99-002-00:on 990311,SG ECT Error Caused Operation with Condition Prohibited by Ts.Caused by Deficiencies in Data Analysis Guideline Instructions.Licensee Will Change Data Analysis Guidelines for Lead Analysts.With 990407 Ltr ML17229B0541999-03-10010 March 1999 LER 99-001-00:on 990211,inadequate TS SRs for SIT & SDC Isolation Valves Were Noted.Caused by Failure to Correctly Implement TS Srs.Submitted LAR to Align Required TS SR with Design Bases Requirements Being Verified.With 990310 Ltr ML17229A9901999-01-20020 January 1999 LER 98-009-00:on 981223,noted That Facility Operated Outside of Design Basis.Caused by non-conservative MSLB Analysis Inputs.Will Review SR Component Differences Between Units & Will re-baseline LTOP Analysis.With 990120 Ltr ML17229A9821999-01-0404 January 1999 LER 98-010-00:on 981207,RCS Boron Sample Frequency Required by Ts,Was Exceeded by Twelve Minutes.Caused by Personnel Error.Equipment Clearance Order Was Lifted to Draw Required Sample & Operations Procedure Was Changed.With 990104 Ltr ML17229A9611998-12-22022 December 1998 LER 97-002-01:on 981204,containment Sump Debris Screen Was Not IAW Design.Caused by Inadequate C/As for Sump Screen Anamolies.All Identified Sump Screen Deficiencies Were Dispositioned &/Or Repaired.With 981222 Ltr ML17229A9561998-12-15015 December 1998 LER 98-008-00:on 981118,missed TS SG U Tube Insp.Caused by Encoding Errors While Using Remote Positioning Fixtures.All SG Tube Surveyed.With 981215 Ltr ML17229A9301998-11-25025 November 1998 LER 98-005-01:on 980807,discovered That New MOV Methodology Caused Past PORV Block Valve Operability Problem.Caused by Inadequacies in Original Vendor MOV Methodology.Planned Valve Mods Will Be Implemented During Cycle 11 1998 Outage ML17229A9021998-11-0404 November 1998 LER 98-008-00:on 981008,inadequate Reactor Protection Sys Trip Bypass TS Was Noted.Caused by Poorly Worded Ts. Submitted LAR to Clarify Power Requirements for High Rate of Power Trips.With 981104 Ltr ML17229A8771998-10-14014 October 1998 LER 98-006-00:on 980918,inadvertent Afas Actuation Was Noted.Caused by Degradation of Multiple Afas Power Supplies. Replaced Afas Power Supplies & Revised Procedures.With 981014 Ltr ML17229A8761998-10-14014 October 1998 LER 98-007-00:on 980918,identified Discrepancies Between Fire Protection Design Requirements & Field Conditions. Caused by Inadequate Translation & Implementation of Fire Protection Requirements.Procedures Revised.With 981014 Ltr ML17229A8511998-09-0202 September 1998 LER 98-005-00:on 980807,discovered That PORV Margins Were Insufficient to Accommodate Addl Conservatism.Caused by Inadequacies in Original Vendor MOV Methodology.Will Implement Planned Valve Actuator mods.W/980902 Ltr ML17229A8201998-07-29029 July 1998 LER 98-007-00:on 980630,inadequate Procedure May Have Resulted in SBO Recovery Complications.Caused by Inadequate Procedures.Attached Caution Tags to Appropriate Control switches.W/980729 Ltr ML17229A7411998-05-28028 May 1998 LER 98-004-00:on 980430,discovered Waste Gas Decay Tank Operation W/O Available Oxygen Analyzers,Which Is Prohibited by Ts.Caused by Inadequate Licensee Review of License Amend. Oxygen Analyzer recalibrated.W/980528 Ltr ML17229A7381998-05-21021 May 1998 LER 98-006-00:on 980421,missed EDG Fuel Oil Sample Surveillance Was Noted.Caused by Personnel Error.Revised Fuel Oil Sampling Service Purchase Order & Revised Site procedure.W/980521 Ltr ML17229A7011998-04-27027 April 1998 LER 98-003-00:on 980326,discovered Containment Pressure Instrumentation Design Single Failure Vulnerability.Caused by Inadequate Design by Personnel Error.Removed RPS & ESFAS Containment Pressure Bypass Keys immediately.W/980427 Ltr ML17229A6761998-04-0202 April 1998 LER 98-005-00:on 980305,identified Two Conditions That Were Outside App R Design Bases.Caused by Design Oversight During Development of Original App R Safe SD Design.Established 30 Minute Roving Fire Watches & Provided training.W/980402 Ltr ML17229A6731998-03-26026 March 1998 LER 98-002-00:on 980224,radiation Monitor Surveillance Inadequacies Led to Operating of Facility Prohibited by Tss. Caused by Congnitive Personnel Error.Permanent Procedure Changes Were implemented.W/980326 Ltr ML17229A6551998-03-0505 March 1998 LER 98-001-00:on 980206,high/low Pressure Shutdown Cooling Interface Was Noted Outside App R Design Bases.Caused by Personnel Error.Addl Guidance Was Provided to Engineering Dept personnel.W/980305 Ltr ML17229A6281998-02-19019 February 1998 LER 98-004-00:on 980121,emergency Lighting Outside App R Design Bases Occurred.Caused by Congnitive Personnel Error During Translation of App R Section Iii.Procedures Onop 1 & 2 ONP-100.01 Were Issued for Use on 980206.W/980219 Ltr ML17229A6211998-02-0909 February 1998 LER 98-003-00:on 980110,manual Rt Due to DEH Leak at Turbine Test Block Was Noted.Caused by o-ring Extrusion.Shortened Bolts by About 0.125 & Reinstalled at Correct Torque values.W/980209 Ltr ML17229A6191998-02-0404 February 1998 LER 98-002-00:on 980105,CIS Bistable in Bypass Resulted in Condition Prohibited by Tss.Caused by Personnel Error. Radiation Monitor Was Restored to service.W/980204 Ltr ML17229A6161998-02-0303 February 1998 LER 98-001-00:on 980104,inadvertent RPS Actuation Occurred Due to Personnel Error.Caused by Procedural Inadequacies & Inadequate self-checking by Licensed Utility Personnel. Placards Have Been Placed in CRs.W/980203 Ltr ML17229A6051998-01-27027 January 1998 LER 97-010-01:on 971027,inadvertent Core Alteration Prohibited by TSs Were Noted Due to Stuck Cea.Caused by Personnel Error.Cea #24 Was Dislodged & Transferred to Spent Pool for insp.W/980127 Ltr ML17229A5501997-12-0505 December 1997 LER 97-008-00:on 971107,inadequate CR Ventilation Surveillance Resulted in Condition Prohibited by Ts.Caused by non-cognitive Personnel Error.Operating Procedure 2-1900050 Was revised.W/971205 Ltr ML17309A9091997-12-0202 December 1997 LER 97-011-00:on 971102,non-conservative RAS Set Point Resulted in Operation Prohibited by Ts.Caused by Inadequate Set Point & Instrument Loop Scaling Process.Revised ESFAS Functional Tp W/Proper Set point.W/971202 Ltr ML17229A5391997-11-26026 November 1997 LER 97-010-00:on 971027,inadvertant Core Alteration Prohibited by TS Occurred.Caused by CEA Failure to Detach from Ugs.Safety Evaluation Was Performed & Procedural Rev Made to Continue Upper Guide Structure move.W/971126 Ltr ML17229A5151997-11-0707 November 1997 LER 97-007-00:on 971008,inoperable Containment Cooling Fan Resulted in Operation of Facility Outside Design Basis. Caused by non-cognitive Personnel Error.Ccs Operation Was Revised & Issued on 971013.W/971107 Ltr ML17229A4991997-10-17017 October 1997 LER 97-009-00:on 970917,inoperable PORV Block Valve Resulted in Operation Prohibited by Tech Specs Occurred.Caused by Plant GL 89-10 Program Plan to Review Plant Manager Action Item Sys.Porv Block Valve V-1403 restored.W/971017 Ltr ML17309A9011997-08-27027 August 1997 LER 97-008-00:on 970728,mechanical Fire Penetrations Were Inoperable & Outside App R Design Bases.Caused by Seal Mfg Not Providing Formal Documentation for Installed Seals. Modified Inoperable Fire penetrations.W/970827 Ltr ML17229A4311997-07-29029 July 1997 LER 97-006-00:on 970630,discovered Inadequate Testing of Engineered Safety Features Subgroup Relays.Caused by Inadequacy in Implementing TS Requirements in Surveillance Procedures.Revised Surveillance procedures.W/970729 Ltr ML17229A4241997-07-25025 July 1997 LER 97-005-00:on 970625,discovered That Hot Shutdown Control Panel Shutdown Cooling Flow indicator,FI-3306 Inoperable. Caused by Weakness in Work Order & Procedure Used to Repair FI-3306.Section Meeting W/I&C Planners held.W/970725 Ltr ML17229A3971997-07-11011 July 1997 LER 97-004-00:on 970611,discovered Incorrect Original Cable Tray Fire Stop Assembly Installation Was Outside App R Design Basis.Caused by Personnel Error.Hourly Fire Watch Patrols Will Be posted.W/970711 Ltr ML17229A3871997-06-19019 June 1997 LER 97-003-00:on 970521,determined Required Post Maint Open Stroke Test for Valve V3245,2B2 SIT Discharge Check Valve, Had Not Been Performed.Caused by Personnel Error.Procedure revised.W/970619 Ltr ML17229A3841997-06-17017 June 1997 LER 97-002-00:on 970518,containment Sump Debris Screen Was Not IAW Design Due to Gaps in Screen Encl.Performed SER to Document Containment Sump Design requirements.W/970617 Ltr ML17229A3751997-06-0202 June 1997 LER 97-006-00:on 970501,operation Was Prohibited by TS Due to Inadequately Tested Degraded Voltage Sys.Revised Unit 1 ESFAS Surveillance Test procedure.W/970602 Ltr ML17229A3611997-05-29029 May 1997 LER 97-007-00:on 970502,reactor Coolant Pump Oil Collection Sys Was Outside App R Design Bases.Identified Leak Sites Were Repaired & Mods to RCP Oil Collection Sys to Capture Any Future Leakage from areas.W/970529 Ltr ML17229A3491997-05-21021 May 1997 LER 97-001-00:on 970423,containment Isolation Actuation Occurred.Caused by Increased Radiation Levels During Removal of Upper Guide Structure.Proper Actuation of Containment Isolation Components Was verified.W/970521 Ltr ML17229A3441997-05-13013 May 1997 LER 97-005-00:on 970419,reactor Was Shutdown Due to Reactor Coolant Pressure Boundary Leakage.Hot Cracking Was Caused by Weld Contamination.Repairs to RCPB Were Completed & 1A SDC Train Was Restored to Svc ML17229A3141997-04-30030 April 1997 LER 97-004-00:on 970402,refueling Machine Was Operating in Manner Prohibited by TS Due to Original Design of Refueling Machine Bypass Feature Conflicting W/Ts Requirements. Eliminated Overload Cut Off Limit bypass.W/970430 Ltr ML17229A2951997-03-31031 March 1997 LER 97-003-00:on 970304,automatic Rt Resulted from Loss of Electrical Power to 1A2 Rc Pump.Rcp Breaker Was Replaced & Pump Was Returned to svc.W/970331 Ltr ML17229A2721997-03-21021 March 1997 LER 97-002-00:on 970221,operation in Excess of Max Rated Thermal Power Occurred Due to Digital Data Processing Sys (Ddps) Calorimetric Error.Verified Acceptable Performance of Ddps Functions & Reviewed Software mods.W/970321 Ltr 1999-07-06
[Table view] Category:RO)
MONTHYEARML17241A4891999-10-0707 October 1999 LER 99-004-00:on 990912,noted That MSSV Surveillance Was Outside of TS Requirements.Caused by Setpoint Drift.Subject MSSVs Are Being Refurbished & Retested Prior to Unit Startup from SL1-16 Refueling Outage.With 991007 Ltr ML17241A4111999-07-16016 July 1999 LER 99-007-00:on 990610,unplanned Cooldown Transient Occurred Due to Personnel Error.Trained & Briefed Personnel & Revised Procedures.With 990716 Ltr ML17241A4031999-07-0606 July 1999 LER 99-006-00:on 990605,sub-critical Reactor Trip Occurred Due to Inadvertent MSIV Opening.Caused by Personnel Error. Provided Operation Supervision Instruction to Operating Crews,Stand Down Meetings & Operator Aids.With 990706 Ltr ML17241A4041999-07-0606 July 1999 LER 99-005-00:on 990604,CEA Drop Resulted in Manual Reactor Trip.Caused by Procedural Inadequacies.Procedure Changes Are Planned to Correct Lack of Procedural Guidance for CEA Subgroup Power Switch Replacement.With 990706 Ltr ML17241A3941999-06-30030 June 1999 LER 99-004-01:on 990415,as Found Cycle 10 Psv Setpoints Were Outside TS Limits.Caused by Manufacturing Process Defect. All Three Psvs Were Replaced with pre-tested Valves During Cycle 11 Refueling Outage.With 990630 Ltr ML17241A3551999-06-0404 June 1999 LER 99-002-00:on 990505,both Trains of Safety Injection Actuation Were Blocked During Surveillance.Caused by Procedure Error.Procedure Revised.With 990604 Ltr ML17241A3321999-05-17017 May 1999 LER 99-004-00:on 990415,determined That as Found Cycle 10 Psv Setpoints Outside TS Limits.Root Cause Under Investigation.Psvs Replaced with pe-tested Valves During Cycle 11 ML17241A3271999-05-0606 May 1999 LER 99-003-00:on 990406,ECCS Suction Header Leak Resulted in Both ECCS Trains Being Inoperable & Entry Into TS 3.0.3. Caused by Chloride Induced OD Stress Corrosion Cracking of Piping.Made Code Repairs & Coated Piping.With 990506 Ltr ML17229B0791999-04-0707 April 1999 LER 99-001-00:on 990309,discovered Inadequate Design & IST SRs for Iodine Removal Sys (Irs).Caused by Original Design Inadequacies & Personnel Error.Naoh Tank Vent Valve V07233 Was Tagged Open.With 990407 Ltr ML17229B0801999-04-0707 April 1999 LER 99-002-00:on 990311,SG ECT Error Caused Operation with Condition Prohibited by Ts.Caused by Deficiencies in Data Analysis Guideline Instructions.Licensee Will Change Data Analysis Guidelines for Lead Analysts.With 990407 Ltr ML17229B0541999-03-10010 March 1999 LER 99-001-00:on 990211,inadequate TS SRs for SIT & SDC Isolation Valves Were Noted.Caused by Failure to Correctly Implement TS Srs.Submitted LAR to Align Required TS SR with Design Bases Requirements Being Verified.With 990310 Ltr ML17229A9901999-01-20020 January 1999 LER 98-009-00:on 981223,noted That Facility Operated Outside of Design Basis.Caused by non-conservative MSLB Analysis Inputs.Will Review SR Component Differences Between Units & Will re-baseline LTOP Analysis.With 990120 Ltr ML17229A9821999-01-0404 January 1999 LER 98-010-00:on 981207,RCS Boron Sample Frequency Required by Ts,Was Exceeded by Twelve Minutes.Caused by Personnel Error.Equipment Clearance Order Was Lifted to Draw Required Sample & Operations Procedure Was Changed.With 990104 Ltr ML17229A9611998-12-22022 December 1998 LER 97-002-01:on 981204,containment Sump Debris Screen Was Not IAW Design.Caused by Inadequate C/As for Sump Screen Anamolies.All Identified Sump Screen Deficiencies Were Dispositioned &/Or Repaired.With 981222 Ltr ML17229A9561998-12-15015 December 1998 LER 98-008-00:on 981118,missed TS SG U Tube Insp.Caused by Encoding Errors While Using Remote Positioning Fixtures.All SG Tube Surveyed.With 981215 Ltr ML17229A9301998-11-25025 November 1998 LER 98-005-01:on 980807,discovered That New MOV Methodology Caused Past PORV Block Valve Operability Problem.Caused by Inadequacies in Original Vendor MOV Methodology.Planned Valve Mods Will Be Implemented During Cycle 11 1998 Outage ML17229A9021998-11-0404 November 1998 LER 98-008-00:on 981008,inadequate Reactor Protection Sys Trip Bypass TS Was Noted.Caused by Poorly Worded Ts. Submitted LAR to Clarify Power Requirements for High Rate of Power Trips.With 981104 Ltr ML17229A8771998-10-14014 October 1998 LER 98-006-00:on 980918,inadvertent Afas Actuation Was Noted.Caused by Degradation of Multiple Afas Power Supplies. Replaced Afas Power Supplies & Revised Procedures.With 981014 Ltr ML17229A8761998-10-14014 October 1998 LER 98-007-00:on 980918,identified Discrepancies Between Fire Protection Design Requirements & Field Conditions. Caused by Inadequate Translation & Implementation of Fire Protection Requirements.Procedures Revised.With 981014 Ltr ML17229A8511998-09-0202 September 1998 LER 98-005-00:on 980807,discovered That PORV Margins Were Insufficient to Accommodate Addl Conservatism.Caused by Inadequacies in Original Vendor MOV Methodology.Will Implement Planned Valve Actuator mods.W/980902 Ltr ML17229A8201998-07-29029 July 1998 LER 98-007-00:on 980630,inadequate Procedure May Have Resulted in SBO Recovery Complications.Caused by Inadequate Procedures.Attached Caution Tags to Appropriate Control switches.W/980729 Ltr ML17229A7411998-05-28028 May 1998 LER 98-004-00:on 980430,discovered Waste Gas Decay Tank Operation W/O Available Oxygen Analyzers,Which Is Prohibited by Ts.Caused by Inadequate Licensee Review of License Amend. Oxygen Analyzer recalibrated.W/980528 Ltr ML17229A7381998-05-21021 May 1998 LER 98-006-00:on 980421,missed EDG Fuel Oil Sample Surveillance Was Noted.Caused by Personnel Error.Revised Fuel Oil Sampling Service Purchase Order & Revised Site procedure.W/980521 Ltr ML17229A7011998-04-27027 April 1998 LER 98-003-00:on 980326,discovered Containment Pressure Instrumentation Design Single Failure Vulnerability.Caused by Inadequate Design by Personnel Error.Removed RPS & ESFAS Containment Pressure Bypass Keys immediately.W/980427 Ltr ML17229A6761998-04-0202 April 1998 LER 98-005-00:on 980305,identified Two Conditions That Were Outside App R Design Bases.Caused by Design Oversight During Development of Original App R Safe SD Design.Established 30 Minute Roving Fire Watches & Provided training.W/980402 Ltr ML17229A6731998-03-26026 March 1998 LER 98-002-00:on 980224,radiation Monitor Surveillance Inadequacies Led to Operating of Facility Prohibited by Tss. Caused by Congnitive Personnel Error.Permanent Procedure Changes Were implemented.W/980326 Ltr ML17229A6551998-03-0505 March 1998 LER 98-001-00:on 980206,high/low Pressure Shutdown Cooling Interface Was Noted Outside App R Design Bases.Caused by Personnel Error.Addl Guidance Was Provided to Engineering Dept personnel.W/980305 Ltr ML17229A6281998-02-19019 February 1998 LER 98-004-00:on 980121,emergency Lighting Outside App R Design Bases Occurred.Caused by Congnitive Personnel Error During Translation of App R Section Iii.Procedures Onop 1 & 2 ONP-100.01 Were Issued for Use on 980206.W/980219 Ltr ML17229A6211998-02-0909 February 1998 LER 98-003-00:on 980110,manual Rt Due to DEH Leak at Turbine Test Block Was Noted.Caused by o-ring Extrusion.Shortened Bolts by About 0.125 & Reinstalled at Correct Torque values.W/980209 Ltr ML17229A6191998-02-0404 February 1998 LER 98-002-00:on 980105,CIS Bistable in Bypass Resulted in Condition Prohibited by Tss.Caused by Personnel Error. Radiation Monitor Was Restored to service.W/980204 Ltr ML17229A6161998-02-0303 February 1998 LER 98-001-00:on 980104,inadvertent RPS Actuation Occurred Due to Personnel Error.Caused by Procedural Inadequacies & Inadequate self-checking by Licensed Utility Personnel. Placards Have Been Placed in CRs.W/980203 Ltr ML17229A6051998-01-27027 January 1998 LER 97-010-01:on 971027,inadvertent Core Alteration Prohibited by TSs Were Noted Due to Stuck Cea.Caused by Personnel Error.Cea #24 Was Dislodged & Transferred to Spent Pool for insp.W/980127 Ltr ML17229A5501997-12-0505 December 1997 LER 97-008-00:on 971107,inadequate CR Ventilation Surveillance Resulted in Condition Prohibited by Ts.Caused by non-cognitive Personnel Error.Operating Procedure 2-1900050 Was revised.W/971205 Ltr ML17309A9091997-12-0202 December 1997 LER 97-011-00:on 971102,non-conservative RAS Set Point Resulted in Operation Prohibited by Ts.Caused by Inadequate Set Point & Instrument Loop Scaling Process.Revised ESFAS Functional Tp W/Proper Set point.W/971202 Ltr ML17229A5391997-11-26026 November 1997 LER 97-010-00:on 971027,inadvertant Core Alteration Prohibited by TS Occurred.Caused by CEA Failure to Detach from Ugs.Safety Evaluation Was Performed & Procedural Rev Made to Continue Upper Guide Structure move.W/971126 Ltr ML17229A5151997-11-0707 November 1997 LER 97-007-00:on 971008,inoperable Containment Cooling Fan Resulted in Operation of Facility Outside Design Basis. Caused by non-cognitive Personnel Error.Ccs Operation Was Revised & Issued on 971013.W/971107 Ltr ML17229A4991997-10-17017 October 1997 LER 97-009-00:on 970917,inoperable PORV Block Valve Resulted in Operation Prohibited by Tech Specs Occurred.Caused by Plant GL 89-10 Program Plan to Review Plant Manager Action Item Sys.Porv Block Valve V-1403 restored.W/971017 Ltr ML17309A9011997-08-27027 August 1997 LER 97-008-00:on 970728,mechanical Fire Penetrations Were Inoperable & Outside App R Design Bases.Caused by Seal Mfg Not Providing Formal Documentation for Installed Seals. Modified Inoperable Fire penetrations.W/970827 Ltr ML17229A4311997-07-29029 July 1997 LER 97-006-00:on 970630,discovered Inadequate Testing of Engineered Safety Features Subgroup Relays.Caused by Inadequacy in Implementing TS Requirements in Surveillance Procedures.Revised Surveillance procedures.W/970729 Ltr ML17229A4241997-07-25025 July 1997 LER 97-005-00:on 970625,discovered That Hot Shutdown Control Panel Shutdown Cooling Flow indicator,FI-3306 Inoperable. Caused by Weakness in Work Order & Procedure Used to Repair FI-3306.Section Meeting W/I&C Planners held.W/970725 Ltr ML17229A3971997-07-11011 July 1997 LER 97-004-00:on 970611,discovered Incorrect Original Cable Tray Fire Stop Assembly Installation Was Outside App R Design Basis.Caused by Personnel Error.Hourly Fire Watch Patrols Will Be posted.W/970711 Ltr ML17229A3871997-06-19019 June 1997 LER 97-003-00:on 970521,determined Required Post Maint Open Stroke Test for Valve V3245,2B2 SIT Discharge Check Valve, Had Not Been Performed.Caused by Personnel Error.Procedure revised.W/970619 Ltr ML17229A3841997-06-17017 June 1997 LER 97-002-00:on 970518,containment Sump Debris Screen Was Not IAW Design Due to Gaps in Screen Encl.Performed SER to Document Containment Sump Design requirements.W/970617 Ltr ML17229A3751997-06-0202 June 1997 LER 97-006-00:on 970501,operation Was Prohibited by TS Due to Inadequately Tested Degraded Voltage Sys.Revised Unit 1 ESFAS Surveillance Test procedure.W/970602 Ltr ML17229A3611997-05-29029 May 1997 LER 97-007-00:on 970502,reactor Coolant Pump Oil Collection Sys Was Outside App R Design Bases.Identified Leak Sites Were Repaired & Mods to RCP Oil Collection Sys to Capture Any Future Leakage from areas.W/970529 Ltr ML17229A3491997-05-21021 May 1997 LER 97-001-00:on 970423,containment Isolation Actuation Occurred.Caused by Increased Radiation Levels During Removal of Upper Guide Structure.Proper Actuation of Containment Isolation Components Was verified.W/970521 Ltr ML17229A3441997-05-13013 May 1997 LER 97-005-00:on 970419,reactor Was Shutdown Due to Reactor Coolant Pressure Boundary Leakage.Hot Cracking Was Caused by Weld Contamination.Repairs to RCPB Were Completed & 1A SDC Train Was Restored to Svc ML17229A3141997-04-30030 April 1997 LER 97-004-00:on 970402,refueling Machine Was Operating in Manner Prohibited by TS Due to Original Design of Refueling Machine Bypass Feature Conflicting W/Ts Requirements. Eliminated Overload Cut Off Limit bypass.W/970430 Ltr ML17229A2951997-03-31031 March 1997 LER 97-003-00:on 970304,automatic Rt Resulted from Loss of Electrical Power to 1A2 Rc Pump.Rcp Breaker Was Replaced & Pump Was Returned to svc.W/970331 Ltr ML17229A2721997-03-21021 March 1997 LER 97-002-00:on 970221,operation in Excess of Max Rated Thermal Power Occurred Due to Digital Data Processing Sys (Ddps) Calorimetric Error.Verified Acceptable Performance of Ddps Functions & Reviewed Software mods.W/970321 Ltr 1999-07-06
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML17241A4891999-10-0707 October 1999 LER 99-004-00:on 990912,noted That MSSV Surveillance Was Outside of TS Requirements.Caused by Setpoint Drift.Subject MSSVs Are Being Refurbished & Retested Prior to Unit Startup from SL1-16 Refueling Outage.With 991007 Ltr ML17241A4951999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for St Lucie,Units 1 & 2.With 991014 Ltr ML17241A4741999-08-31031 August 1999 Rev 1 to PCM 99016, St Lucie Unit 1,Cycle 16 Colr. ML17241A4591999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for St Lucie,Units 1 & 2.With 990913 Ltr ML17241A4301999-07-31031 July 1999 Monthly Operating Repts for Jul 1999 for St Lucie Units 1 & 2.With 990805 Ltr ML17241A4111999-07-16016 July 1999 LER 99-007-00:on 990610,unplanned Cooldown Transient Occurred Due to Personnel Error.Trained & Briefed Personnel & Revised Procedures.With 990716 Ltr ML17241A4031999-07-0606 July 1999 LER 99-006-00:on 990605,sub-critical Reactor Trip Occurred Due to Inadvertent MSIV Opening.Caused by Personnel Error. Provided Operation Supervision Instruction to Operating Crews,Stand Down Meetings & Operator Aids.With 990706 Ltr ML17241A4041999-07-0606 July 1999 LER 99-005-00:on 990604,CEA Drop Resulted in Manual Reactor Trip.Caused by Procedural Inadequacies.Procedure Changes Are Planned to Correct Lack of Procedural Guidance for CEA Subgroup Power Switch Replacement.With 990706 Ltr ML17241A4091999-06-30030 June 1999 Monthly Operating Repts for June 1999 for St Lucie,Units 1 & 2.With 990712 Ltr ML17241A3941999-06-30030 June 1999 LER 99-004-01:on 990415,as Found Cycle 10 Psv Setpoints Were Outside TS Limits.Caused by Manufacturing Process Defect. All Three Psvs Were Replaced with pre-tested Valves During Cycle 11 Refueling Outage.With 990630 Ltr ML17355A3681999-06-30030 June 1999 Revised Update to Topical QA Rept, Dtd June 1999 ML17241A3551999-06-0404 June 1999 LER 99-002-00:on 990505,both Trains of Safety Injection Actuation Were Blocked During Surveillance.Caused by Procedure Error.Procedure Revised.With 990604 Ltr ML17241A3631999-05-31031 May 1999 Monthly Operating Repts for May 1999 for St Lucie Units 1 & 2.With 990610 Ltr ML17241A3321999-05-17017 May 1999 LER 99-004-00:on 990415,determined That as Found Cycle 10 Psv Setpoints Outside TS Limits.Root Cause Under Investigation.Psvs Replaced with pe-tested Valves During Cycle 11 ML17241A3271999-05-0606 May 1999 LER 99-003-00:on 990406,ECCS Suction Header Leak Resulted in Both ECCS Trains Being Inoperable & Entry Into TS 3.0.3. Caused by Chloride Induced OD Stress Corrosion Cracking of Piping.Made Code Repairs & Coated Piping.With 990506 Ltr ML17241A3331999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for St Lucie,Units 1 & 2.With 990517 Ltr ML17229B0801999-04-0707 April 1999 LER 99-002-00:on 990311,SG ECT Error Caused Operation with Condition Prohibited by Ts.Caused by Deficiencies in Data Analysis Guideline Instructions.Licensee Will Change Data Analysis Guidelines for Lead Analysts.With 990407 Ltr ML17229B0841999-04-0707 April 1999 Rev 2 to PSL-ENG-SEMS-98-102, Engineering Evaluation of ECCS Suction Lines. ML17229B0791999-04-0707 April 1999 LER 99-001-00:on 990309,discovered Inadequate Design & IST SRs for Iodine Removal Sys (Irs).Caused by Original Design Inadequacies & Personnel Error.Naoh Tank Vent Valve V07233 Was Tagged Open.With 990407 Ltr ML17229B0961999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for St Lucie,Units 1 & 2.With 990408 Ltr ML17229B0541999-03-10010 March 1999 LER 99-001-00:on 990211,inadequate TS SRs for SIT & SDC Isolation Valves Were Noted.Caused by Failure to Correctly Implement TS Srs.Submitted LAR to Align Required TS SR with Design Bases Requirements Being Verified.With 990310 Ltr ML17229B0461999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for St Lucie,Units 1 & 2.With 990310 Ltr ML17229B0051999-01-31031 January 1999 Monthly Operating Repts for Jan 1999 for St Lucie,Units 1 & 2.With 990211 Ltr ML17229A9901999-01-20020 January 1999 LER 98-009-00:on 981223,noted That Facility Operated Outside of Design Basis.Caused by non-conservative MSLB Analysis Inputs.Will Review SR Component Differences Between Units & Will re-baseline LTOP Analysis.With 990120 Ltr ML17229A9961999-01-14014 January 1999 SG Tube Inservice Insp Special Rept. ML17229A9821999-01-0404 January 1999 LER 98-010-00:on 981207,RCS Boron Sample Frequency Required by Ts,Was Exceeded by Twelve Minutes.Caused by Personnel Error.Equipment Clearance Order Was Lifted to Draw Required Sample & Operations Procedure Was Changed.With 990104 Ltr ML17229A9831998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for St Lucie,Units 1 & 2.With 990111 Ltr ML17229A9611998-12-22022 December 1998 LER 97-002-01:on 981204,containment Sump Debris Screen Was Not IAW Design.Caused by Inadequate C/As for Sump Screen Anamolies.All Identified Sump Screen Deficiencies Were Dispositioned &/Or Repaired.With 981222 Ltr ML17229A9561998-12-15015 December 1998 LER 98-008-00:on 981118,missed TS SG U Tube Insp.Caused by Encoding Errors While Using Remote Positioning Fixtures.All SG Tube Surveyed.With 981215 Ltr ML17241A3581998-12-0909 December 1998 Changes,Tests & Experiments Made as Allowed by 10CFR50.59 for Period of 970526-981209. ML17229A9421998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for St Lucie,Units 1 & 2.With 981215 Ltr ML17229A9301998-11-25025 November 1998 LER 98-005-01:on 980807,discovered That New MOV Methodology Caused Past PORV Block Valve Operability Problem.Caused by Inadequacies in Original Vendor MOV Methodology.Planned Valve Mods Will Be Implemented During Cycle 11 1998 Outage ML17229A9021998-11-0404 November 1998 LER 98-008-00:on 981008,inadequate Reactor Protection Sys Trip Bypass TS Was Noted.Caused by Poorly Worded Ts. Submitted LAR to Clarify Power Requirements for High Rate of Power Trips.With 981104 Ltr ML17241A4931998-11-0101 November 1998 Statement of Account for Period of 981101-990930 for Suntrust Bank,As Trustee for Florida Municipal Power Agency Nuclear Decommissioning Trust (St Lucie Project). ML17229A9051998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for St Lucie,Units 1 & 2.With 981110 Ltr ML17229A8871998-10-19019 October 1998 Part 21 Rept Re Potential Defect in Swagelok Stainless Steel Front Ferrule,Part Number SS-503-1 Which Was Machined with Improper Length.C/A Includes Insp Equipment That Will 100% Identify Short Length ML17229A8781998-10-19019 October 1998 Part 21 Rept Re Potential Defect in Swagelok Stainless Steel Front Ferrule,Part Number SS-503-1,which Was Machined with Improper Length.Insp Equipment That Will 100% Identify Short Length ML17229A8771998-10-14014 October 1998 LER 98-006-00:on 980918,inadvertent Afas Actuation Was Noted.Caused by Degradation of Multiple Afas Power Supplies. Replaced Afas Power Supplies & Revised Procedures.With 981014 Ltr ML17229A8761998-10-14014 October 1998 LER 98-007-00:on 980918,identified Discrepancies Between Fire Protection Design Requirements & Field Conditions. Caused by Inadequate Translation & Implementation of Fire Protection Requirements.Procedures Revised.With 981014 Ltr ML17229A8721998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for St Lucie Units 1 & 2.With 981009 Ltr ML17229A8511998-09-0202 September 1998 LER 98-005-00:on 980807,discovered That PORV Margins Were Insufficient to Accommodate Addl Conservatism.Caused by Inadequacies in Original Vendor MOV Methodology.Will Implement Planned Valve Actuator mods.W/980902 Ltr ML17229A8611998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for St Lucie,Units 1 & 2.With 980911 Ltr ML18066A2771998-08-13013 August 1998 Part 21 Rept Re Deficiency in CE Current Screening Methodology for Determining Limiting Fuel Assembly for Detailed PWR thermal-hydraulic Sa.Evaluations Were Performed for Affected Plants to Determine Effect of Deficiency ML17229A8481998-08-0707 August 1998 Rev 1 to PSL-ENG-SEFJ-98-013, St Lucie Unit 2,Cycle 10 Colr. ML17229A9461998-08-0707 August 1998 Rev 0 to PCM 98016, St Lucie Unit 2,Cycle 11 Colr. ML17229A8301998-07-31031 July 1998 Monthly Operating Repts for July 1998 for St Lucie,Units 1 & 2.W/980814 Ltr ML17229A8201998-07-29029 July 1998 LER 98-007-00:on 980630,inadequate Procedure May Have Resulted in SBO Recovery Complications.Caused by Inadequate Procedures.Attached Caution Tags to Appropriate Control switches.W/980729 Ltr ML17229A7981998-06-30030 June 1998 Monthly Operating Repts for June 1998 for St Lucie,Units 1 & 2.W/980713 Ltr ML17229A7701998-05-31031 May 1998 Monthly Operating Repts for May 1998 for St Lucie,Units 1 & 2.W/980612 Ltr ML17229A7411998-05-28028 May 1998 LER 98-004-00:on 980430,discovered Waste Gas Decay Tank Operation W/O Available Oxygen Analyzers,Which Is Prohibited by Ts.Caused by Inadequate Licensee Review of License Amend. Oxygen Analyzer recalibrated.W/980528 Ltr 1999-09-30
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ACCELERATED DISTRIBUTION DEMONS TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9005220165 DOC.DATE: 90/05/15 NOTARIZED: NO DOCKET FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 AUTH. NAME . AUTHOR AFFILIATION WEEKS,J.W. Florida Power & Light Co.
SAGER,D.A. Florida Power & Light Co.
RECIP.NAME RECIPIENT AFFILIATION
SUBJECT:
LER 90-005-00:on 900418,EDG automatic start due to loss of electrical bus caused by breaker failure.
t W/9 ltr.
DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR TITLE: 50.73/50.9 Licensee Event Report (LER),
ENCL A SIZE:
nciden~t Rpt, etc.
NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 NORRIS,J 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB11 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D NRR/DST/SICB 7E
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1 1 1 1 NBRQDST7~LBBD1 1 1 NRR/DST/SRXB 8E 1
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1 RGN2 FILE 01 1 1 EXTERNAL EG &G STUART ~ V A 4 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISHUBUTION LISTS FOR DOCUMENIS YOU DON'T NEED!
t FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF.. COPIES REQUIRED: LTTR 36 ENCL 36
P.O. Box14000, Juno Beach, FL 33408-0420 FPL MAV, 15 ~990 L-90-176 10 CFR 50.73 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:
Re: St. Lucie Unit 1 Docket No. 50-335 Reportable Event: 90-05 Date of Event: April 18, 1990 Emergency Diesel Generator Automatic Start due to Loss of Electrical Bus Caused b Breaker Failure The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.
Very truly yours, D. A. S er Site St.
V c Lu 'lant President DAS/GRM/slh Attachment cc: Stewart D. Ebneter, Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant 9005220165 900515 PDR ADOCK 05000335 PDC an FPL Gcoup company
fPl /@caela ot US. RUCLEAR REG'AATORY COMMISSION IRC C~ %i APPROVED OMS NO. 31504104 3 45)
LICENSEE EVENT REPORT (LER) EXPIRES 8/31/85 FACILITYNAME (1) DOCKET NUMBER (2 PAGE 3 St. Lucie Unit 1 0 500033 510 0 3 TITLE (4)
Emergency Diesel Generator Automatic Start Due to Loss of Electrical Bus Caused by Breaker Failure EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(6)
MONTH DAY YEAR YEAR. MONTH DAY YEAR FACILITYNAMES DOCKET NUMBER(S)
NU N M NIA 0 5000 041890 9 0 0 0 5 0 0 0 5 1 5 9 0 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR OPERATING 5 Check one or more of the followin 11 MODE (9) 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)
POWER 20.405(a)(1) (I) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c)
LEVEL
(<<) 0 0 0 20.405(a) (1 )(Ii) 50.36(c)(2) 50.73(a)(2)(vll) OTHER (Specify ln Abstract 20.405(a) (1 )(lli) 50.73(a)(2) (I) 50.73(a)(2)(viil)(A) below and in Text 20.405(a)(1)(iv) 50.73(a)(2) (ii) 50.73(a)(2)(vill)(B) NRC Form 366A) 20.405(a)(1)(v) 50.73(a)(2)(ill) 50.73(a)(2)(x)
LICENSEE CONTACT FOR THIS LER (12)
NAME AREA CODE J. W. Weeks, Shift Technical Advisor 4 0 7 465- 3 550 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13 CAUSE SYSTEM COMPONENT MANUFAC- TURER REPORTABLE TO NPRDS GAUSF SYSTFM COMPONFNT MANUFAC- TURER R(PORTABLE 0 NPRDS B E L B K R 1 2 0 I I SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED SUBMISSION YES (Ifyes, complete EXPECTED SUBMISSION DATE) NO DATE (15)
ABSTRACT (Limit to 1400 spaces. I.e. approximately fifteen single-space typewritten lines)(16)
At 1105 on April 18, 1990, while St. Lucie Unit1 was in Mode 5, the Auxiliary Transformer breaker to the 1B2 4160V bus (breaker no. 20301) was being racked in to prepare for the planned startup of the unit. When the breaker control fuses were installed, the breaker closed in. This caused the 1B Startup Transformer to be shorted to the Main Generator and the Main Transformers, which were deenergized. As a'result, the 1B Startup Transformer feeder breaker to the 2B4 4160V bus (breaker no. 2-20705) then tripped on overcurrent. Power was lost to the 'B'ide electrical buses.
The 1B Emergency Diesel Generator then started and'picked up the 1B3 emergency bus loads as designed.
The root cause of the event was equipment failure. Excessive wear on the breaker closing mechanism mounting plates allowed the closing latch mechanism to move excessively which prevented the closing latch from performing its designed function. The charging spring motor charged the closing spring but the closing latch would not latch the mechanism. This allowed the breaker to close in as soon as the closing spring was charged.
Corrective actions taken were to test the 1B Startup Transformer, the Auxiliary Transformers, the Main Transformers, and the Main Generator to ensure no damage had occurred to them, and to remove the Auxiliary Transformer breaker and ship it to the repair vendor for troubleshooting and repair. Other similar breakers were inspected. Four were shipped to the vendor for repair.
fPL Saca+4o tl Ua. NNXEAR REGUlATORY COMMISSION AC Fore X4 APP ROVEO 0MB NO. 315001/M (N+
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION EXPIRES 8/31/85 FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)
YEAR EQUENTIAL REVISION NUMBER : NUMBER St. Lucie Unit 1 0 500 033 59 0 0 0 5 0 0 0 2 0 3 TEXT (Ifmore space is required, use additional NRC Form 366A's) (1 7)
At 1105 on April 18, 1990, St. Lucie Unit 1 was in Mode 5 after completing a refueling outage. Plant personnel were racking the 41 60V circuit breaker number 20301 into its cubicle in preparation for plant startup. This breaker is the Auxiliary Transformer (EIIS:EL) supply breaker to the 1B24160V switchgear. This breaker is closed in by the plant operators when the unit is on line and on-site power is being transferred from the off-site supplied Startup Transformers (EIIS:EA) to the Auxiliary Transformers powered from the unit Main Generator (EIIS:EL).
At the time the breaker was being racked in, the Main Generator was deenergized and was not spinning. The Main Transformers (EIIS:EL) and Auxiliary Transformers were also deenergized. After the breaker was installed in its cubicle, the control fuses for operating the breaker were installed. At this time the spring charging motor charged the closing spring, but the latching mechanism failed to latch open the closing spring and the breaker closed. No'operating switches were manipulated. When the breaker closed, the Auxiliary Transformer became energized from the Startup Transformer, as did the Main Generator and Main Transformers. This caused a large in-rush of current which caused the 1B Startup Transformer feeder breaker number 2-20705 to trip on overcurrent. Subsequently all 41 60V power to the 'B'ide electrical buses was lost. The 1B Emergency Diesel Generator (EIIS:EK) started on detection of an undervoltage condition on the 1B3 emergency bus (EIIS:EB) and the Diesel Generator picked up the emergency bus loads as designed. The faulty Auxiliary Transformer breaker, which was now deenergized, was then racked back out of its cubicle.
Troubleshooting commenced to determine whether damage had occurred to the Startup Transformer or its feeder breaker. At 1345 on April 18, 1990, it was determined that the Startup Transformer breaker had operated correctly and was not damaged. At this time the breaker was closed in which restored normal power to the non-emergency buses. The 1B Diesel Generator was paralleled to the grid and was then secured. Off-site power was then carrying all buses in the normal configuration.
The faulty breaker was bench tested and the charging motor operated but the breaker failed to latch open when control power was provided to the breaker. This had not occurred when it was bench tested prior to installation in its cubicle. The breaker was then shipped to the repair vendor for further troubleshooting and repair.
The root cause of the event is due to equipment failure. The front plates and splined bearings on the breaker frame are the same size for larger breakers (Westinghouse model nos. 50DHP350 and 75DHP500) as for smaller breakers (Westinghouse model no. 50DHP250). The larger breakers have larger charging motors and charging springs which induce more force on the mounting frames.
Therefore, after repeated spring chargings, the holes in the breaker frame where the plates and bearings are press-fit mounted became enlarged, allowing some movement to take place. This movement was enough to cause the closing latch to fail to engage when the closing spring was charged, thus allowing the breaker to close inadvertently.
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~ c FFL Fcccccfc US. NUCUAR REGULATORYCOMMISION
~f fflCfees APPROVED OM B NO. 31500104
~ )Cl)CCC) LICENSEE EVENT REPORT (LER) TEXT CONTINUATION EXPIRES 8/3) )85 FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)
YEAR QI@NTIAL RF Vl)IP St. Lucie Unit 1 05000335 9 0 0 0 5 0 0 0 3 0 3 TEXT (lfmore space is requIred, use additional NRC Form 366A's) (1 7)
The Auxiliary Transformer breaker was racked into its cubicle in preparation for the unit startup. It had been previously bench tested and was in working order. However, when its control fuses were installed, it malfunctioned and closed in. This caused the Main Generator, Main Transformers, and Auxiliary Transformers to become energized from the 1B Startup Transformer. An overcurrent condition resulted causing the Startup Transformer breaker to trip. This then caused loss of power to the 'B'ide electrical buses. The 1B Emergency Diesel Generator started on undervoltage on the 1B3 emergency bus. The Diesel Generator picked up the 1B3 bus as designed and power was maintained on the emergency bus.
The Auxiliary Transformers and their respective switchgear are not safety related components.
However, the failure of this breaker caused the loss of electrical power to the 'B'ide, including the safety related emergency bus; thus forcing the 1B Emergency Diesel Generator to start, reenergize the 1B3 bus, and perform its designed safety function. Therefore this event is reportable to the NRC under 10CFR50.73(a)(2)(iv) as any event or condition that resulted in manual or automatic actuation of any Engineered Safety Feature.
Due to the fact that the 1B Emergency Diesel Generator started and loaded the 1B3 emergency bus as designed, and that the 'A'ide electrical buses were not affected; the health and safety of the public was not endangered at any time during this event.
The 1B Startup Transformer, its feeder breaker, Auxiliary Transformers, Main Transformers, and Main Generator were tested to ensure no damage had occurred.
r The faulty breaker was removed and sent to the repair vendor for troubleshooting and repair. The vendor recommended spot welding the bearings in place on the breaker frames to prevent future movement. This was reviewed by FPL Engineering and was approved. The breaker was repaired.
All other similar breakers on Unit 1 were inspected. Four were found to exhibit the same wear characteristics. These breakers were found to function properly;.however, they were sent to the repair vendor for rework to preclude future failures.
All similar breakers on Unit 2 will be inspected during the next refueling outage scheduled for September, 1990.
Westinghouse circuit breaker model nos. 50DHP350 and 75DHP500.
Failures of this type had been previously identified by the repair vendor during the overhaul of these breaker models at other facilities. No inspection criteria is provided in the Manufacturer's Technical Manual for checking for excessive axial or radial movement of the bearings.
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