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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML17335A7641998-10-22022 October 1998 LER 98-004-00:on 980923,inadvertent Actuation of Efs Occurred During Surveillance Testing.Caused by Personnel Error.Personnel Involved with Event Were Counseled & Procedure Changes Were Implemented.With 981022 Ltr ML20045B3021993-06-11011 June 1993 LER 93-001-00:on 930513,discovered That One Channel of Rvlms Inoperable Since Probe Replaced in Oct 1992.On 930507, Discovered That Two Sensors in Rvlms Indicating Wet.Caused by Design Error.Wiring Polarity corrected.W/930611 Ltr ML20024H2281991-05-21021 May 1991 LER 91-003-00:on 910421,actuation of EFW Sys During Plant Heatup Occurred Due to Low Once Through Steam Generator Level.Caused by Leaking Feedwater Recirculation Valve.Plant Startup Procedure OP 1102.02 Will Be revised.W/910521 Ltr ML20024H0861991-05-10010 May 1991 LER 91-002-00:on 910410,inadvertent Actuations of Combined Control Emergency Ventilation Sys Occurred.Caused by Transient Noise Spike.Mod Will Be Completed by 910531 to Install Time Delay in Actuation circuitry.W/910510 Ltr ML20024G9781991-05-10010 May 1991 LER 90-004-01:on 900531,discovered Degraded Fire Barrier Penetration During Insp Per Generic Ltr 86-10.Caused by Failure to Identify Adequate Fire Barrier Seal During 1983 Plant Walkdown.Fire Watch posted.W/910510 Ltr ML20029C3771991-03-22022 March 1991 LER 91-006-00:on 910222,core Protection Calculator Reactor Coolant Sys Flow Channels Not Being Calibrated within Tech Spec.Caused by Personnel Error.Operations Manager Counseled Operators Involved in event.W/910322 Ltr ML20029B1331991-02-27027 February 1991 LER 91-004-00:on 910125,control Room Radiation Monitor Alarm/Trip Setpoint Greater than Normal.Caused by Personnel Error.Operations Manager Will Counsel Shift Supervisors & Night Order Will Be posted.W/910227 Ltr ML20028H6841991-01-21021 January 1991 LER 90-021-00:on 901222,potential RCS Leak Noted in Area of Pressurizer Upper Level Instrument Nozzle.Caused by Pure Water Stress Corrosion Cracking.New Nozzle Installed Into Penetration from Shell OD.W/910121 Ltr ML20043C6801990-05-31031 May 1990 LER 89-025-01:on 891221,identified That Portion of Wall Located in Auxiliary Bldg Had Not Been Previously Identified as Tech Spec Fire Barrier.Caused by Personnel Error.Wall Being Upgraded to Tech Spec status.W/900531 Ltr ML20043C3781990-05-30030 May 1990 LER 90-012-00:on 900430,18 Month Channel Calibr of Liquid Radwaste Effluent Line Flow Monitor Not Performed as Required.Caused by Inadequate Controls to Ensure Followup Actions Taken in Timely Manner.Amends revised.W/900530 Ltr ML20043C0361990-05-23023 May 1990 LER 90-003-01:on 900423,discovered That Incorrect Monitoring Instrumentation for Radiological Effluent Ventilation Sys Utilized to Comply W/Tech Specs.Caused by Mgt Oversight.Logs Process Monitors Will Not Be used.W/900523 Ltr ML20043A7411990-05-17017 May 1990 LER 90-004-01:on 900212,discovered That Backwater Valve in Floor Drain Pipe in Emergency Feedwater Pump Room Missing. Caused by Inadequate Configuration Control.Backwater Pumps Installed & Will Be Included in Maint program.W/900517 Ltr ML20042F7681990-05-0101 May 1990 LER 90-002-01:on 900131,errors Identified in Calculation Used to Establish Calibr Tables for Steam Generator Water Level Transmitters.Errors in Original Calculation Not Identified.Calibr Procedures revised.W/900501 Ltr ML20042F7751990-05-0101 May 1990 LER 90-010-00:on 900401,personnel Failed to Complete Control Element Assembly Position Log.Caused by Surveillance Program Deficiencies & Lack of Mgt Involvement.Shift Briefing Completed & Procedure Change incorporated.W/900501 Ltr ML20042E1981990-04-10010 April 1990 LER 90-008-00:on 900311,determined That Seal Leakage Test for Containment Personnel Air Lock Had Not Been Performed, Per Tech Specs.Caused by Personnel Error.Procedure Revs Initiated & Personnel counseled.W/900410 Ltr ML20012F5051990-04-0505 April 1990 LER 89-027-00:on 891005,determined That Leakage Rate for Containment Isolation Check Valve in Excess of Leakage Rate Allowed Per Tech Specs.Caused by Loose Weld Slag in Valve Seat Area.Valve Cleaned & reassembled.W/900405 Ltr ML20012F5031990-04-0505 April 1990 LER 90-007-00:on 900306,RCS Charging Line Rendered Inoperable Due to Deficient Piping Support Weld.Caused by Inadequate Work Controls & post-installation Insp Processes. Field Walkdowns & Weld Insps initiated.W/900405 Ltr ML20012F5741990-04-0404 April 1990 LER 90-006-00:on 900305,instrumentation Channels Declared Inoperable,Resulting in Manual Actuation of Reactor Protection Sys.Caused by Procedural Deficiencies.Functional Tests of Log Power Level Channels performed.W/900404 Ltr ML20012C7221990-03-14014 March 1990 LER 90-004-00:on 900212,identified That No Backwater Valve Located in Floor Drain Pipe in One of Emergency Feedwater Pump Rooms.Caused by Inadequate Configuration Control. Valves Installed on 900215.W/900314 Ltr ML20012C1821990-03-12012 March 1990 LER 85-029-00:on 850520,unusual Motor Vibrations Identified on Svc Water Pump 2PM4A.On 861028,high Vibrations Noted on Upper Motor Bearings of Pump 2PM4B.Caused by Improper Installation.New Bearings installed.W/900312 Ltr ML20012B7271990-03-0808 March 1990 LER 89-049-01:on 891220,discovered That Okonite T-95 Tape Not Used to Tape Internal Motor Lead Connections for Main Feedwater Containment Isolation Valves.Caused by Personnel Error.Valves Taped According to Design drawing.W/900308 Ltr ML20012B5701990-03-0505 March 1990 LER 90-003-00:on 900201,failure to Perform Monthly Source Check Surveillance on Three Radiation Process Monitors Occurred.Caused by Inadequate Procedure Change by Personnel. Source Check on Monthly Basis implemented.W/900305 Ltr ML20011F6741990-03-0202 March 1990 LER 90-002-00:on 900131,errors Identified in Calculation Used to Establish Calibr Tables for Steam Generator Water Level Transmitters.Caused by Incorrect Static Pressure Assumption.Trip Setpoint Bistable increased.W/900302 Ltr ML20011F6781990-03-0101 March 1990 LER 89-026-00:on 891112,gaps in Piping Supports on Supply & Return Piping for Containment Coolers Identified.Caused by Inadequate Design Technique Used in Original Support Design. Shims Added Before Restart from outage.W/900301 Ltr ML20011F5831990-02-27027 February 1990 LER 89-022-01:on 891114,normal Offsite Power Feeder Breaker to 4,160-volt Ac ESF Bus Opened,Resulting in Loss of Power to Bus 2A3.Caused by Inadequate post-maint Test Controls. Test Switch Opened & Job Order changed.W/900227 Ltr ML20011F7311990-02-23023 February 1990 LER 90-001-00:on 900126,identified That Required Visual Insps of Containment Bldg After Entry Made Not Documented as Being Performed.Caused by Inadequate Procedural Guidance. Administrative Controls to Be established.W/900226 Ltr ML20006D7391990-02-0606 February 1990 LER 89-034-01:on 891031,determined That Tech Spec 3.9.1 Had Likely Been Violated Re Independent Circuits of Control Room Emergency Air Conditioning Sys.Caused by Inadequate Guidance Re Equipment Svc Removal.Procedures revised.W/900206 Ltr ML20011E2371990-01-31031 January 1990 LER 89-012-01:on 890626,RCS Backleakage Through Safety Injection Sys Check Valve Occurred Three Times.Caused by Missing Rollpins Which Connect Valve Disc to Valve Disc Shaft.Rollpins Replaced & Valves reassembled.W/900131 Ltr ML20011E2291990-01-31031 January 1990 LER 89-039-01:on 891116,discovered That Door for Upper North Electrical Penetration Room Open & Latch Mechanism Missing. Caused by Abnormally High Differential Pressure Across Door. Ventilation Sys Flow Balance performed.W/900131 Ltr ML20011E1451990-01-30030 January 1990 LER 89-024-00:on 891231,loose Terminal in Feedwater Control Sys Cabinet Resulted in Reactor Trip.Caused by Loose Connection on Terminal.Loose Connection Reterminated properly.W/900130 Ltr ML20006C1451990-01-29029 January 1990 LER 89-048-00:on 891228,automatic Reactor Trip & ESF Actuation Occurred as Result of Loss of All Main Feedwater Flow Due to Inadvertent Tripping of Main Feedwater Pump. Caused by Personnel error.O-rings replaced.W/900129 Ltr ML19354E3331990-01-22022 January 1990 LER 89-025-00:on 891221,two Piping Penetrations Located in Barrier Not Surveilled as Required by Tech Specs.Caused by Personnel Error.Fire Watch Posted When Necessary Per Tech Spec.W/900122 Ltr ML20006A8661990-01-22022 January 1990 LER 89-041-00:on 891221,automatic Actuation of Emergency Feedwater Sys Initiated.Caused by Lack of Adequate Procedural Guidance.Valve Positioners CV-2623 & CV-2673 Adjusted & Guidance Procedures developed.W/900122 Ltr ML20006A8671990-01-22022 January 1990 LER 89-042-01:on 891209,inadvertent Actuation of Control Room Emergency Ventilation Sys Occurred.Caused by Keying of Hand Held Radio in Vicinity of Chlorine Monitors by Technician.Technician counseled.W/900122 Ltr ML20005F1551990-01-18018 January 1990 LER 89-023-01:on 891117,noted That Channel a Not Responding to Change in Power Level & Declared Inoperable.Caused by Defective Preamplifier.Evaluation of Sys Design & Channel Functional Test initiated.W/900108 Ltr ML20006B6461990-01-18018 January 1990 LER 89-047-00:on 891219,RCS Temp Increased Above 250 F W/ Oxygen Concentration Greater than Tech Specs Limit.Caused by Inadequate Procedural Guidance.Plant Startup Procedure Revised to Require Chemistry Dept signoff.W/900118 Ltr ML19354D8291990-01-15015 January 1990 LER 89-044-00:on 891214,incorrect Assumptions & Calculational Errors Identified for Low Pressure Injection & Reactor Bldg Spray Pumps When Aligned to Take Suction from Reactor Bldg sump.W/900115 Ltr ML20005G1681990-01-0909 January 1990 LER 89-045-00:on 891210,discovered That U-bolt Supports on Two Containment Isolation Valves in Containment Bldg Not Installed & Pressurizer Sample Lines & Valves Considered Inoperable.Missing U-bolts installed.W/900109 Ltr ML20005F1481990-01-0808 January 1990 LER 89-042-00:on 891209,inadvertent Actuation of Control Room Emergency Ventilation Sys Occurred.Caused by Keying of Hand Held Radio in Vicinity of Chlorine Monitors by Technician.Technician counseled.W/900108 Ltr ML20005F1571990-01-0808 January 1990 LER 89-043-00:on 891208,discovered That Approx 50% of One Nut Ring Half Beneath Reactor Vessel Nozzle Flange Corroded Away.Caused by Gradual Deterioration of Gasket Matl.Design Change implemented.W/900108 Ltr ML20005F2071990-01-0404 January 1990 LER 89-040-00:on 891205 & 06,automatic Actuations of Emergency Diesel Generator Occurred as Result of Loss of Power to 480-volt ESF Bus.Caused by Personnel Error During Bus Transfer.Mgt Briefings conducted.W/900104 Ltr ML20005F0471990-01-0303 January 1990 LER 89-046-00:on 891204,reactor Bldg Isolation Valves Rendered Inoperable Due to Deficient Welds on Piping Supports Which Were Installed During Initial Plant Const. Deficient Supports Repaired Prior to restart.W/900103 Ltr ML20011D2521989-12-18018 December 1989 LER 89-039-00:on 891116,discovered That Door for Upper North Electrical Penetration Room Open & Missing Latch Mechanism. Caused by Extensive Use During 56-day Refueling Outage.More Frequent Insps of Door Condition to Be done.W/891218 Ltr ML20011D2501989-12-18018 December 1989 LER 89-023-00:on 891117,approach to Criticality Commenced After Seventh Refueling Outage W/Logarithmic Power Level Channels Inoperable.Caused by Electrical Noise in Circuitry. Defective Preamplifier replaced.W/891218 Ltr ML19351A6731989-12-14014 December 1989 LER 89-022-00:on 891114,inadequate post-maint Test Controls Resulted in de-energizing 4,160 Volt Ac ESFs Electric Bus Uexpectedly.Caused by Inadequate post-maint Test Controls. Job Order Instructions changed.W/891214 Ltr ML19354D5521989-12-14014 December 1989 LER 89-038-00:on 891114,reactor Trip Occurred as Result of Inadvertent Closure of Main Feedwater Isolation Valve.Caused by Personnel Error.Disciplinary Action Taken Against Individual & Senior Mgt Personnel Put on shift.W/891214 Ltr ML19351A4651989-12-11011 December 1989 LER 89-021-00:on 891111,when Low Level Radwaste Water in Waste Condensate Tank Aligned to Be Released,Discovered That Radiation Monitor Inoperable for Duration of Release.Caused by Personnel Error.Procedure revised.W/891211 Ltr ML19332F6171989-12-11011 December 1989 LER 89-037-00:on 891110,reactor Trip Occurred as Result of Inadvertent Grounding of Reactor Protection Sys Power Supply During Surveillance Testing.Caused by Inadequate Procedure. Procedures revised.W/891211 Ltr ML20005D6821989-12-0101 December 1989 LER 89-005-01:on 890518 & 25,damping Board Removed from Penetration Containing Cable Tray.On 890531,voids Noted in Penetration Seals.Caused by Erroneous Vendor Procedures. Penetrations Restored & Procedures revised.W/891201 Ltr ML19332E8611989-11-30030 November 1989 LER 89-034-00:on 891031,control Room Emergency Air Conditioning Sys Rendered Inoperable Due to Removing Independent Circuits from Svc.Caused by Inadequate Guidance.Procedures Revised & Circuits flagged.W/891130 Ltr 1998-10-22
[Table view] Category:RO)
MONTHYEARML17335A7641998-10-22022 October 1998 LER 98-004-00:on 980923,inadvertent Actuation of Efs Occurred During Surveillance Testing.Caused by Personnel Error.Personnel Involved with Event Were Counseled & Procedure Changes Were Implemented.With 981022 Ltr ML20045B3021993-06-11011 June 1993 LER 93-001-00:on 930513,discovered That One Channel of Rvlms Inoperable Since Probe Replaced in Oct 1992.On 930507, Discovered That Two Sensors in Rvlms Indicating Wet.Caused by Design Error.Wiring Polarity corrected.W/930611 Ltr ML20024H2281991-05-21021 May 1991 LER 91-003-00:on 910421,actuation of EFW Sys During Plant Heatup Occurred Due to Low Once Through Steam Generator Level.Caused by Leaking Feedwater Recirculation Valve.Plant Startup Procedure OP 1102.02 Will Be revised.W/910521 Ltr ML20024H0861991-05-10010 May 1991 LER 91-002-00:on 910410,inadvertent Actuations of Combined Control Emergency Ventilation Sys Occurred.Caused by Transient Noise Spike.Mod Will Be Completed by 910531 to Install Time Delay in Actuation circuitry.W/910510 Ltr ML20024G9781991-05-10010 May 1991 LER 90-004-01:on 900531,discovered Degraded Fire Barrier Penetration During Insp Per Generic Ltr 86-10.Caused by Failure to Identify Adequate Fire Barrier Seal During 1983 Plant Walkdown.Fire Watch posted.W/910510 Ltr ML20029C3771991-03-22022 March 1991 LER 91-006-00:on 910222,core Protection Calculator Reactor Coolant Sys Flow Channels Not Being Calibrated within Tech Spec.Caused by Personnel Error.Operations Manager Counseled Operators Involved in event.W/910322 Ltr ML20029B1331991-02-27027 February 1991 LER 91-004-00:on 910125,control Room Radiation Monitor Alarm/Trip Setpoint Greater than Normal.Caused by Personnel Error.Operations Manager Will Counsel Shift Supervisors & Night Order Will Be posted.W/910227 Ltr ML20028H6841991-01-21021 January 1991 LER 90-021-00:on 901222,potential RCS Leak Noted in Area of Pressurizer Upper Level Instrument Nozzle.Caused by Pure Water Stress Corrosion Cracking.New Nozzle Installed Into Penetration from Shell OD.W/910121 Ltr ML20043C6801990-05-31031 May 1990 LER 89-025-01:on 891221,identified That Portion of Wall Located in Auxiliary Bldg Had Not Been Previously Identified as Tech Spec Fire Barrier.Caused by Personnel Error.Wall Being Upgraded to Tech Spec status.W/900531 Ltr ML20043C3781990-05-30030 May 1990 LER 90-012-00:on 900430,18 Month Channel Calibr of Liquid Radwaste Effluent Line Flow Monitor Not Performed as Required.Caused by Inadequate Controls to Ensure Followup Actions Taken in Timely Manner.Amends revised.W/900530 Ltr ML20043C0361990-05-23023 May 1990 LER 90-003-01:on 900423,discovered That Incorrect Monitoring Instrumentation for Radiological Effluent Ventilation Sys Utilized to Comply W/Tech Specs.Caused by Mgt Oversight.Logs Process Monitors Will Not Be used.W/900523 Ltr ML20043A7411990-05-17017 May 1990 LER 90-004-01:on 900212,discovered That Backwater Valve in Floor Drain Pipe in Emergency Feedwater Pump Room Missing. Caused by Inadequate Configuration Control.Backwater Pumps Installed & Will Be Included in Maint program.W/900517 Ltr ML20042F7681990-05-0101 May 1990 LER 90-002-01:on 900131,errors Identified in Calculation Used to Establish Calibr Tables for Steam Generator Water Level Transmitters.Errors in Original Calculation Not Identified.Calibr Procedures revised.W/900501 Ltr ML20042F7751990-05-0101 May 1990 LER 90-010-00:on 900401,personnel Failed to Complete Control Element Assembly Position Log.Caused by Surveillance Program Deficiencies & Lack of Mgt Involvement.Shift Briefing Completed & Procedure Change incorporated.W/900501 Ltr ML20042E1981990-04-10010 April 1990 LER 90-008-00:on 900311,determined That Seal Leakage Test for Containment Personnel Air Lock Had Not Been Performed, Per Tech Specs.Caused by Personnel Error.Procedure Revs Initiated & Personnel counseled.W/900410 Ltr ML20012F5051990-04-0505 April 1990 LER 89-027-00:on 891005,determined That Leakage Rate for Containment Isolation Check Valve in Excess of Leakage Rate Allowed Per Tech Specs.Caused by Loose Weld Slag in Valve Seat Area.Valve Cleaned & reassembled.W/900405 Ltr ML20012F5031990-04-0505 April 1990 LER 90-007-00:on 900306,RCS Charging Line Rendered Inoperable Due to Deficient Piping Support Weld.Caused by Inadequate Work Controls & post-installation Insp Processes. Field Walkdowns & Weld Insps initiated.W/900405 Ltr ML20012F5741990-04-0404 April 1990 LER 90-006-00:on 900305,instrumentation Channels Declared Inoperable,Resulting in Manual Actuation of Reactor Protection Sys.Caused by Procedural Deficiencies.Functional Tests of Log Power Level Channels performed.W/900404 Ltr ML20012C7221990-03-14014 March 1990 LER 90-004-00:on 900212,identified That No Backwater Valve Located in Floor Drain Pipe in One of Emergency Feedwater Pump Rooms.Caused by Inadequate Configuration Control. Valves Installed on 900215.W/900314 Ltr ML20012C1821990-03-12012 March 1990 LER 85-029-00:on 850520,unusual Motor Vibrations Identified on Svc Water Pump 2PM4A.On 861028,high Vibrations Noted on Upper Motor Bearings of Pump 2PM4B.Caused by Improper Installation.New Bearings installed.W/900312 Ltr ML20012B7271990-03-0808 March 1990 LER 89-049-01:on 891220,discovered That Okonite T-95 Tape Not Used to Tape Internal Motor Lead Connections for Main Feedwater Containment Isolation Valves.Caused by Personnel Error.Valves Taped According to Design drawing.W/900308 Ltr ML20012B5701990-03-0505 March 1990 LER 90-003-00:on 900201,failure to Perform Monthly Source Check Surveillance on Three Radiation Process Monitors Occurred.Caused by Inadequate Procedure Change by Personnel. Source Check on Monthly Basis implemented.W/900305 Ltr ML20011F6741990-03-0202 March 1990 LER 90-002-00:on 900131,errors Identified in Calculation Used to Establish Calibr Tables for Steam Generator Water Level Transmitters.Caused by Incorrect Static Pressure Assumption.Trip Setpoint Bistable increased.W/900302 Ltr ML20011F6781990-03-0101 March 1990 LER 89-026-00:on 891112,gaps in Piping Supports on Supply & Return Piping for Containment Coolers Identified.Caused by Inadequate Design Technique Used in Original Support Design. Shims Added Before Restart from outage.W/900301 Ltr ML20011F5831990-02-27027 February 1990 LER 89-022-01:on 891114,normal Offsite Power Feeder Breaker to 4,160-volt Ac ESF Bus Opened,Resulting in Loss of Power to Bus 2A3.Caused by Inadequate post-maint Test Controls. Test Switch Opened & Job Order changed.W/900227 Ltr ML20011F7311990-02-23023 February 1990 LER 90-001-00:on 900126,identified That Required Visual Insps of Containment Bldg After Entry Made Not Documented as Being Performed.Caused by Inadequate Procedural Guidance. Administrative Controls to Be established.W/900226 Ltr ML20006D7391990-02-0606 February 1990 LER 89-034-01:on 891031,determined That Tech Spec 3.9.1 Had Likely Been Violated Re Independent Circuits of Control Room Emergency Air Conditioning Sys.Caused by Inadequate Guidance Re Equipment Svc Removal.Procedures revised.W/900206 Ltr ML20011E2371990-01-31031 January 1990 LER 89-012-01:on 890626,RCS Backleakage Through Safety Injection Sys Check Valve Occurred Three Times.Caused by Missing Rollpins Which Connect Valve Disc to Valve Disc Shaft.Rollpins Replaced & Valves reassembled.W/900131 Ltr ML20011E2291990-01-31031 January 1990 LER 89-039-01:on 891116,discovered That Door for Upper North Electrical Penetration Room Open & Latch Mechanism Missing. Caused by Abnormally High Differential Pressure Across Door. Ventilation Sys Flow Balance performed.W/900131 Ltr ML20011E1451990-01-30030 January 1990 LER 89-024-00:on 891231,loose Terminal in Feedwater Control Sys Cabinet Resulted in Reactor Trip.Caused by Loose Connection on Terminal.Loose Connection Reterminated properly.W/900130 Ltr ML20006C1451990-01-29029 January 1990 LER 89-048-00:on 891228,automatic Reactor Trip & ESF Actuation Occurred as Result of Loss of All Main Feedwater Flow Due to Inadvertent Tripping of Main Feedwater Pump. Caused by Personnel error.O-rings replaced.W/900129 Ltr ML19354E3331990-01-22022 January 1990 LER 89-025-00:on 891221,two Piping Penetrations Located in Barrier Not Surveilled as Required by Tech Specs.Caused by Personnel Error.Fire Watch Posted When Necessary Per Tech Spec.W/900122 Ltr ML20006A8661990-01-22022 January 1990 LER 89-041-00:on 891221,automatic Actuation of Emergency Feedwater Sys Initiated.Caused by Lack of Adequate Procedural Guidance.Valve Positioners CV-2623 & CV-2673 Adjusted & Guidance Procedures developed.W/900122 Ltr ML20006A8671990-01-22022 January 1990 LER 89-042-01:on 891209,inadvertent Actuation of Control Room Emergency Ventilation Sys Occurred.Caused by Keying of Hand Held Radio in Vicinity of Chlorine Monitors by Technician.Technician counseled.W/900122 Ltr ML20005F1551990-01-18018 January 1990 LER 89-023-01:on 891117,noted That Channel a Not Responding to Change in Power Level & Declared Inoperable.Caused by Defective Preamplifier.Evaluation of Sys Design & Channel Functional Test initiated.W/900108 Ltr ML20006B6461990-01-18018 January 1990 LER 89-047-00:on 891219,RCS Temp Increased Above 250 F W/ Oxygen Concentration Greater than Tech Specs Limit.Caused by Inadequate Procedural Guidance.Plant Startup Procedure Revised to Require Chemistry Dept signoff.W/900118 Ltr ML19354D8291990-01-15015 January 1990 LER 89-044-00:on 891214,incorrect Assumptions & Calculational Errors Identified for Low Pressure Injection & Reactor Bldg Spray Pumps When Aligned to Take Suction from Reactor Bldg sump.W/900115 Ltr ML20005G1681990-01-0909 January 1990 LER 89-045-00:on 891210,discovered That U-bolt Supports on Two Containment Isolation Valves in Containment Bldg Not Installed & Pressurizer Sample Lines & Valves Considered Inoperable.Missing U-bolts installed.W/900109 Ltr ML20005F1481990-01-0808 January 1990 LER 89-042-00:on 891209,inadvertent Actuation of Control Room Emergency Ventilation Sys Occurred.Caused by Keying of Hand Held Radio in Vicinity of Chlorine Monitors by Technician.Technician counseled.W/900108 Ltr ML20005F1571990-01-0808 January 1990 LER 89-043-00:on 891208,discovered That Approx 50% of One Nut Ring Half Beneath Reactor Vessel Nozzle Flange Corroded Away.Caused by Gradual Deterioration of Gasket Matl.Design Change implemented.W/900108 Ltr ML20005F2071990-01-0404 January 1990 LER 89-040-00:on 891205 & 06,automatic Actuations of Emergency Diesel Generator Occurred as Result of Loss of Power to 480-volt ESF Bus.Caused by Personnel Error During Bus Transfer.Mgt Briefings conducted.W/900104 Ltr ML20005F0471990-01-0303 January 1990 LER 89-046-00:on 891204,reactor Bldg Isolation Valves Rendered Inoperable Due to Deficient Welds on Piping Supports Which Were Installed During Initial Plant Const. Deficient Supports Repaired Prior to restart.W/900103 Ltr ML20011D2521989-12-18018 December 1989 LER 89-039-00:on 891116,discovered That Door for Upper North Electrical Penetration Room Open & Missing Latch Mechanism. Caused by Extensive Use During 56-day Refueling Outage.More Frequent Insps of Door Condition to Be done.W/891218 Ltr ML20011D2501989-12-18018 December 1989 LER 89-023-00:on 891117,approach to Criticality Commenced After Seventh Refueling Outage W/Logarithmic Power Level Channels Inoperable.Caused by Electrical Noise in Circuitry. Defective Preamplifier replaced.W/891218 Ltr ML19351A6731989-12-14014 December 1989 LER 89-022-00:on 891114,inadequate post-maint Test Controls Resulted in de-energizing 4,160 Volt Ac ESFs Electric Bus Uexpectedly.Caused by Inadequate post-maint Test Controls. Job Order Instructions changed.W/891214 Ltr ML19354D5521989-12-14014 December 1989 LER 89-038-00:on 891114,reactor Trip Occurred as Result of Inadvertent Closure of Main Feedwater Isolation Valve.Caused by Personnel Error.Disciplinary Action Taken Against Individual & Senior Mgt Personnel Put on shift.W/891214 Ltr ML19351A4651989-12-11011 December 1989 LER 89-021-00:on 891111,when Low Level Radwaste Water in Waste Condensate Tank Aligned to Be Released,Discovered That Radiation Monitor Inoperable for Duration of Release.Caused by Personnel Error.Procedure revised.W/891211 Ltr ML19332F6171989-12-11011 December 1989 LER 89-037-00:on 891110,reactor Trip Occurred as Result of Inadvertent Grounding of Reactor Protection Sys Power Supply During Surveillance Testing.Caused by Inadequate Procedure. Procedures revised.W/891211 Ltr ML20005D6821989-12-0101 December 1989 LER 89-005-01:on 890518 & 25,damping Board Removed from Penetration Containing Cable Tray.On 890531,voids Noted in Penetration Seals.Caused by Erroneous Vendor Procedures. Penetrations Restored & Procedures revised.W/891201 Ltr ML19332E8611989-11-30030 November 1989 LER 89-034-00:on 891031,control Room Emergency Air Conditioning Sys Rendered Inoperable Due to Removing Independent Circuits from Svc.Caused by Inadequate Guidance.Procedures Revised & Circuits flagged.W/891130 Ltr 1998-10-22
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217L8931999-10-31031 October 1999 Rev 1 to BAW-10235, Mgt Program for Volumetric Outer Diameter Intergranular Attack in Tubesheets of Once-Through Sgs ML20212L1141999-10-0101 October 1999 Safety Evaluation Granting Request for Exemption from Technical Requirements of 10CFR50,App R,Section III.G.2.c 0CAN109902, Monthly Operating Repts for Sept 1999 for Arkansas Nuclear One,Units 1 & 2.With1999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Arkansas Nuclear One,Units 1 & 2.With ML20216J6271999-09-27027 September 1999 Rev 0 to CALC-98-R-1020-04, ANO-1 Cycle 16 Colr ML20212F5261999-09-22022 September 1999 SER Approving Request Reliefs 1-98-001 & 1-98-200,parts 1,2 & 3 for Second 10-year ISI Interval at Arkansas Nuclear One, Unit 1 0CAN099907, Monthly Operating Repts for Aug 1999 for Ano,Units 1 & 2. with1999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Ano,Units 1 & 2. with ML20211F4281999-08-25025 August 1999 Safety Evaluation Concluding That Licensee Provided Acceptable Alternative to Requirements of ASME Code Section XI & That Authorization of Proposed Alternative Would Provide Acceptable Level of Quality & Safety 0CAN089904, Monthly Operating Repts for July 1999 for Ano,Units 1 & 2. with1999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Ano,Units 1 & 2. with ML20210K8831999-07-29029 July 1999 Non-proprietary Addendum B to BAW-2346P,Rev 0 Re ANO-1 Specific MSLB Leak Rates 0CAN079903, Monthly Operating Repts for June 1999 for Ano,Units 1 & 2. with1999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Ano,Units 1 & 2. with ML20207E7231999-06-0202 June 1999 Safety Evaluation Authorizing Proposed Alternative Exam Methods Proposed in Alternative Exam 99-0-002 to Perform General Visual Exam of Accessible Areas & Detailed Visual Exam of Areas Determined to Be Suspect ML20196A0191999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Arkansas Nuclear One,Units 1 & 2.With ML20196A6251999-05-31031 May 1999 Non-proprietary Rev 0 to TR BAW-10235, Mgt Program for Volumetric Outer Diameter Intergranular Attack in Tubesheets of Once-Through Sgs ML20195D1991999-05-28028 May 1999 Probabilistic Operational Assessment of ANO-2 SG Tubing for Cycle 14 ML20206M7711999-05-11011 May 1999 SER Accepting Relief Request from ASME Code Section XI Requirements for Plant,Units 1 & 2 0CAN059903, Monthly Operating Repts for Apr 1999 for Ano,Units 1 & 2. with1999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Ano,Units 1 & 2. with ML20206F0691999-04-29029 April 1999 Safety Evaluation Accepting Licensee Re ISI Plan for Third 10-year Interval & Associated Requests for Alternatives for Plant,Unit 1 ML20205M6941999-04-12012 April 1999 Safety Evaluation Granting Relief for Second 10-yr Inservice Inspection Interval for Plant,Unit 1 ML20205D6061999-03-31031 March 1999 Safety Evaluation Supporting Licensee Proposed Approach Acceptable to Perform Future Structural Integrity & Operability Assessments of Carbon Steel ML20205R6351999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Ano,Units 1 & 2. with ML20205D4711999-03-26026 March 1999 SER Accepting Util Proposed Alternative to Employ Alternative Welding Matls of Code Cases 2142-1 & 2143-1 for Reactor Coolant System to Facilitate Replacement of Steam Generators at Arkansas Nuclear One,Unit 2 ML20204B1861999-03-15015 March 1999 Safety Evaluation Authorizing Licensee Request for Alternative to Augmented Exam of Certain Reactor Vessel Shell Welds,Per Provisions of 10CFR50.55a(g)(6)(ii)(A)(5) 0CAN039904, Monthly Operating Repts for Feb 1999 for Ano,Units 1 & 2. with1999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Ano,Units 1 & 2. with ML20212G6381999-02-25025 February 1999 Ano,Unit 2 10CFR50.59 Rept for 980411-990225 ML20203E4891999-02-11011 February 1999 Rev 1 to 97-R-2018-03, ANO-2,COLR for Cycle 14 ML20199F0351998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Ano,Units 1 & 2 ML20198M7841998-12-29029 December 1998 SER Accepting Util Proposal to Use ASME Code Case N-578 as Alternative to ASME Code Section Xi,Table IWX-2500 for Arkansas Nuclear One,Unit 2 0CAN129805, LER 98-S02-00:on 981124,security Officer Found Not to Have Had Control of Weapon for Period of Approx 3 Minutes Due to Inadequate self-checking to Ensure That Weapon Remained Secure.All Security Officers Briefed.With1998-12-11011 December 1998 LER 98-S02-00:on 981124,security Officer Found Not to Have Had Control of Weapon for Period of Approx 3 Minutes Due to Inadequate self-checking to Ensure That Weapon Remained Secure.All Security Officers Briefed.With ML20196F4911998-12-0101 December 1998 SER Accepting Request for Relief ISI2-09 for Waterford Steam Electric Station,Unit 3 & Arkansas Nuclear One,Unit 2 ML20198D2441998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Ano,Units 1 & 2. with ML20199F7401998-11-16016 November 1998 Rev 9 to ANO-1 Simulator Operability Test,Year 9 (First Cycle) ML20195B4801998-11-0707 November 1998 Rev 20 to ANO QA Manual Operations ML20195C4841998-11-0606 November 1998 SER Accepting QA Program Change to Consolidate Four Existing QA Programs for Arkansas Nuclear One,Grand Gulf Nuclear Station,River Bend Station & Waterford 3 Steam Electric Station Into Single QA Program 0CAN119808, Monthly Operating Repts for Oct 1998 for Ano,Units 1 & 2. with1998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Ano,Units 1 & 2. with ML20197H0741998-10-29029 October 1998 Rev 1 to Third Interval ISI Program for ANO-1 ML20155C1351998-10-26026 October 1998 Rev B to Entergy QA Program Manual ML17335A7641998-10-22022 October 1998 LER 98-004-00:on 980923,inadvertent Actuation of Efs Occurred During Surveillance Testing.Caused by Personnel Error.Personnel Involved with Event Were Counseled & Procedure Changes Were Implemented.With 981022 Ltr ML20154J2471998-10-0909 October 1998 SER Accepting Inservice Testing Program,Third ten-year Interval for License DPR-51,Arkansas Nuclear One,Unit 1 0CAN109806, Monthly Operating Repts for Sept 1998 for ANO Units 1 & 2. with1998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for ANO Units 1 & 2. with ML20154E2171998-09-28028 September 1998 Follow-up Part 21 Rept Re Defect with 1200AC & 1200BC Recorders Built Under Westronics 10CFR50 App B Program. Westronics Has Notified Bvps,Ano & RBS & Is Currently Making Arrangements to Implement Design Mods 0CAN099803, Monthly Operating Repts for Aug 1998 for ANO Units 1 & 2. with1998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for ANO Units 1 & 2. with ML20237B7671998-08-19019 August 1998 ANO REX-98 Exercise for 980819 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 ML20236X2351998-08-0505 August 1998 Part 21 Rept Re Defect Associated W/Westronics 1200AC & 1200BC Recorders Built Under Westronics 10CFR50,App B Program.Beaver Valley,Arkansas Nuclear One & River Bend Station Notified.Design Mod Is Being Developed 0CAN089804, Monthly Operating Repts for July 1998 for Ano,Units 1 & 21998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Ano,Units 1 & 2 ML20196C7831998-07-30030 July 1998 Summary Rept of Results for ASME Class 1 & 2 Pressure Retaining Components & Support for ANO-1 ML20155H7161998-07-15015 July 1998 Rev 1 to 96-R-2030-02, Revised Reactor Vessel Fluence Determination ML20236R0531998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Ano,Units 1 & 2 ML20249B7791998-06-22022 June 1998 Part 21 Rept Re Findings,Resolutions & Conclusions Re Failure of Safety Related Siemens 4KV,350 MVA,1200 a Circuit Breakers to Latch Closed ML20249B5091998-06-15015 June 1998 SG ISI Results for Fourteenth Refueling Outage 1999-09-30
[Table view] |
Text
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f Artcnsas P wer & Light Company p.j ' Je .; , Arkansa', Nuclear One
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January 4,1990 ,
ICAN519804 n
U.S. Nuclear Regulatory Commission Document Control Desk
/ Mai1L$tation PI-137
= Wast-ington, D.C. 20555 SUBJECI': Arkansas Nuclear.One - Unit 1 Docket No. 50-313 i
- s. License No. DPR-51 Licensee Event Report No. 50-313/89-040-00 Gentlemen:
In accordar.ce with 10CFR50.73(a)(2)(iv), attached is the subject report concerning two Emergency. Diesel Generator actuations which occurred due to loss oi' power to a 480 volt Engineered Safeguards bus caused by personnel
. error.
Very truly yours,
/ ,
E. C. Ewing General-Manager, Technical Support and Assessment ECE/RHS/sgw attachment cc: Regional Administrator Region IV i U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 l
INPO Records Center 1500 Circle 75 Parkway
- l. Atlanta, GA 30339-3064 L
9001160051 993104 PDR ADOCK 05000313 PDC
[p S ,,
.. An Ente <gy Company
~~ , .. . - - .- - .
, , Ptem 1062.01 A NRC Form 366s U.S. Nuclear Regulatory Commission +
(D-83) Approved DMB No. 3150-0104 Empires: 8/31/85 LICEN$EE EVENT REP 0RT (L E R) -
FACILITY NAME (1) Arkansas Nuclear One Unit One IDOCKET NUMBER (2) IPAGE (3) 10151010101 31 11 31110Flol4 TITLE (4) Two Emergency Dieset Generator Actuations Due to Loss of Power to a 480V Engineered safeguards Bus caused By Personnel Error EVENT DATE (5) I LER NUMBER (6) i REPORT DATE (7) l OTHER FACILtTIES INVOLVED (8) l l l l 15equentiell IRevisioni i l i l Monthi Day lYear lYear i I Number I i humber IMonthi Day lYear i Facility Names IDocket Number (s) l l l l l l .1 l l l l 10151010101 I l ,
Il 21 01 $l Bf 91 81 91--I O l'41 0 l--I O I O I of II 01 41 91 01 10151010101 1 1 OPERATING l lTHis REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR B:
MDDE (9) i Ni (Check one or more of the fo110winn) (11)
POWERI l._I 20.402(b) 1 _t 20.405(c) l_El 50.73(a)(2)(iv) 1 _t 73.71(b)
LEVEll l__l 20.405(a)(1)(1) I,_,1 50.36(c)(1) l__l 50.73(a)(2)(v) l__l 73.71(c)
(10) 1010101 1 20.405(a)(1)(11) I,_,1 50.36(c)(2) 1._l 50.73(a)(2)(v11) l__l Other (Specify in l__l 20.405(a)(1)(iii) l__l 50.73(a)(2)(1) 1 _l 50.73(a)(2)(v111)(A)l Abstract below and
, l__l 20.405(a)(1)(tv) l__l 50.73(a)(2)(11) 1._I 50.73(a)(2)(viii)(B)l in Text, NRC Form t
l I I 20.405(a)(1)(v) I I 50.73:o)(2)(111) I i 10.73(a)(2)(x) I' 366A)
LICENSEE CONTACT FOR THl$ L !R (12) home i Teleohone Number lArea i Larry A. Taylor, Nuclear Safety and Licensing Specialist ICode i 1510111916141-13111010 CONPLETE ONE LINE FOR EACH CDNPONENT FAILURE DESCRIBED IN THIS REPORT (13)
. l l l lReportabiel l l l l lReportablel r Causelsysteel Conoonent IManufacturerl to NPRDS I ICausel5ysteel Component IManufacturerl to NPRDS I i 1- l- 1 l l l l l l l l l 1 I l I i l i l ! I I I I I I l I i i i I I I l 1 i i l l 1 i l 1 1 ,
l l l i I ~ l i I1 I I l I l l I I I i l l i I I l 1 SUPPLEMENT REPORT EXPECTED (14) l EXPECTED l Monthi Day lYear
~ _ l SUBMISSION l i l l l Yes (If ves, complete Expected Subsission Date) Ik l No l DATE (15) l I I i 1 1 ABSTRACT (Lielt to 1400 spaces,1.e. , approximately fif teen single-space typewritten lines) (16)
On December 5, 1989 at 0645 and December 6, 1989 at 2205, while the plant was shutdown in a maintenance i outage, automatic actuations of an Emergency Diesel Generator (EDG) occurred as a result of loss of '
power to a 480 volt (v) Engineered Safeguards (ES) bus. Prior to both events, the 85 and B6 480v E5 busses were crossconnected to facilitate maintenance activities. The December 5 event occurred as a result of a personnel error which occurred while operators were attempting to "splitout" the 85 and B6 busses and return the ES power distributtor< system lineup to normal. The error resulted in a loss of l Power to bus 86 which caused the offsite feeder breaker for 4.16 kilovolt bus A4 to open and initiated a start of the 'B' EDG which tied on to the A4 bus. The December 6 event was also the result of a l personnel error which caused a loss of power to 480v Es bus 85. This condition caused the offsite feeder breaker for A3 to trip and the ' A' EDG to start. The momentary loss of power to A3 caused the operating Decay Heat Removal (DHR) pump to trip. DHR flow was lost for approximately 9 einutes and resulted in a Reactor Coolant System temperature increase of 17 degrees. Management briefings were l conducted for the operating crews prior to restart from the outage covering the lessons learned froe
- these events. On-shift guidance with respect to management expectations regarding watchstanding professionalise and formality and attention to detail is also being provided.
l
. s Form 1062.01B NRC Form 366A U.S. Nuclear Regulatory Commission (9-83) : Approved DMB No. 3150-01D4 Expires: B/31/B5 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY NAME (1) l DOCKET NUMBER (2) l LER NUMBER (6) l PAGE (3) l l l 15equentiall (Revision l Arkansas Nuclear One, Unit One l l Yearl i Number 1 i Number l 10151010101 31 11 31 81 91--l 0141 01--I 0 1 0 101210Fl014 TEK1 (If more space is required, use additional NRC Form 366A's) (17)
A. Plant Status At the time of these events, Arkansas Nuclear One, Unit 1 (ANO-1) was in the cold shutdown condition.
Midcycle outage IMB9 was in progress.
B. Event Description Dn December 5,1989 at approximately 0645 hours0.00747 days <br />0.179 hours <br />0.00107 weeks <br />2.454225e-4 months <br />, while licensed plant operators were in the process of restoring the Engineered Safeguards (ES) electrical distribution system lineup to normal, a momentary loss of power to 4160V ES bus A4 and 480V ES bus B6 occcrred. The 'B' Emergency Diesel Generator (EDG) automatically started and raenergized bus A4.
The electrical distribution lineup prior to this event was as follows (see Figure 1): 4.16KV switchgear A3 was being powered from switchgear A1 (supplied by offsite power) and 4.16KV switchgear A4 was being supplied by A2. 480Y ES bus B5 was being supplied by A3 via circuit breakers A-301 and B-512, 480V ES bus 86 was crossconnected to 85 through circuit breakers B-513 and B-613. The feeder breakers from A4 to B6 (A 401, B-612) were open. The 'A' EDG was being run for surveillance testing and was tied to A3 and operating in parallel with the offsite power system. Decay Heat Removal (DHR) pump P-34A was in - '
service.
Three operators were involved in the bus transfer. It should be noted at this time that the normal feeder breakers to B5 and 86 (B-512 B-612) and the B5/86 crosstie breakers (B-513, B-613) are each electrically interlocked to trip when the otiier three are closed. The sequence of events leading up to the diesel start was as follows:
e Operator #1 closed the 4.16KV feeder breaker from A4 to 86 (A-401).
e Operator #2 held the handswitch for B-512 in the close position to prevent it from tripping due to the interlock discussed above. .
e Dperator #1 held the handswitches for B-513 and B-613 in the close position to prevent the inadvertent l loss of power to B6.
l
- Operator #3 closed the 480V feeder breaker from A-4 to B-6 (B-612) and held the switch in the close position.
I e Operator #1 then released the handswitches for B-513 and B-613.
When the switch for B-613 was released, breaker B-613 tripped, the 'B' EDG started automatically, the A2 to A4 feeder breaker (A-409) tripped, as designed, and the EDG tied to A4. At this time, the operators observed that the feeder breaker from A4 to B6 (A-401) was open with the handswitch in the I
normal after close position, indicating that the breaker had tripped. This resulted in completely doenergizing the B6 bus and initiating the EDG start due to an undervo?tage condition on 86. Since l
the operators did not know why A 401 had tripped, tt ey reestablished power to B6 from 85 by reclosing breaker B-613 and opening B-612. At 0700, the A2 supply to A4 was restored and the 'B' EDG was secured.
At 0745, the electrical distribution lineup was returned to a normal alignment (85 and 86 split).
A second inadvertent loss of power to a 480V E$ bus and subsequent EDG start occurred on December 6, l 1989 at approximately 2205.
l The electrical distribution lineup prior to this event was as follows. 480V E5 busses 85 and 86 were crossconnected through their respective crosstie breakers (B-513, B-613). 86 was being powered from 4.16KV bus A4 through faeder breakers A-401 and B-612. The A3 to B5 feeder breakers (A-301 and B-512) were open, racked down and tagged out to allow inspection of 4.16KV/480Y transformer X5. DHR pump P-34A was in service.
After completion of the transformer inspection, a plant auxiliary operator was instructed to go to the A3 switchgear room and remove the hold cards from breaker A-301 and B-512 and rack in the breakers in preparation for closing the breakers. Af ter racking in the breakers, the operator was in the process of charging the springs for breaker B-512 when it inadvertently closed and immediately reopened. At this time the B6 crosstie breaker (B-613) opened, since it is interlocked with B-512, B-513 and B-612
4: .
Form 1062.018
- Nic Fom 366A U.S. Nuclear Regulatory Commission (9-83) Approved Ope No. 3,150-0104 Empires 8/31/85 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION
- FACILITY N M (1) l DOCKET NUISER (2) l LER NupeER (6) l PAGE (3) l l l 15equentiell l Revision!
Arkansas Nuclear One, Unit Dne l l Yearl l Number l l Number l 101510f0f01 31 Il 31 el 91--I of 41 01--I 01 Ol01310Flol4 TEXT (if more space is required, use soditional NRC Fom 366A's) (17) to open when the other three are closed. The tripping of breaker B-613 caused a loss of power to bus 95 which initiated an autostart of the 'A' EDG due to undervoltage on 85. The Al to A3 feeder breaker tripped, as designed, and the EDG output breaker closed, reenergizing bus A3. The momentary loss of power to 4.16KY bus A-3 caused the breaker for DHR psamp P-34A to trip, resulting in a loss of DMR flow. The operators immediately reenergized bus 95 from A3 by closing breakers A-301 and B-512. '
At approximately 2210, bus A3 was paralleled to Al and the EDG was secured. At 2214. DHR pump P-34A was restarted and DHR flow was mestablished. DHR cooling flow had been interrupted for approximately 9 minutes. During this time Reactor Coolant System (RCS) [AB) temperature increased from 103 degrees to 120 aegrees.
C. Safety Significance The EDGs response to the loss of power to the E5 bus during both events was as designed. All interlocks and breakers functioned as required. During the first event, the operating DHR pump (P-34A) was being powered from A3 and the momentary loss of power to A4 did not cause a loss of DHR flow. However, during the second event, DHR flow was lost for approximately nine minutes Msulting in an increase in pCS temperature of approximately seventeen degrees. Although the DHR pump was available for restart famediately after tripping, decay heat loads were such that it was not necessary to restart the pump until the electrical distribution lineup was nomalized. Considering that DHR cooling was reestablished expeditiously and that the EDGs responded properly during these events, their safety significance is considered minimal.
D. Root Cause In an effort to determine the causes of the two events discussed in this report, an evaluation of the design of the 480V E5 bus tie and feeder breakers was conducted. This evaluation verified that there were no design deficiencies which could have caused or contributed to the events. Additionally, functional testing of the involved breakers was perfomed which verified that all the breakers operated as designed.
L The exact cause of why breaker A-401 was either open or tripped during the first event or why breaker B-512 inadvertently closed during the second event could not be detemined. However, since the breaker design was verified to be correct and the breakers were proven t5 be operable, the most likely cause of these events is considered to be personnel error during the bus transfer evolutions.
i E. Basis for Reportability These events are reportable in accordance with 10CFR50.73(a)(2)(iv), as automatic actuations of an Engineered Safety Feature.
F. Corrective Actions A senior management evaluation of these events determined that increased emphasis needed to be placed
- on watchstanding professionalism and formality. Management briefings were conducted for operating crews prior to restart from outage 1M89 covering the results of this evaluation.
Additionally, senior management and supervisory personnel are providing on-shift guidance to shif t personnel. This guidance includes management expectations regarding watchstanding professionalism
, and formality, attention to detail, procedure compliance and safety.
I A review of operating procedures will be conducted to evaluate the need to require sign-off steps when crossconnecting or restoring E5 electrical busses to nomal configuration while shutdown, and to determine if additional procedural enhancements are necessary. This review is expected to be completed by March 31, 1990.
During the next Requal Cycle, training will be provided on 480V breaker operations and on 85 - 86 breaker interlocks. This training is expected to be completed by March 31, 1990.
G. Additional Information There have been no previous EDG actuations caused by personnel error reported.
Energy Industry Identification System (EIIS) codes are indicated in the text as [XX).
r' 1, . . . .
l Fore 1062.018
' i Nilt Fors 366A- U.S. Nuclear Regulatory Commission I: (9 83) Approved Ole No. 3150-0104 -
Empires: 8/31/85 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY NAME (1) l DOCKET NUDGER (2) l LER NupeER (6) l PAGE (3)~
l l l lSequentiall l Revision!
' Arkansas Nuclear One, Unit One l l Yearl l Number l l Number l 10151010101 31 11 31 81 91--I 01 41 OI--I 01 0101410F1014 l TEXT (If more space is required, use additional NRC Fors 366A's) (17)
E FIGURE 1 SIMPLIFIED SCHEMATIC OF ES ELECTRICAL DISTRIBUTION SYSTEM t
EDG ' A. FROM 4160V , FROM 41s0V EDG 'B' SWOR 'A1' sWOR 'A2' A300 A408 I
4.1sMV sWOR 'A3'(Es) Y usMv sWaa A< <Es>
L yg A A g s
'A301 A305 A309 A409 A405 A401 V y V l VMw ,.. A ,,,, <===* t >=i =>
c ETIIII III' '1T1 Ik B812 Sei2 T esov Es Sus 'Bs' esov as Sus se' A
3813 B413 i/
1 --_ _ _ _ - _ _ _____ - _- _ _ _ _ - _ _ _ - _ - _ - _ .
_ - . . - .