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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20024J3211994-10-0505 October 1994 LER 94-006-00:on 940909,failure to Perform Slave Relay Test Associated W/One Containment Isolation Valve Due to Improper Work Practices.Reviewed All Slave Relay Test Procedures & Trained All Qualified reviewers.W/941005 Ltr ML20046B5251993-08-0404 August 1993 LER 93-007-00:on 930705,TS Required Surveillance Was Not Performed Because of Inappropriate Action Because of Lack of Attention to Detail.Generated WO 93047633 to Perform Required Surveillance on Unit 1 IPE CA 9010.W/930729 Ltr ML20045H9821993-07-12012 July 1993 LER 93-005-00:on 930612,manual Rt in Unit 1 Occurred Due to Equipment Failure Due to Failure of L-13 Field Cable Between Data Cabinet B & Bulkhead for Undetermined Reasons.Replaced Field cable.W/930709 Ltr ML20045D9681993-06-25025 June 1993 LER 93-006-00:on 930526,discovered That Sample Blower for Radiation Monitor 1 EMF-43B Off & Monitor Declared Inoperable & Ventilation Sys Air Intakes Not Isolated.Caused by Deficient Procedures.Test Procedures Revised ML20045B2811993-06-11011 June 1993 LER 93-004-00:on 930513,both Trains of CR Ventilation Sys Declared Inoperable Due to Equipment Failure.Exact Cause of Failure Could Not Be Determined.Train B Nuclear Svc Water Sys Flow Balance completed.W/930611 Ltr ML20029C2091991-03-21021 March 1991 LER 91-003-00:on 910219,both Trains of Control Room Ventilation Sys Inoperable.Caused by Design Malfunction & Management Deficiency.Temporary Modifications,Removing Automatic Closure Function implemented.W/910321 Ltr ML20028G9561990-09-26026 September 1990 LER 90-025-00:on 900827,Unit 1 Shut Down Because of Unidentified RCS Leakage Exceeding Tech Spec Limits.Caused by Equipment Failure.Procedure AP/1/A/5500/10 Implemented. Valve 1NC-33 Will Be Repacked at Next outage.W/900926 Ltr ML20044A0091990-06-25025 June 1990 LER 90-015-00:on 900524,Tech Spec 3.0.3 Entered Because More than One Power Range Nuclear Instrumentation Channel Exceeded 5% Deviation.Caused by Mgt Deficiency.Boric Acid Added to Coolant sys.W/900625 Ltr ML20043H4991990-06-21021 June 1990 LER 90-012-00:on 900522,loose Matl,Consisting of Masslin Cloths & Stepoff Pad,Discovered in Upper Containment.Caused by Failure to Follow Procedures.Loose Items Removed & Cleanliness Procedures revised.W/900621 Ltr ML20043H2641990-06-20020 June 1990 LER 90-011-00:on 900521,noted That Valve 1RN-69A Auxiliary Feedwater Assured Supply from Train a Nuclear Svc Water Repositioned to Open Position After Start of Pump.Cause Unknown.Pump Shut Down & Valve closed.W/900620 Ltr ML20043F7471990-06-13013 June 1990 LER 90-010-00:on 900427,discovered That Annulus Ventilation & Control Room Ventilation Sys Headers Would Not Operate,As Designed,Under Postulated Operating Conditions. Caused by Design Deficiency.Change submitted.W/900613 Ltr ML20043F5071990-06-11011 June 1990 LER 90-009-00:on 900512,feedwater Isolation Occurred as Result of Steam Generator 1B Reaching hi-hi Level Setpoint of 82% Level.Caused by Inappropriate Action Because of Lack of Attention to Detail.Feedwater Logic reset.W/900611 Ltr ML20043D6541990-05-30030 May 1990 LER 90-007-00:on 881018,during Insp Ice Condenser Basket Found W/Bottom Screws Missing.Caused by Installation Deficiency Because of Improper Matl Selection.Work Request Initiated to Replace Improper screws.W/900530 Ltr ML20043D7121990-05-30030 May 1990 LER 90-006-00:on 900226,discovered Abnormal Degradation on Steel Containment Vessel.Corrosion Caused by Design Deficiency Caused by Unanticipated Environ Interaction. Detailed Insps conducted.W/900529 Ltr ML20043C8041990-05-30030 May 1990 LER 90-008-00:on 900430,radiation Monitor for Contaminated Parts Warehouse Ventilation & Sampler Min Flow Device Declared Inoperable.Caused by Personnel Error.Appropriate Procedures Enhanced to Prevent recurrence.W/900530 Ltr ML20012D1651990-03-19019 March 1990 LER 90-004-00:on 900208,determined That Holes Left in Auxiliary Shutdown Panel Could Allow Water Spray Into Cabinet.Cause Unknown.Holes Covered W/Duct Tape & Repaired. W/900319 Ltr ML20011F4261990-02-16016 February 1990 LER 90-002-00:on 900117,hold Down Screws on Sylvania Contactors in Motor Control Ctrs Found Loose.Caused by Mfg Deficiency.Contactor Screws Tightened.All Hold Down Screws Will Be Replaced W/Another type.W/900223 Ltr ML20006D5571990-02-0707 February 1990 LER 90-001-00:on 900108,reactor Trip Occurred Due to Clogged Strainer on Feedwater Pump a Speed Controller.Caused by Water in Oil Sys.Cause for Water Presence in Sys Unknown. Sludge Minimization Attempts pursued.W/900207 Ltr ML20006A8771990-01-21021 January 1990 LER 89-028-00:on 891204,self-initiated Technical Audit Team Personnel Identified Gap Around Control Room Ventilation Air Handling Unit Access Door.Caused by Possible Const/ Installation Deficiency.Door Sys modified.W/900122 Ltr ML19327C2581989-11-13013 November 1989 LER 89-031-00:on 891012,ac Power Supply Fuse Blew Resulting in Automatic Isolation of Four Outside Air Intakes on Ventilation Sys.Caused by Inappropriate Action.Intake Valves Returned to Svc & Tech Spec 3.3.3.1 exited.W/891113 Ltr ML19324C2031989-11-10010 November 1989 LER 89-024-00:on 890908,MSIV Stroke Timing Periodic Test Performed W/O Air Assistance & Three MSIVs Failed to Close within 5 S.Caused by Brass Guide Screws Excessively Tightened.Set Screws Properly set.W/891106 Ltr ML19324C2011989-10-31031 October 1989 LER 88-019-02:on 880719,damper Compartment Flows Did Not Meet Flow Requirements Due to Closure of Some Sys Dampers. Caused by Defective procedure.As-found Measurements Taken While Operating Fans for Damper positions.W/891030 Ltr ML19327B5611989-10-26026 October 1989 LER 89-030-00:on 890714,visual Insp Revealed 3/4 Inch Open Conduit Connection Which Would Have Prevented Successful Leak Test.Cause Unknown.Connection Removed & Hole Sealed. W/891026 Ltr ML19327B4771989-10-23023 October 1989 LER 89-029-00:on 890922,ESF Actuation Occurred When Diesel Generator 1A Started Due to Momentary Undervoltage Condition on Train a 4,160-volt Essential Switchgear.Cause Unknown. Offsite Power Source Returned to Normal svc.W/891023 Ltr ML19327B1511989-10-19019 October 1989 LER 89-026-00:on 890720,both Trains of Control Area Ventilation Sys Inoperable.Caused by Design Deficiency Because of Unanticipated Interaction of Components.Original Check Damper Reinstalled in Fan on Train B.W/891019 Ltr ML19351A4301989-10-18018 October 1989 LER 89-025-00:on 890918,jumper Came Loose & Inadvertently Made Contact W/Sliding Link B-14 Directly Above Link B-15, Resulting in Turbine Driven Feedwater Pump Automatically Starting.Caused by Inappropriate action.W/891018 Ltr ML19325D4991989-10-16016 October 1989 LER 89-027-00:on 890915,preheaters Did Not Start Because Air Flow Permissive Was Not Made & Cross Connect Dampers Were Closed & Tagged & Ventilation Sys Train a Remained Logged Inoperable.Caused by Design deficiency.W/891016 Ltr ML19325C4871989-09-28028 September 1989 LER 89-018-00:on 890829,both Trains of Control Area Ventilation (VC) & Chilled Water (Yc) Sys Declared Inoperable.Caused by Equipment/Failure Malfunction. Refrigerant Added to Vc/Yc chiller.W/890928 Ltr ML20043D7041989-09-25025 September 1989 LER 89-022-01:on 890826,reactor Trip Occurred Due to Failed Universal Board in Solid State Protection Sys Cabinet A. Caused by Equipment/Malfunction.Universal Board Replaced. W/900530 Ltr ML19325C4731989-09-18018 September 1989 LER 89-015-00:on 890722,discovered That Neutral Pressure Was Best That Could Be Achieved in Some Required Sys Configurations.Caused by Design Deficiency Due to Design Oversight.Outside Air Ref Point installed.W/891004 Ltr ML20024F2791983-08-29029 August 1983 LER 83-066/03L-0:on 830817,invalid Alarm Received for Fire Detection Zone Efa 90 Which Would Not Clear.Caused by Unusual Svc Conditions.Detector Cleaned & replaced.W/830829 Ltr ML20024D8101983-07-29029 July 1983 LER 83-050/03L-0:on 830629,control Area Ventilation Sys Train B Declared Inoperable.Caused by Automatic Reset Preheater Overtemp Cutout Switch Failure.Replacement Switch Will Be installed.W/830729 Ltr ML20024D7531983-07-27027 July 1983 LER 83-048/03L-0:on 830624,control Area Ventilation Sys Train B Declared Inoperable Following Low Refrigerant Temp Alarm Trip of Control Room Chiller B.Caused by Cleaning of Condenser tubes.W/830727 Ltr ML20024D7701983-07-27027 July 1983 LER 83-049/03L-0:on 830624,surveillance Compliance Review Revealed Three Time Response Tests Not Performed.Cause Not Stated.Remaining Channels Will Be Tested During Next refueling.W/830727 Ltr ML20024D8951983-07-27027 July 1983 LER 83-047/03L-0:on 830627,discovered That 18-month Insp of Fire Hose Station 180 Not Performed During Nov 1981.Caused by Order Preventing Personnel from Entering Area Due to High Radiation Levels.Procedural Change instituted.W/830727 Ltr ML20024C4091983-06-28028 June 1983 Updated LER 83-002/03X-1:on 830110,pressurizer Heater Group 1B Failed to Energize in Manual & Declared Inoperable.Heat Damage Found at Heat Dissipating Resistor Connections.Caused by Design Defect in Contactor Coil circuit.W/830628 Ltr ML20024C3941983-06-28028 June 1983 LER 83-035/03L-0:on 830515,pressurizer Heater Group 1B Failed to Energize in Manual & Declared Inoperable Per Tech Spec 3.4.3.Caused by Blown Fuse in Heater Contactor Control Circuit.Fuse replaced.W/830628 Ltr ML20024C0001983-06-27027 June 1983 LER 83-030/01T-0:on 830526,discovered Monthly Test of Containment Pressure Control Sys Failed to Satisfy Surveillance Requirements to Check Permissive/Termination Setpoint Accuracy.Alarm Modules recalibr.W/830627 Ltr ML20023C4691983-05-0505 May 1983 LER 83-017/03L-0:on 830405,during Draining of Refueling Cavity RHR (Nd) Pumps Began to Cavitate & Eventually Both Nd Pumps Stopped.Caused by Level Gauge Isolation.Cavity Refilled.Nd Sys Vented.Procedures Revised ML20028E0131983-01-10010 January 1983 LER 82-081/03L-0:on 821211,lower Personnel Airlock Declared Inoperable After Reactor Door Found Partially Closed W/Small Seal Ruptured & Large Seal Inflated.Cause Not Known.Seal Not Designed to Withstand Unrestrained Inflationary Forces ML20028A5301982-11-10010 November 1982 LER 82-073/03L-0:on 820403,during QA Audit of Test Procedures,Incore & Nuclear Instrumentation Sys Correlation Monthly Check Found Not Performed.Caused by Incorrect Test Schedule ML20027D3351982-10-22022 October 1982 LER 82-071/03L-0:on 820922,motor Control Ctr Lemxd Lost Power Causing Temporary Inoperability of Several Essential Sys/Components.Caused by Automatic Trip of Feeder Breaker. Breaker Reset & Closed.Power Restored ML20027B5051982-09-10010 September 1982 LER 82-067/03L-0:on 820813,two Auxiliary Feedwater Pump Turbine Low Suction Pressure Switches Failed to Perform During Functional Test.Caused by Switches Being Out of Calibr,Possibly Due to Instrument Drift or Misadjustment ML20027B5521982-09-0808 September 1982 LER 82-064/03L-0:on 820809,vent Flow Monitor Indicated Zero W/Vent in Operation During Process of Returning to Mode 1. Caused by Out of Calibr Differential Pressure Transmitter Due to Instrument Drift.Transmitter Recalibr ML20052H5831982-05-10010 May 1982 LER 82-027/03L-0:on 820326,one Channel of Position Indication for RCS Power Operated Relief Valves NC-32 & NC-36 Declared Inoperable When Closed Indicator Lights Failed.Caused by Loose Fitting Bulb Due to Crack in Socket ML20052G6791982-05-0707 May 1982 LER 82-030/01T-0:on 820423,diesel Generator 1A Declared Inoperable After Failing to Start for Periodic Test.Caused by Failure of Station Design Change Implementation Program to Control Work on Station Mods ML20052H7421982-05-0707 May 1982 LER 82-031/03L-0:on 820408,boric Acid Transfer Pump a Failed to Perform at Capacity & Declared Inoperable.Caused by Reverse Rotation Due to Improperly Connected Windings. Personnel Counseled & Maint Routine Modified ML20052H7481982-05-0606 May 1982 LER 82-029/03L-0:on 820402,investigation of Power Operated Relief Valve (PORV) & Pressurizer Code Safety Discharge Line High Temp Alarms Revealed Indications of Leakage for PORV NC-34.Cause Undetermined.Valve Will Be Repaired ML20052H6091982-04-30030 April 1982 LER 82-028/03L-0:on 820401,during Mode 1 Operation,Radiation Monitors EMF-31 & EMF-33 Lost Power.Caused by Monitor EMF-46 Tripping Circuit Breaker Due to Direct Short Across Power bulb.EMF-46 Isolated & EMF-31 & 33 Returned to Svc ML20052G3611982-04-29029 April 1982 LER 82-025/03L-0:on 820318,vol Control Tank Makeup Frequency Increased & Containment Floor & Equipment Sump 1A Level Increased During RCS Leak Test.Caused by Failure to Verify Isolation Valves Closed Due to Procedural Deficiency 1994-10-05
[Table view] Category:RO)
MONTHYEARML20024J3211994-10-0505 October 1994 LER 94-006-00:on 940909,failure to Perform Slave Relay Test Associated W/One Containment Isolation Valve Due to Improper Work Practices.Reviewed All Slave Relay Test Procedures & Trained All Qualified reviewers.W/941005 Ltr ML20046B5251993-08-0404 August 1993 LER 93-007-00:on 930705,TS Required Surveillance Was Not Performed Because of Inappropriate Action Because of Lack of Attention to Detail.Generated WO 93047633 to Perform Required Surveillance on Unit 1 IPE CA 9010.W/930729 Ltr ML20045H9821993-07-12012 July 1993 LER 93-005-00:on 930612,manual Rt in Unit 1 Occurred Due to Equipment Failure Due to Failure of L-13 Field Cable Between Data Cabinet B & Bulkhead for Undetermined Reasons.Replaced Field cable.W/930709 Ltr ML20045D9681993-06-25025 June 1993 LER 93-006-00:on 930526,discovered That Sample Blower for Radiation Monitor 1 EMF-43B Off & Monitor Declared Inoperable & Ventilation Sys Air Intakes Not Isolated.Caused by Deficient Procedures.Test Procedures Revised ML20045B2811993-06-11011 June 1993 LER 93-004-00:on 930513,both Trains of CR Ventilation Sys Declared Inoperable Due to Equipment Failure.Exact Cause of Failure Could Not Be Determined.Train B Nuclear Svc Water Sys Flow Balance completed.W/930611 Ltr ML20029C2091991-03-21021 March 1991 LER 91-003-00:on 910219,both Trains of Control Room Ventilation Sys Inoperable.Caused by Design Malfunction & Management Deficiency.Temporary Modifications,Removing Automatic Closure Function implemented.W/910321 Ltr ML20028G9561990-09-26026 September 1990 LER 90-025-00:on 900827,Unit 1 Shut Down Because of Unidentified RCS Leakage Exceeding Tech Spec Limits.Caused by Equipment Failure.Procedure AP/1/A/5500/10 Implemented. Valve 1NC-33 Will Be Repacked at Next outage.W/900926 Ltr ML20044A0091990-06-25025 June 1990 LER 90-015-00:on 900524,Tech Spec 3.0.3 Entered Because More than One Power Range Nuclear Instrumentation Channel Exceeded 5% Deviation.Caused by Mgt Deficiency.Boric Acid Added to Coolant sys.W/900625 Ltr ML20043H4991990-06-21021 June 1990 LER 90-012-00:on 900522,loose Matl,Consisting of Masslin Cloths & Stepoff Pad,Discovered in Upper Containment.Caused by Failure to Follow Procedures.Loose Items Removed & Cleanliness Procedures revised.W/900621 Ltr ML20043H2641990-06-20020 June 1990 LER 90-011-00:on 900521,noted That Valve 1RN-69A Auxiliary Feedwater Assured Supply from Train a Nuclear Svc Water Repositioned to Open Position After Start of Pump.Cause Unknown.Pump Shut Down & Valve closed.W/900620 Ltr ML20043F7471990-06-13013 June 1990 LER 90-010-00:on 900427,discovered That Annulus Ventilation & Control Room Ventilation Sys Headers Would Not Operate,As Designed,Under Postulated Operating Conditions. Caused by Design Deficiency.Change submitted.W/900613 Ltr ML20043F5071990-06-11011 June 1990 LER 90-009-00:on 900512,feedwater Isolation Occurred as Result of Steam Generator 1B Reaching hi-hi Level Setpoint of 82% Level.Caused by Inappropriate Action Because of Lack of Attention to Detail.Feedwater Logic reset.W/900611 Ltr ML20043D6541990-05-30030 May 1990 LER 90-007-00:on 881018,during Insp Ice Condenser Basket Found W/Bottom Screws Missing.Caused by Installation Deficiency Because of Improper Matl Selection.Work Request Initiated to Replace Improper screws.W/900530 Ltr ML20043D7121990-05-30030 May 1990 LER 90-006-00:on 900226,discovered Abnormal Degradation on Steel Containment Vessel.Corrosion Caused by Design Deficiency Caused by Unanticipated Environ Interaction. Detailed Insps conducted.W/900529 Ltr ML20043C8041990-05-30030 May 1990 LER 90-008-00:on 900430,radiation Monitor for Contaminated Parts Warehouse Ventilation & Sampler Min Flow Device Declared Inoperable.Caused by Personnel Error.Appropriate Procedures Enhanced to Prevent recurrence.W/900530 Ltr ML20012D1651990-03-19019 March 1990 LER 90-004-00:on 900208,determined That Holes Left in Auxiliary Shutdown Panel Could Allow Water Spray Into Cabinet.Cause Unknown.Holes Covered W/Duct Tape & Repaired. W/900319 Ltr ML20011F4261990-02-16016 February 1990 LER 90-002-00:on 900117,hold Down Screws on Sylvania Contactors in Motor Control Ctrs Found Loose.Caused by Mfg Deficiency.Contactor Screws Tightened.All Hold Down Screws Will Be Replaced W/Another type.W/900223 Ltr ML20006D5571990-02-0707 February 1990 LER 90-001-00:on 900108,reactor Trip Occurred Due to Clogged Strainer on Feedwater Pump a Speed Controller.Caused by Water in Oil Sys.Cause for Water Presence in Sys Unknown. Sludge Minimization Attempts pursued.W/900207 Ltr ML20006A8771990-01-21021 January 1990 LER 89-028-00:on 891204,self-initiated Technical Audit Team Personnel Identified Gap Around Control Room Ventilation Air Handling Unit Access Door.Caused by Possible Const/ Installation Deficiency.Door Sys modified.W/900122 Ltr ML19327C2581989-11-13013 November 1989 LER 89-031-00:on 891012,ac Power Supply Fuse Blew Resulting in Automatic Isolation of Four Outside Air Intakes on Ventilation Sys.Caused by Inappropriate Action.Intake Valves Returned to Svc & Tech Spec 3.3.3.1 exited.W/891113 Ltr ML19324C2031989-11-10010 November 1989 LER 89-024-00:on 890908,MSIV Stroke Timing Periodic Test Performed W/O Air Assistance & Three MSIVs Failed to Close within 5 S.Caused by Brass Guide Screws Excessively Tightened.Set Screws Properly set.W/891106 Ltr ML19324C2011989-10-31031 October 1989 LER 88-019-02:on 880719,damper Compartment Flows Did Not Meet Flow Requirements Due to Closure of Some Sys Dampers. Caused by Defective procedure.As-found Measurements Taken While Operating Fans for Damper positions.W/891030 Ltr ML19327B5611989-10-26026 October 1989 LER 89-030-00:on 890714,visual Insp Revealed 3/4 Inch Open Conduit Connection Which Would Have Prevented Successful Leak Test.Cause Unknown.Connection Removed & Hole Sealed. W/891026 Ltr ML19327B4771989-10-23023 October 1989 LER 89-029-00:on 890922,ESF Actuation Occurred When Diesel Generator 1A Started Due to Momentary Undervoltage Condition on Train a 4,160-volt Essential Switchgear.Cause Unknown. Offsite Power Source Returned to Normal svc.W/891023 Ltr ML19327B1511989-10-19019 October 1989 LER 89-026-00:on 890720,both Trains of Control Area Ventilation Sys Inoperable.Caused by Design Deficiency Because of Unanticipated Interaction of Components.Original Check Damper Reinstalled in Fan on Train B.W/891019 Ltr ML19351A4301989-10-18018 October 1989 LER 89-025-00:on 890918,jumper Came Loose & Inadvertently Made Contact W/Sliding Link B-14 Directly Above Link B-15, Resulting in Turbine Driven Feedwater Pump Automatically Starting.Caused by Inappropriate action.W/891018 Ltr ML19325D4991989-10-16016 October 1989 LER 89-027-00:on 890915,preheaters Did Not Start Because Air Flow Permissive Was Not Made & Cross Connect Dampers Were Closed & Tagged & Ventilation Sys Train a Remained Logged Inoperable.Caused by Design deficiency.W/891016 Ltr ML19325C4871989-09-28028 September 1989 LER 89-018-00:on 890829,both Trains of Control Area Ventilation (VC) & Chilled Water (Yc) Sys Declared Inoperable.Caused by Equipment/Failure Malfunction. Refrigerant Added to Vc/Yc chiller.W/890928 Ltr ML20043D7041989-09-25025 September 1989 LER 89-022-01:on 890826,reactor Trip Occurred Due to Failed Universal Board in Solid State Protection Sys Cabinet A. Caused by Equipment/Malfunction.Universal Board Replaced. W/900530 Ltr ML19325C4731989-09-18018 September 1989 LER 89-015-00:on 890722,discovered That Neutral Pressure Was Best That Could Be Achieved in Some Required Sys Configurations.Caused by Design Deficiency Due to Design Oversight.Outside Air Ref Point installed.W/891004 Ltr ML20024F2791983-08-29029 August 1983 LER 83-066/03L-0:on 830817,invalid Alarm Received for Fire Detection Zone Efa 90 Which Would Not Clear.Caused by Unusual Svc Conditions.Detector Cleaned & replaced.W/830829 Ltr ML20024D8101983-07-29029 July 1983 LER 83-050/03L-0:on 830629,control Area Ventilation Sys Train B Declared Inoperable.Caused by Automatic Reset Preheater Overtemp Cutout Switch Failure.Replacement Switch Will Be installed.W/830729 Ltr ML20024D7531983-07-27027 July 1983 LER 83-048/03L-0:on 830624,control Area Ventilation Sys Train B Declared Inoperable Following Low Refrigerant Temp Alarm Trip of Control Room Chiller B.Caused by Cleaning of Condenser tubes.W/830727 Ltr ML20024D7701983-07-27027 July 1983 LER 83-049/03L-0:on 830624,surveillance Compliance Review Revealed Three Time Response Tests Not Performed.Cause Not Stated.Remaining Channels Will Be Tested During Next refueling.W/830727 Ltr ML20024D8951983-07-27027 July 1983 LER 83-047/03L-0:on 830627,discovered That 18-month Insp of Fire Hose Station 180 Not Performed During Nov 1981.Caused by Order Preventing Personnel from Entering Area Due to High Radiation Levels.Procedural Change instituted.W/830727 Ltr ML20024C4091983-06-28028 June 1983 Updated LER 83-002/03X-1:on 830110,pressurizer Heater Group 1B Failed to Energize in Manual & Declared Inoperable.Heat Damage Found at Heat Dissipating Resistor Connections.Caused by Design Defect in Contactor Coil circuit.W/830628 Ltr ML20024C3941983-06-28028 June 1983 LER 83-035/03L-0:on 830515,pressurizer Heater Group 1B Failed to Energize in Manual & Declared Inoperable Per Tech Spec 3.4.3.Caused by Blown Fuse in Heater Contactor Control Circuit.Fuse replaced.W/830628 Ltr ML20024C0001983-06-27027 June 1983 LER 83-030/01T-0:on 830526,discovered Monthly Test of Containment Pressure Control Sys Failed to Satisfy Surveillance Requirements to Check Permissive/Termination Setpoint Accuracy.Alarm Modules recalibr.W/830627 Ltr ML20023C4691983-05-0505 May 1983 LER 83-017/03L-0:on 830405,during Draining of Refueling Cavity RHR (Nd) Pumps Began to Cavitate & Eventually Both Nd Pumps Stopped.Caused by Level Gauge Isolation.Cavity Refilled.Nd Sys Vented.Procedures Revised ML20028E0131983-01-10010 January 1983 LER 82-081/03L-0:on 821211,lower Personnel Airlock Declared Inoperable After Reactor Door Found Partially Closed W/Small Seal Ruptured & Large Seal Inflated.Cause Not Known.Seal Not Designed to Withstand Unrestrained Inflationary Forces ML20028A5301982-11-10010 November 1982 LER 82-073/03L-0:on 820403,during QA Audit of Test Procedures,Incore & Nuclear Instrumentation Sys Correlation Monthly Check Found Not Performed.Caused by Incorrect Test Schedule ML20027D3351982-10-22022 October 1982 LER 82-071/03L-0:on 820922,motor Control Ctr Lemxd Lost Power Causing Temporary Inoperability of Several Essential Sys/Components.Caused by Automatic Trip of Feeder Breaker. Breaker Reset & Closed.Power Restored ML20027B5051982-09-10010 September 1982 LER 82-067/03L-0:on 820813,two Auxiliary Feedwater Pump Turbine Low Suction Pressure Switches Failed to Perform During Functional Test.Caused by Switches Being Out of Calibr,Possibly Due to Instrument Drift or Misadjustment ML20027B5521982-09-0808 September 1982 LER 82-064/03L-0:on 820809,vent Flow Monitor Indicated Zero W/Vent in Operation During Process of Returning to Mode 1. Caused by Out of Calibr Differential Pressure Transmitter Due to Instrument Drift.Transmitter Recalibr ML20052H5831982-05-10010 May 1982 LER 82-027/03L-0:on 820326,one Channel of Position Indication for RCS Power Operated Relief Valves NC-32 & NC-36 Declared Inoperable When Closed Indicator Lights Failed.Caused by Loose Fitting Bulb Due to Crack in Socket ML20052G6791982-05-0707 May 1982 LER 82-030/01T-0:on 820423,diesel Generator 1A Declared Inoperable After Failing to Start for Periodic Test.Caused by Failure of Station Design Change Implementation Program to Control Work on Station Mods ML20052H7421982-05-0707 May 1982 LER 82-031/03L-0:on 820408,boric Acid Transfer Pump a Failed to Perform at Capacity & Declared Inoperable.Caused by Reverse Rotation Due to Improperly Connected Windings. Personnel Counseled & Maint Routine Modified ML20052H7481982-05-0606 May 1982 LER 82-029/03L-0:on 820402,investigation of Power Operated Relief Valve (PORV) & Pressurizer Code Safety Discharge Line High Temp Alarms Revealed Indications of Leakage for PORV NC-34.Cause Undetermined.Valve Will Be Repaired ML20052H6091982-04-30030 April 1982 LER 82-028/03L-0:on 820401,during Mode 1 Operation,Radiation Monitors EMF-31 & EMF-33 Lost Power.Caused by Monitor EMF-46 Tripping Circuit Breaker Due to Direct Short Across Power bulb.EMF-46 Isolated & EMF-31 & 33 Returned to Svc ML20052G3611982-04-29029 April 1982 LER 82-025/03L-0:on 820318,vol Control Tank Makeup Frequency Increased & Containment Floor & Equipment Sump 1A Level Increased During RCS Leak Test.Caused by Failure to Verify Isolation Valves Closed Due to Procedural Deficiency 1994-10-05
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217G7951999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for McGuire Nuclear Station,Units 1 & 2 ML20217F3661999-09-22022 September 1999 Rev 18 to McGuire Unit 1 Cycle 14 Colr ML20212D1911999-09-20020 September 1999 SER Accepting Exemption from Certain Requirements of 10CFR50,App A,General Design Criterion 57 Closed System Isolation Valves for McGuire Nuclear Station,Units 1 & 2 ML20216E8851999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for McGuire Nuclear Station,Units 1 & 2 ML20211B1281999-08-31031 August 1999 Dynamic Rod Worth Measurement Using Casmo/Simulate ML20217G8101999-08-31031 August 1999 Revised Monthly Operating Repts for Aug 1999 for McGuire Nuclear Station,Unit 1 & 2 ML20211G5261999-08-24024 August 1999 SER Accepting Approval of Second 10-year Interval Inservice Insp Program Plan Request for Relief 98-004 for Plant,Unit 1 ML20211F3441999-08-17017 August 1999 Updated non-proprietary Page 2-4 of TR DPC-NE-2009 ML20210S2371999-07-31031 July 1999 Monthly Operating Repts for July 1999 for McGuire Nuclear Station,Units 1 & 2 ML20216E8951999-07-31031 July 1999 Revised Monthly Operating Repts for July 1999 for McGuire Nuclear Station,Units 1 & 2 ML20209E4361999-07-0909 July 1999 SER Agreeing with Licensee General Interpretation of TS LCO 3.0.6,but Finds No Technical Basis or Guidance That Snubbers Could Be Treated as Exception to General Interpretation ML20196K6631999-07-0707 July 1999 Safety Evaluation Supporting Licensee 990520 Position Re Inoperable Snubbers ML20209H1631999-06-30030 June 1999 Monthly Operating Repts for June 1999 for McGuire Nuclear Station,Units 1 & 2 ML20210S2491999-06-30030 June 1999 Revised Monthly Operating Rept for June 1999 for McGuire Nuclear Station,Units 1 & 2 ML20209H1731999-05-31031 May 1999 Revised Monthly Operating Rept for May 1999 for McGuire Nuclear Station,Units 1 & 2 ML20206T4771999-05-31031 May 1999 Rev 3 to UFSAR Chapter 15 Sys Transient Analysis Methodology ML20196L1881999-05-31031 May 1999 Non-proprietary Rev 1 to DPC-NE-3004, Mass & Energy Release & Containment Response Methodology ML20195K3691999-05-31031 May 1999 Monthly Operating Repts for May 1999 for McGuire Nuclear Station,Units 1 & 2 ML20206N3511999-05-11011 May 1999 Safety Evaluation Accepting Licensee Response to GL 96-05, Periodic Verification of Design-Basis Capability of Safety- Related Movs ML20195K3761999-04-30030 April 1999 Revised MORs for Apr 1999 for McGuire Nuclear Station,Units 1 & 2 ML20206R0891999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for McGuire Nuclear Station,Units 1 & 2 ML20205L2341999-04-0505 April 1999 SFP Criticality Analysis ML20206R0931999-03-31031 March 1999 Revised Monthly Repts for Mar 1999 for McGuire Nuclear Station,Units 1 & 2 ML20205P8991999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for McGuire Nuclear Station,Units 1 & 2 ML20205C4171999-03-25025 March 1999 Special Rept 99-02:on 801027,Commission Approved for publication,10CFR50.48 & 10CFR50 App R Delineating Certain Fire Protection Provisions for Nuclear Power Plants Licensed to Operate Prior to 790101.Team Draft Findings Reviewed ML20207K2051999-03-0505 March 1999 Special Rept 99-01:on 990128,DG Tripped After 2 H of Operation During Loaded Operation for Monthly Test.Caused by Several Components That Were Degraded or Had Intermittent Problems.Parts Were Replaced & Initial Run Was Performed ML20204C8911999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for McGuire Nuclear Station,Units 1 & 2 ML20205P9021999-02-28028 February 1999 Revised Monthly Operating Repts for Feb 1999 for McGuire Nuclear Station,Units 1 & 2 ML20204C8961999-01-31031 January 1999 Revised Monthly Operating Repts for Jan 1999 for McGuire Nuclear Station,Units 1 & 2 ML20199E0301998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for McGuire Nuclear Station,Units 1 & 2 ML20216F9931998-12-31031 December 1998 Piedmont Municipal Power Agency 1998 Annual Rept ML20198A4481998-12-11011 December 1998 Safety Evaluation Concluding That for Relief Request 97-004, Parts 1 & 2,ASME Code Exam Requirements Are Impractical. Request for Relief & Alternative Imposed,Granted ML20198D7561998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for McGuire Nuclear Station,Units 1 & 2 ML20199E0491998-11-30030 November 1998 Revised Monthly Operating Rept for Nov 1998 for McGuire Nuclear Station,Units 1 & 2 Re Personnel Exposure ML20199E9651998-11-24024 November 1998 Rev 1 to ATI-98-012-T005, DPC Evaluation of McGuire Unit 1 Surveillance Weld Data Credibility ML20196D4171998-11-24024 November 1998 Special Rept 98-02:on 981112,failure to Implement Fire Watches in Rooms Containing Inoperable Fire Barrier Penetrations,Was Determined.Repair of Affected Fire Barriers in Progress ML20196G0581998-11-0606 November 1998 Rev 17 to COLR Cycle 13 for McGuire Unit 1 ML20196G0761998-11-0606 November 1998 Rev 15 to COLR Cycle 12 for McGuire Unit 2 ML20198D7771998-10-31031 October 1998 Revised Monthly Operating Rept for Oct 1998 for McGuire Nuclear Station,Units 1 & 2 ML20195E5961998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for McGuire Nuclear Station,Units 1 & 2 ML20154L6251998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for McGuire Nuclear Station,Units 1 & 2 ML20195E6021998-09-30030 September 1998 Revised Monthly Operating Rept for Sept 1998 for McGuire Nuclear Station,Units 1 & 2 ML20154B4131998-09-22022 September 1998 Rev 0 to ISI Rept for McGuire Nuclear Unit 1 Twelfth Refueling Outage ML20151W3521998-09-0808 September 1998 Special Rept 98-01:on 980819,maint Could Not Be Performed on FPS Due to Isolation Boundary Leakage.Caused by Inadequate Info Provided in Fire Impairment Plan.Isolated Portion of FPS Was Returned to Svc ML20154L6321998-08-31031 August 1998 Rev 1 to MOR for Aug 1998 for McGuire Nuclear Station,Unit 1 ML20153B3741998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for McGuire Nuclear Station,Units 1 & 2 ML20236U1601998-07-31031 July 1998 Non-proprietary DPC-NE-2009, DPC W Fuel Transition Rept ML20237B2381998-07-31031 July 1998 Monthly Operating Repts for July 1998 for McGuire Nuclear Station,Units 1 & 2 ML20153B3931998-07-31031 July 1998 Revised Monthly Operating Repts for Jul 1998 for McGuire Nuclear Station,Units 1 & 2 ML20236P0451998-07-0808 July 1998 Part 21 Rept Re non-conformance & Potential Defect in Component of Nordberg Model FS1316HSC Standby Dg.Caused by Outer Spring Valves Mfg from Matl That Did Not Meet Specifications.Will Furnish Written Rept within 60 Days 1999-09-30
[Table view] |
Text
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.ll l Dide Mrr Company (IO4)STS 4l40
, McGuire Nuclew Statica
.tiut)llagers krry And ils tersttile, NC18018 8985 DUKk POWER September 26, 1990 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555
Subject:
McGuire Nuclear Station Unit 1 Docket No. 50-369 Licensee Event Report 369/90-25 Gentlement Pursuant to 10 Cra 50.73 Sections (a)(1) and (d), attached is Licensee Event Report 369/90-25 concerning a forced shutdown due to an Unidentified Reactor Coolant leak. This report is being submitted in accordance with 10 CFR 50.73(a)(2)(1)(a). This event is conaidered to be of no signif!cance with respect to the health and safety of the public.
Very truly yours, g2' M T.L. McConnell DVE/ADJ/chl Attachment xc t . Mr. S.D. Ebneter .. American Nuclear Insurers Administrator, Region II. c/o Dottie Sherman, ANI Library U.S. Nuclear Regulatory Commission The Exchange, Suit 245 101 Marietta St., NW, Suite 2900 270 Farmington Avenue Atlanta, GA 30323 Farmington, CT 06032 INPO Records Center Mr. Darl Hood Suite 1500 U.S. Nuclear Regulatory Commission 1100 Circle 75 Parkway Office of Nuclear Reactor Regulation Atlanta, GA 30339 Washington, D.C. 20555 M&M Nuclear Consultants Mr. P.K. Van Doorn 1221 Avenue of the Americas NRC Resident Inspector New York, NY 10020 McGuire Nuclear Station P 66 *
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SUPPttestatT AL RtPORT 4 =PtCit0 lies l wCNtos Day vt&R SUSw'85l0N ttS let yee to.emn CK9tCitO Sv0Mr$SION DA tti NO l l l Amt . AC , ,t . .e e en .e.,,, ... e,. e.,, ,.,,, e .. -, u,.-,.. ,. , n e i On September 27, 1990, at 0554 hours0.00641 days <br />0.154 hours <br />9.160053e-4 weeks <br />2.10797e-4 months <br />, Unit 1 began reducing load to comply with the Unidentified Leaka,3e Technical Specification. Leakage calculations j indicated that unidentifit:d leakage was greater than 1 gallon per minute. An i Unusual Event was declared at this time. Unit 1 entered Mode 3 (Hot Standby), at 1013 hours0.0117 days <br />0.281 hours <br />0.00167 weeks <br />3.854465e-4 months <br />. Entries were made into containment and Pressurizer PORV Header Hi Point Vent valve, INC-252, was found to have a packing leak of
-approximately 8 ounces per hour. The packing was adjusted and the leak stopped. In addition, Pressurizer Relief Isolation valve, INC-33, was found to have a packing leak and the valve stem leakoff line was separated from the i drain pii,ing. The leakoff line was replaced and valve INC-33 was backseated to stop its leakage. The packing on valve INC-33 was torqued to its maximum
-allowed value. The power to the associated Pressurizer Power Operated Relief Valve solenoid was deenergized because valve INC-33 is technically inoperable l while backseated. Valve INC-33 will be repacked during the next outage of sufficient duration. This event is assigned a cause of Equipment Failure.
l Unit I was in Mode 1 (Power Operation) at 100 percent power at the time the l leakage was discovered.
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010 12 OF [6 verta . a .ammwmaca -m.awim EVALUATION:
Background
The Reactor Coolant (NC) system [EIIS:AB] transports-heat from the reactor
[EIIS:RCT] to the steam generators [EIIS:SG), where heat is transferred to the Feedwater [EIIS:SJ) and Main Steam systems [EIIS:SB). During all phases of normal operation, NC system pressure is maintained at or near 2235 pounds per square inch gauge (PSIG), while the Pressurizer [EIIS:PZR] liquid level.
is controlled by the charging flow control in the Chemical and Volume Control system [ETIS:CB].
Technical Specification (TS) 3.4.6.2b, in part, states that NC system leakage shall be limited to 1 gallon per minute (gpm) unidentified leakage. With NC system unidentified leakage greater than 1 gpm, reduce the leakage rate to within limits within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or be in at least Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
TS 3.4.4, in part, states that all power operated relief valves (PORVs)
' [EIIS:RV) and their associated block valves [EIIS:ISV) shall be operable in
't Mode 1 (Power Operation), Mode 2 (Startup), and Mode 3 (Hot Standby). With I' one block valve inoperable, the block valve must be restored to operable status, or closed and deenergized, or the associated PORV must be closed and power removed from its associated solenoid [EIIS: SOL) valve.
An Unusual Event is declared when there is an activity that has occurred or is in progress that has the potential to degrade the level of safety in a nuclear plant. Releases of radioactive material requiring offsite response or monitoring are not expected unless further degradation of safety systems occur.
Description of Event On August 26,1990, at 2240 hours0.0259 days <br />0.622 hours <br />0.0037 weeks <br />8.5232e-4 months <br />, Operations (OPS) personnel were performing procedure PT/1/A/4150/01B, Reactor Coolant System Leakage Calculation. This procedure is required to be performed at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> by TS surveillance requirement 4.4.6.2.1d. Unit I was in Mode 1 (Power Operation) at 100 percent power.
The leakage calculation indicated that unidentified leakage was approximately 2.6 gpm. OPS personnel began checking for other indications of an NC system leak. OPS personnel stated that the frequency of makeup of water to ?.he Volume Control Tank [EIIS:TK] did not indicate excessive leakage. The rate of level increase in the Containment Floor and Equipment Sump and toe Ventilation Unit Condensate Drain Tank also did not indicate an NC system leak, Containment particulate activity, as indicated by radiation monitor
[EIIS: HON] 1 EMF-38L, had shown a moderate increase over the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
The Unit 1 OPS Manager was informed of the leakage calculation results. l Station Directive 2.8.2, ?perability Determination, directs the OPS personnel
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to ensure the validity of the leakage calculation by performing a second calculation. The second NC leakage calculation was initiated on the Operator -
Aid Computer (OAC) (EIIS: CPU) and a manual calculation was performed by the ;
Reactor Operators. The results of these calculations also indicated that NC system unidentified leakage was greater than the TS allowable limit. The OPS i Senior Reactor Operator declared the NC system inoperable per TSs at 0024 i hours on August 27, 199C.
OPS personnel implemented procedure AP/1/A/5500/10, NC System Leakage Within The Capacity of Both Charging Pumps. This procedure gives guidance on :
searching for the source of a leak. .
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Attempts to locate the leak were unsuccessful. OPS personnel commenced a load reduction and implemented procedure RP/0/A/5700/01, Notification of Unusual Event, et 0%54 hours on August 27, 1990. Appropriate personnel and regulatory agencies were notified as required by this procedure.
OPS ano Madiation Protection (RP) personnel entered lower containment at 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> in an attempt to find the source of the leak. Valve 11;C-252, 4 Pressurizer PORV Header Hi Point Vent, was found to have a packing leak of approximately 8 ounces per hour. Unit 1 entered Mode 3 at 1013 hours0.0117 days <br />0.281 hours <br />0.00167 weeks <br />3.854465e-4 months <br />. OPS personnel made entries into lower containment at 1120 and again at 1510 in ,
attempts to find the source of the leak. i At 1825 Insulation personnel were cent to the Pressurizer to remove the in',ulation on the pressurizer manway. While in-the Prescurizer area, the Insulators discovered a valve stem leakoff line blowing to atmosphere. The Insulators identified this leak to an OPS person who had entered the -
pressurizer area to assist the Insulators in finding the manway. The valve stem leakoff line was determined to be from valve INC-33, Pressurizer PORV Isolation. The leakoff line had separated at a compression fitting where it was connected with other valve stem leakoff lines which were piped to the NC Drain Tank. Valve INC-33 was backseated (the valve is fully open which by <
design prevents leakage) and the leak stopped. .
Work Request (WR) 42863 nad been issued to adjust the packing on valve 1NC-252 when the leak was discovered. WR 142864 was issued to adjust the packing on valve INC-33 and to replace the valve stem leakoff tubing. Valve INC-252 packing was adjusted satisfactorily. The valve stem leakoff line for valve INC-33 was replaced. Valve INO-33 was left in its backseat position after the packing wa. overtorqued to prevent further leakage. With valve INC-33 backseated, it is inoperable. WR 142869 was written to de-energize the solenoid valve for INC-34, Pressurizer PORV, to comply with TS 3.4.4.
Leakage calculations were satisfactorily performed on August 24, 1990, at 2035 and again at 2348 hours0.0272 days <br />0.652 hours <br />0.00388 weeks <br />8.93414e-4 months <br />. Both of these calculations indicated that NC system leakage war within TS limits. ,
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0 l 0l l4 0F [6 TSrf ta' mese amm6e 4 assing ese caminar MC h Jae w (1h OPS personnel declared the NC system operable and secured from the Unusual Event at 0030 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> on August 28, 1990. Unit Startup was commenced, and the unit entered Mode 1 at 0530 hours0.00613 days <br />0.147 hours <br />8.763227e-4 weeks <br />2.01665e-4 months <br /> on August 28, 1990.
Conclusion This event is assigned a root cause of Equipment Failure. Valve stem leakage through the packing of valve INC-33 is normally piped to the NC Drain Tank.
This leakage is aacounted for as identified leakage in the NC system leakage calculations. The valve stem leakoff line separated at the point where the leakoff line connected to other valve stem leakoffs. This allowed the leakage to go to containment atmosphere. The leakoff line had separated at a compression fitting. The exact cause of the separation could not be determined.
Valve stem leakage through the valve packing occurs through normal usage of the valves. Valve INC-252 was found to have a small leak of approximately 8 ounces per hour. This leakage stopped when the packing was adjusted by Maintenance personnel. Valve INC-33 had valve stem leakage through the packing. This leakage stopped when the valve was backseated. The packing I was torqued to the maximum allowed value of 200 in. Ibs. per procedure
' MP/0/A/7600/54, Borg Warner Gate Valve Pressure Seal Bonnet, Air or Motor operated, Corrective Maintenance. Adequate assurance that the packing would not leak without replacing the packing was not available. 0?S and Maintenance personnel decided to leave valve INC-33 in its ba-kseat pa:Jcion until an outage of sufficient duration occurs. The valve wili be repacked at that time. To comply with TSs, the power supply to the solenoid valve for valve INC-34 was deenergized after verifying the valve was closed.
WR 95120 documents that the packing on valve INC-33 was replaced, ar.d the valve stem leakoff line was reconnected in September, 1987. No problems were noted. WR 75334 documents that the valve and the packing for valve 1NC-252 were installed in March 1990. Again, no problems were noted.
A review of the Operating Experience Program data base for the past twenty four months prior to this event revealed no events involving TS shutdowns because of Equipment Failure. LER 370/90-07 describes a TS required shutdown of Unit 2 caused by a vent valve leaking past'its seat. This event had a different root cause and different circumstances. Therefore, this event is not considered recurring.
The packing leak and subsequent temporary repair to valve INC-33 is Nuclear Plant Reliability Data fystem (NPRDS) reportable. Valve INC-33 is a 3 inch gate valve manufactured by Borg Warner Corporation. The valve stem leakoff line for valve INC-33 aad the packing leak on valve INC-252 are not NPRDS reportable.
There were no personnel injuries, radiation overexposures or uncontrolled releases of radioactive materials to the environment as a result of this event.
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0l 2 l5 0l0 l5 or [6 vart <, . n. sm.w anc e., , ama mm CORRECTIVE ACTIONS:
Immediate: OPS pei;onnel implemented procedure AP/1/A/5500/10, NC System Leakage Within The Capacity Of Both Charging Pumps.
Subsequent: 1) OPS personnel commenced a load reduction to comply with TS 3.4.6.2.
- 2) Maintenanc9 personnel adjusted the packing on valve INC-252 i.: accordance with WR 142863.
- 3) Valve 1NU-33 was backseated by OPS personnel and the packing was tightened by Maintenance personnel in accordance with WR 142864.
- 4) The valve stem leakoff line was replaced by Maintenance personnel on valve INC-33 in accordance with WR 142864.
- 5) Power was removed from the solenoid valve for Pressurizer PORV INC-34 by OPS personnel.
Planned: 1) Valve INC-33 will be repacked at the next outage of sufficient duration.
- 2) An investigation by Maintenanco personnel will be 4 conducted to determine the cause of the packing failure on valve INC-33, and corrective measures taken as required.
SAFETY ANALYSIS:
The NC system leakage was detected by the OAC. TS surveillance requires that a leakage calculation be performed at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. OPS personnel perform this calculation on the OAC to satisfy this requirement. - In the event the OAC is unavailable, the procedure for leakage calculations directs the OPS personnel on performing a manual calculation. Other methods of detecting leakage include monitoring the containment atmosphere gaseous and particulate activisy and monitoring the containment sump inventory. These methods ensure that a leak greater than TS limits does not go unnoticed.
Leakage rates of this small amount are well within the capability of a single Centrifugal Charging pump. A makeup flow rate from one centrifugal charging pump is typically adequate to sustain Pressurizer level at 2250 PSIA for a
= break through a 0.375 inch diameter hole. The leakage through the packing on INC-252 and 1NC-33 was much less.
Should other leaks occur and exceed the makeup capacity of a single charging pump, depressurization of the NC system would cause fluid to flow into the _
loops from the Pressurizer resulting in a pressure and level decrease in the pressurizer. A Reactor Trip occurs when the low Pressurizer pressure trip setpoint is reached. Letdown from the NC system to the Chemical en? Volume Control system would automatically be secured when the Pressurizer level decreased to 17 percent level.
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l6 miin . m== anc a mew nn Should the leakage rate continue to exceed makeep rate, Pressurizer pressure would continue to decrease until a Safety Injection signal was generated.
This would automatically start additional pumps to ensure sufficient flooding ,
of the core to prevent excessive clad temperatures.
Valve INC-33 does not play a mitigating role during an accident scenario.
Operation with this valve backseated, until it is repacked, does not present an unreviewed safety question.
The health and safety of the public were not affected by this incident. ;
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