|
---|
Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER)
MONTHYEARNOC-AE-000304, Special Rept Re Evaluation of Units 1 & 2 Containment Tendon Conditions.Grease Voids Were in Excess of 5% in Two Tendons. Voids of 20% or Less Are Considered Reasonable.Containment Integrity Assured1998-09-24024 September 1998 Special Rept Re Evaluation of Units 1 & 2 Containment Tendon Conditions.Grease Voids Were in Excess of 5% in Two Tendons. Voids of 20% or Less Are Considered Reasonable.Containment Integrity Assured NOC-AE-000250, Special Rept:Discovered That Tendon Filler Grease Voids in Excess of SR Max of 5% of Net Duct Vol Existed.Caused by Shrinkage of Grease & Spaces Existing Between Wires in Tendon Wires.Installed Grease Throughout Tendon Ducts1998-08-12012 August 1998 Special Rept:Discovered That Tendon Filler Grease Voids in Excess of SR Max of 5% of Net Duct Vol Existed.Caused by Shrinkage of Grease & Spaces Existing Between Wires in Tendon Wires.Installed Grease Throughout Tendon Ducts NOC-AE-000222, Special Rept:On 980614,nonvalid Failure of Standby Diesel Generator Occurred.Caused by Inadequate Procedure.Failed Potential Transformer Was replaced,B-train 4.16 Kv ESF Switchgear Was Reenergized & Procedure Was Revised1998-07-0909 July 1998 Special Rept:On 980614,nonvalid Failure of Standby Diesel Generator Occurred.Caused by Inadequate Procedure.Failed Potential Transformer Was replaced,B-train 4.16 Kv ESF Switchgear Was Reenergized & Procedure Was Revised NOC-AE-000143, Special Rept:On 980413,declared Primary Meteorological Tower Instrumentation Inoperable Due to Performance of semi-annual Sys Calibr Required by TS 3.3.3.4.Successfully Calibr & Returned Primary Meterological Tower Instruments to Svc1998-04-29029 April 1998 Special Rept:On 980413,declared Primary Meteorological Tower Instrumentation Inoperable Due to Performance of semi-annual Sys Calibr Required by TS 3.3.3.4.Successfully Calibr & Returned Primary Meterological Tower Instruments to Svc NOC-AE-000119, Special Rept:On 980307 & 10,non-valid Failures of Standby Generator 13 Occurred.Caused by out-of-calibration Reverse Power Relay Inadequate Work Procedures Used to Calibrate Relay.Procedures Revised1998-04-0606 April 1998 Special Rept:On 980307 & 10,non-valid Failures of Standby Generator 13 Occurred.Caused by out-of-calibration Reverse Power Relay Inadequate Work Procedures Used to Calibrate Relay.Procedures Revised NOC-AE-000036, Special Rept:On 971111,valid Failure of Sdg 21 Occurred. Caused by Failed Governor Speed Setting Potentiometer.Sdg 21 Governor Speed Setting Potentiometer Replaced1997-12-11011 December 1997 Special Rept:On 971111,valid Failure of Sdg 21 Occurred. Caused by Failed Governor Speed Setting Potentiometer.Sdg 21 Governor Speed Setting Potentiometer Replaced ST-HL-AE-5738, Special Rept:On 970821,declared Standby DG 21 Inoperable to Allow Repairs.Fuel Rack Sys Set of Rotating Shafts & Lever Arms Connecting Engine Governor to Individual Cylinder Fuel Injection Pumps.Binding Ball Joint Replaced1997-09-0909 September 1997 Special Rept:On 970821,declared Standby DG 21 Inoperable to Allow Repairs.Fuel Rack Sys Set of Rotating Shafts & Lever Arms Connecting Engine Governor to Individual Cylinder Fuel Injection Pumps.Binding Ball Joint Replaced ST-HL-AE-5620, Special Rept:On 970312,declared Standby Diesel Generator 13 Inoperable.Caused by Inoperative Reset Coil on K1 Relay. Reinstalled Original K1 Relay in Standby Diesel Generator 13 & Tested Satisfactorily & Sent Failed K1 Relay to Vendor1997-04-0909 April 1997 Special Rept:On 970312,declared Standby Diesel Generator 13 Inoperable.Caused by Inoperative Reset Coil on K1 Relay. Reinstalled Original K1 Relay in Standby Diesel Generator 13 & Tested Satisfactorily & Sent Failed K1 Relay to Vendor ST-HL-AE-5538, Special Rept on 961204,nonvalid Failure of Sdg 11 Occurred. Caused by Lack of Knowledge of Indications Available to Verify Sdg Output Breaker Completely Rack In.Training Bulletin Was Issued to Operations Personnel1996-12-31031 December 1996 Special Rept on 961204,nonvalid Failure of Sdg 11 Occurred. Caused by Lack of Knowledge of Indications Available to Verify Sdg Output Breaker Completely Rack In.Training Bulletin Was Issued to Operations Personnel ST-HL-AE-5432, Special Rept:On 951204,one of Channels in Upper Rv Collection Region Was Declared Inoperable Due to Loss of Sensor Signal.Repair of Two Channels Will Be Performed During Next Unit 2 Refueling1996-07-22022 July 1996 Special Rept:On 951204,one of Channels in Upper Rv Collection Region Was Declared Inoperable Due to Loss of Sensor Signal.Repair of Two Channels Will Be Performed During Next Unit 2 Refueling ST-HL-AE-5393, Special Rept:On 960130,standby DG 11 Valid Failure Caused by Failed op-amp IC Chip on Preposition Board.Voltage Regulator & Preposition Board Replaced1996-06-0606 June 1996 Special Rept:On 960130,standby DG 11 Valid Failure Caused by Failed op-amp IC Chip on Preposition Board.Voltage Regulator & Preposition Board Replaced ST-HL-AE-5310, Special Rept:On 960130,voltage for Sdg Increased to 4600 Vac Exceeding Expected Emergency Mode Setting of 4160 Vac. Caused by Faulty Instantaneous Preposition Board.Sent Failed Voltage Regulator & Preposition Board Offsite for Analysis1996-02-29029 February 1996 Special Rept:On 960130,voltage for Sdg Increased to 4600 Vac Exceeding Expected Emergency Mode Setting of 4160 Vac. Caused by Faulty Instantaneous Preposition Board.Sent Failed Voltage Regulator & Preposition Board Offsite for Analysis ST-HL-AE-5227, Special Rept:On 951022,completed ISI of Unit 2 Sg.Tube Plugs Visually Inspected for Evidence of Leakage.Welded Plugs Installed at Locations1995-11-0202 November 1995 Special Rept:On 951022,completed ISI of Unit 2 Sg.Tube Plugs Visually Inspected for Evidence of Leakage.Welded Plugs Installed at Locations ST-HL-AE-5182, Special Rept:On 950823,valid Failure of Sdg 12 Occurred Due to Misalignment of Reset Coil Contacts Resulting in Intermittent Failure of K1 relay.K1 Relay in Sdg 12 Replaced1995-09-21021 September 1995 Special Rept:On 950823,valid Failure of Sdg 12 Occurred Due to Misalignment of Reset Coil Contacts Resulting in Intermittent Failure of K1 relay.K1 Relay in Sdg 12 Replaced ST-HL-AE-5064, Special Rept:On 950401,thirty-two SG Tubes Containing Circumferential Indications & 14 SG Tubes Containing Axial Indications Plugged1995-04-13013 April 1995 Special Rept:On 950401,thirty-two SG Tubes Containing Circumferential Indications & 14 SG Tubes Containing Axial Indications Plugged ST-HL-AE-4735, Suppl to 930108 Special Rept Re 8R Cylinder Exhaust Temp Exceeding Max Allowable Operating Exhaust Temp of 980 F, During Performance of Sdg 11 Operability Test on 921209. Original Classification as Valid Failure Changed to No Test1994-03-10010 March 1994 Suppl to 930108 Special Rept Re 8R Cylinder Exhaust Temp Exceeding Max Allowable Operating Exhaust Temp of 980 F, During Performance of Sdg 11 Operability Test on 921209. Original Classification as Valid Failure Changed to No Test ST-HL-AE-4713, Special Rept on:940203,standby Diesel Generator 11 Failed to Obtain Normal Voltage & Frequency.Caused by Relay Contact Failure.Investigation of Event Still Ongoing.Results of Investigation Will Be Documented in Special Rept1994-03-0707 March 1994 Special Rept on:940203,standby Diesel Generator 11 Failed to Obtain Normal Voltage & Frequency.Caused by Relay Contact Failure.Investigation of Event Still Ongoing.Results of Investigation Will Be Documented in Special Rept ST-HL-AE-4699, Special Rept:On 940113,SDG 12 Output Breaker Tripped.Caused by Voltage Regulator (Vr) Failure.Final Test Rept from Vr Vendor Will Be Evaluated to Determine If Addl Actions Required to Increase Reliability of Vr Module1994-02-11011 February 1994 Special Rept:On 940113,SDG 12 Output Breaker Tripped.Caused by Voltage Regulator (Vr) Failure.Final Test Rept from Vr Vendor Will Be Evaluated to Determine If Addl Actions Required to Increase Reliability of Vr Module ST-HL-AE-4604, Special Rept:On 930919,valid Failure of Sdg 11 Occurred Due to Failure of Operational Amplifier on pre-position Board. Troublshooting Conducted,Resulting in Replacement pre-position Board1993-10-25025 October 1993 Special Rept:On 930919,valid Failure of Sdg 11 Occurred Due to Failure of Operational Amplifier on pre-position Board. Troublshooting Conducted,Resulting in Replacement pre-position Board ST-HL-AE-4602, Special Rept:On 931007,insp Resulted in Plugging of fifty- One Tubes Between Four Steam Generators.Reasons for Tube Plugging Summarized as Listed1993-10-15015 October 1993 Special Rept:On 931007,insp Resulted in Plugging of fifty- One Tubes Between Four Steam Generators.Reasons for Tube Plugging Summarized as Listed ST-HL-AE-4576, Special Rept:On 930904,completed ISI of Unit 2 Sg.Tube in SG a Had Imperfection Depth Exceeding TS Limit of 40% of Nominal Tube Wall Thickness Due to Avb Wear.Tube Stabilized & Plugged1993-09-16016 September 1993 Special Rept:On 930904,completed ISI of Unit 2 Sg.Tube in SG a Had Imperfection Depth Exceeding TS Limit of 40% of Nominal Tube Wall Thickness Due to Avb Wear.Tube Stabilized & Plugged ST-HL-AE-4300, Special Rept:On 921209,SDG 11 Was Unloaded & Declared Inoperable Due to High Exhaust Temperature.Insp & Lubrication of Remaining Sdgs in Both Units Has Been Performed to Identify Similar Freedom of Movement Problems1993-01-0808 January 1993 Special Rept:On 921209,SDG 11 Was Unloaded & Declared Inoperable Due to High Exhaust Temperature.Insp & Lubrication of Remaining Sdgs in Both Units Has Been Performed to Identify Similar Freedom of Movement Problems ST-HL-AE-4299, Special Rept:On 921128,Seismic Monitoring Sys Declared Inoperable & Placed in Out of Svc Log When Listed Hardware Problems Identified.Caused by Failure to Properly Manage TS Required Equipment Priorities.Sys Returned to Operability1993-01-0707 January 1993 Special Rept:On 921128,Seismic Monitoring Sys Declared Inoperable & Placed in Out of Svc Log When Listed Hardware Problems Identified.Caused by Failure to Properly Manage TS Required Equipment Priorities.Sys Returned to Operability ST-HL-AE-4270, Special Rept:On 921022,nonvalid Failure of Standby DG 12 Occurred During Standby DG Operability Surveillance Test. Caused by Tripped Generator Breaker Lockout Relay at Local Control Panel.Surveillance Procedures to Be Revised1992-11-20020 November 1992 Special Rept:On 921022,nonvalid Failure of Standby DG 12 Occurred During Standby DG Operability Surveillance Test. Caused by Tripped Generator Breaker Lockout Relay at Local Control Panel.Surveillance Procedures to Be Revised ST-HL-AE-4258, Special Rept:On 921007,SDG Tripped on Turbocharger Thrust Bearing Failure.Caused by Improper Installation of New Eutectic or Degradation of Turbocharger.Turbocharger Replaced.Vendor Manual,Drawings & Procedures Revised1992-11-13013 November 1992 Special Rept:On 921007,SDG Tripped on Turbocharger Thrust Bearing Failure.Caused by Improper Installation of New Eutectic or Degradation of Turbocharger.Turbocharger Replaced.Vendor Manual,Drawings & Procedures Revised ST-HL-AE-4262, Special Rept:On 921014,Standby Diesel Generater 12 Shed Load to 0 Kw Due to Failure of Swing Disk Check Valve in Fuel Supply Line.Damaged Check Valve Replaced & Internals Removed.Remaining Check Valves Inspected1992-11-12012 November 1992 Special Rept:On 921014,Standby Diesel Generater 12 Shed Load to 0 Kw Due to Failure of Swing Disk Check Valve in Fuel Supply Line.Damaged Check Valve Replaced & Internals Removed.Remaining Check Valves Inspected ST-HL-AE-4172, Special Rept:On 920708,SDG 13 Tripped on Low Turbocharger Lube Oil & Inlet Pressure.Caused by Presence of Water in Valve Cover Which Led to Corrosion.Design Changes to Provide Drainage to Valves Will Be Evaluated1992-08-0707 August 1992 Special Rept:On 920708,SDG 13 Tripped on Low Turbocharger Lube Oil & Inlet Pressure.Caused by Presence of Water in Valve Cover Which Led to Corrosion.Design Changes to Provide Drainage to Valves Will Be Evaluated ST-HL-AE-4166, Special Rept:On 920630,CR Annunciator Lamp 22M01 Window F-1, Isolation Valve Cubicle Temp High Alarmed.Caused by Train D Cubicle Temp.Investigation Into Root Cause Ongoing1992-07-29029 July 1992 Special Rept:On 920630,CR Annunciator Lamp 22M01 Window F-1, Isolation Valve Cubicle Temp High Alarmed.Caused by Train D Cubicle Temp.Investigation Into Root Cause Ongoing ST-HL-AE-4165, Suppl to 920430 Special Rept:On 920408,nonvalid Failure of Sdg 21 Occurred When Sdg Tripped When Released from Emergency Mode.Cause Not Determined.Power Supply Mfg by Beta Products.No Corrective Actions Warranted1992-07-29029 July 1992 Suppl to 920430 Special Rept:On 920408,nonvalid Failure of Sdg 21 Occurred When Sdg Tripped When Released from Emergency Mode.Cause Not Determined.Power Supply Mfg by Beta Products.No Corrective Actions Warranted ST-HL-AE-4142, Special Rept:On 920610,SDG 22 Tripped When Released from Emergency Mode.Caused by Regulator Valve Not Providing Sufficient Air Pressure.Troubleshooting & Repair on Annunciator Alarm Panel Performed1992-07-0909 July 1992 Special Rept:On 920610,SDG 22 Tripped When Released from Emergency Mode.Caused by Regulator Valve Not Providing Sufficient Air Pressure.Troubleshooting & Repair on Annunciator Alarm Panel Performed ST-HL-AE-4137, Supplement to Special Rept Re Sdg Valid Failure on 901126. Caused by Less than Adequate Design of Delivery Valve Holder Which Is Prone to cracking.Cooper-Bessemer Owners Group Recommendations for Resolving Problem to Be Implemented1992-07-0606 July 1992 Supplement to Special Rept Re Sdg Valid Failure on 901126. Caused by Less than Adequate Design of Delivery Valve Holder Which Is Prone to cracking.Cooper-Bessemer Owners Group Recommendations for Resolving Problem to Be Implemented ST-HL-AE-4094, Special Rept:On 920408,SDG 21 Tripped When Released from Emergency Mode.Cause Has Not Been Determined.Further Analysis & Investigation Performed on Sdg 21.Supplemental Rept Will Be Submitted by 9207301992-05-0808 May 1992 Special Rept:On 920408,SDG 21 Tripped When Released from Emergency Mode.Cause Has Not Been Determined.Further Analysis & Investigation Performed on Sdg 21.Supplemental Rept Will Be Submitted by 920730 ST-HL-AE-4087, Special Rept:On 920409,channels a & C of Reactor Vessel Water Level Indication Sys (Rvwlis) Inoperable.Caused by Type of Copper Wiring Used in Circuit.Rvwlis Probes for Channels a & C Replaced1992-05-0808 May 1992 Special Rept:On 920409,channels a & C of Reactor Vessel Water Level Indication Sys (Rvwlis) Inoperable.Caused by Type of Copper Wiring Used in Circuit.Rvwlis Probes for Channels a & C Replaced ST-HL-AE-4065, Special Rept:On 911206,emergency Mode Sdg 23 Tripped W/No Test Mode Trips Indicated.Caused by Foreign Matl Under Seat of Check Valves Allowing Decrease in Air Pressure. Troubleshooting for Sdg 23 & 24 Has Been Completed1992-04-30030 April 1992 Special Rept:On 911206,emergency Mode Sdg 23 Tripped W/No Test Mode Trips Indicated.Caused by Foreign Matl Under Seat of Check Valves Allowing Decrease in Air Pressure. Troubleshooting for Sdg 23 & 24 Has Been Completed ST-HL-AE-4064, Special Rept:Discovered That Tendon Filler Grease Voids Exceeded Surveillance Requirement 4.6.1.6.1.d.2 Max of 5% Net Duct Vol.Caused by Spaces in Tendon Bubble.Adequate Grease Protection Exists for Tendons1992-04-22022 April 1992 Special Rept:Discovered That Tendon Filler Grease Voids Exceeded Surveillance Requirement 4.6.1.6.1.d.2 Max of 5% Net Duct Vol.Caused by Spaces in Tendon Bubble.Adequate Grease Protection Exists for Tendons ST-HL-AE-4037, Special Rept Re Evaluation of Unit 2 Third Yr Containment Tendon Surveillance.Refilling of Grease Accomplished Simultaneously W/Discoveries of Voids as Result of Insp Process Used1992-03-30030 March 1992 Special Rept Re Evaluation of Unit 2 Third Yr Containment Tendon Surveillance.Refilling of Grease Accomplished Simultaneously W/Discoveries of Voids as Result of Insp Process Used ST-HL-AE-3985, Special Rept:On 911224,control Valve Failed Open Causing Reduction of Reactor Coolant Sys Pressure.Cause Can Not Be Determined.Verified No Loose Connections,High Resistant Contacts or Voltage Fluctuations Present1992-01-23023 January 1992 Special Rept:On 911224,control Valve Failed Open Causing Reduction of Reactor Coolant Sys Pressure.Cause Can Not Be Determined.Verified No Loose Connections,High Resistant Contacts or Voltage Fluctuations Present ST-HL-AE-3960, Special Rept:On 911212,standby Diesel Generator 11 Nonvalid Failure Occurred Due to High Resistance of Relay Contacts within Instantaneous Preposition Board.Instantaneos Preposition Board Replaced & Similar Relays to Be Inspected1992-01-10010 January 1992 Special Rept:On 911212,standby Diesel Generator 11 Nonvalid Failure Occurred Due to High Resistance of Relay Contacts within Instantaneous Preposition Board.Instantaneos Preposition Board Replaced & Similar Relays to Be Inspected ST-HL-AE-3955, Special Rept:On 911206 & 07,standby DGs 23 & 21 Tripped W/ No Test Mode Trips Indicated When Released from Emergency Mode.Cause Not Known.Work Packages Developed to Troubleshoot Standby DGs & to Determine Causes of Trips1992-01-0303 January 1992 Special Rept:On 911206 & 07,standby DGs 23 & 21 Tripped W/ No Test Mode Trips Indicated When Released from Emergency Mode.Cause Not Known.Work Packages Developed to Troubleshoot Standby DGs & to Determine Causes of Trips ST-HL-AE-3929, Supplement to Special Rept:On 910710,spraying Lube Oil Leak Discovered at Cylinder 7R & Engine Manually Secured.Caused by Break in Exhaust rocker-to-inlet Rocker Crossover Lube Oil Line.Design of Lube Oil Line Changed1991-12-19019 December 1991 Supplement to Special Rept:On 910710,spraying Lube Oil Leak Discovered at Cylinder 7R & Engine Manually Secured.Caused by Break in Exhaust rocker-to-inlet Rocker Crossover Lube Oil Line.Design of Lube Oil Line Changed ST-HL-AE-3951, Special Rept:On 911025,SDG 21 Found to Have Fuel Oil Leak at Injection Pump.Caused by Delivery Valve Holder Design Prone to Cracking.Testing Frequency for Sdg 21 Remains at Once Per 31 Days1991-12-18018 December 1991 Special Rept:On 911025,SDG 21 Found to Have Fuel Oil Leak at Injection Pump.Caused by Delivery Valve Holder Design Prone to Cracking.Testing Frequency for Sdg 21 Remains at Once Per 31 Days ST-HL-AE-3937, Special Rept:On 911030,fuel Oil Leak Occurred at Cylinder 5R on High Pressure Fuel Oil Supply Line Connection to Fuel Oil Injector.Evaluation Underway to Determine Cause. Injector & Fuel Oil Line Replaced1991-11-27027 November 1991 Special Rept:On 911030,fuel Oil Leak Occurred at Cylinder 5R on High Pressure Fuel Oil Supply Line Connection to Fuel Oil Injector.Evaluation Underway to Determine Cause. Injector & Fuel Oil Line Replaced ST-HL-AE-3928, Special Rept:On 911025,fuel Oil Leak Found at Injection Pump 9L of Standby Diesel Generator 21.Caused by Crack on Threaded Portion of Delivery Valve Holder.Holder Will Be Replaced W/New Cooper-Bessemer Holder by Next Outage1991-11-25025 November 1991 Special Rept:On 911025,fuel Oil Leak Found at Injection Pump 9L of Standby Diesel Generator 21.Caused by Crack on Threaded Portion of Delivery Valve Holder.Holder Will Be Replaced W/New Cooper-Bessemer Holder by Next Outage ST-HL-AE-3910, Special Rept:On 911006,standby Diesel Generator 21 Tripped & Coasted to Stop.Caused by Malfunction in Amerace Relays in 62CL Circuit Due to End Life.Relays Replaced1991-11-0505 November 1991 Special Rept:On 911006,standby Diesel Generator 21 Tripped & Coasted to Stop.Caused by Malfunction in Amerace Relays in 62CL Circuit Due to End Life.Relays Replaced ML20085D7161991-10-11011 October 1991 Special Rept:On 910913,standby Diesel Generator 23 Would Not Close on Demand from Control Room.Caused by Failure to Fully Rack in Diesel Output Breaker & Inadequate Work Practices. Nonlicensed Operator Counseled & New Policy Will Be Written ST-HL-AE-3889, Special Rept:On 910904,SDG 22 Failed.Caused by Intermittent Malfunctioning of Instantaneous Preposition Board. Instantaneous Preposition Board Replaced & Applicable Relays in Emergency Mode Tested for Proper Resistance1991-10-0404 October 1991 Special Rept:On 910904,SDG 22 Failed.Caused by Intermittent Malfunctioning of Instantaneous Preposition Board. Instantaneous Preposition Board Replaced & Applicable Relays in Emergency Mode Tested for Proper Resistance ST-HL-AE-3900, Special Rept:On 910913,output Breaker CS06 for Standby DG 23 Would Not Close on Demand from Control Room.Nonlicensed Operator Dispatched to Investigate Cause of Event.Caused by Inadequate Work Practices.Personnel Counseled1991-09-13013 September 1991 Special Rept:On 910913,output Breaker CS06 for Standby DG 23 Would Not Close on Demand from Control Room.Nonlicensed Operator Dispatched to Investigate Cause of Event.Caused by Inadequate Work Practices.Personnel Counseled ST-HL-AE-3834, Special Rept:On 910710,spraying Lube Oil Leak Identified at Cylinder 7R & Standby Diesel Generator Declared Inoperable. Caused by Break in Exhaust Rocker to Inlet Rocker Crossover Lube Oil Line.Wall Thickness Tubing Replaced1991-08-0909 August 1991 Special Rept:On 910710,spraying Lube Oil Leak Identified at Cylinder 7R & Standby Diesel Generator Declared Inoperable. Caused by Break in Exhaust Rocker to Inlet Rocker Crossover Lube Oil Line.Wall Thickness Tubing Replaced ST-HL-AE-3837, Suppl to Special Rept Re Inoperable Primary Meteorological Tower Instrument.Primary Meteorological Tower Restored to Operable Status on 910627 & Operator Log Procedures for Towers Enhanced1991-07-31031 July 1991 Suppl to Special Rept Re Inoperable Primary Meteorological Tower Instrument.Primary Meteorological Tower Restored to Operable Status on 910627 & Operator Log Procedures for Towers Enhanced ST-HL-AE-3814, Special Rept:On 910616,primary Meteorological Tower Wind Direction Sensor at 60 Meter Elevation Declared Inoperable Due to Indication Problems Resulting in Entry Into Tech Spec 3.3.3.4 Action Statement1991-07-0303 July 1991 Special Rept:On 910616,primary Meteorological Tower Wind Direction Sensor at 60 Meter Elevation Declared Inoperable Due to Indication Problems Resulting in Entry Into Tech Spec 3.3.3.4 Action Statement 1998-09-24
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217K9441999-10-15015 October 1999 SER Accepting Util Alternative Proposed Relief Request RR-ENG-2-4 for Second 10-year ISI Interval at Stp,Units 1 & 2 Pursuant to 10CFR50.55a(a)(3)(i) ML20217K9151999-10-15015 October 1999 SER Authorizing Util Relief Request RR-ENG-2-3 for Second 10-year ISI Interval of Stp,Units 1 & 2 Pursuant to 10CFR50.55a(a)(3)(i) NOC-AE-000676, Monthly Operating Repts for Sept 1999 for South Texas Project,Units 1 & 2.With1999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for South Texas Project,Units 1 & 2.With ML20217D0531999-09-30030 September 1999 Rev 1 to STP Electric Generating Station Unit 2 Cycle 7 Colr ML20217D0481999-09-30030 September 1999 Rev 1 to STP Electric Generating Station Unit 1 Cycle 9 Colr ML20211P8411999-09-0909 September 1999 Safety Evaluation Supporting Alternative Proposed by Licensee to Surface Exam to Perform Boroscopic VT-1 Visual Exam of Pump Casing Welds within Pump Pits for Welds Covered by Relief Request RR-ENG-24 ML20211P7811999-09-0909 September 1999 SER Approving Second 10-year Interval Inservice Insp Program Plan Relief Request RR-ENG-2-8 (to Use Code Case N-491-2) for South Texas Project,Units 1 & 2 ML20211Q6731999-09-0909 September 1999 Safety Evaluation Accepting First 10-yr Interval ISI Program Plan Request for Relief from ASME Code Case N-498 NOC-AE-000643, Monthly Operating Repts for Aug 1999 for South Texas Project,Units 1 & 2.With1999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for South Texas Project,Units 1 & 2.With ML20212E5191999-08-31031 August 1999 Rev 3 to SG-99-04-005, STP 1RE08 Outage Condition Monitoring Rept & Final Operational Assessment ML20211F4531999-08-24024 August 1999 Safety Evaluation Supporting Licensee Proposed Alternative to Defer Partial First Period Exams of flange-to-shell Weld to Third Period & Perform Required Ultrasonic Exams,Both Manual & Automated,During Third Period ML20211F5111999-08-23023 August 1999 Safety Evaluation Supporting Licensee Proposed Alternative Contained in Request for Relief RR-ENG-30 ML20210C9411999-07-31031 July 1999 Rev 1 to SG-99-07-002, South Tx,Unit 1 Cycle 9 Voltage- Based Repair Criteria 90-Day Rept, Jul 1999 ML20210R3631999-07-31031 July 1999 Monthly Operating Repts for July 1999 for South Tx Project, Units 1 & 2.With ML20210D9161999-07-23023 July 1999 Safety Evaluation Accepting Inservice Testing Relief Request RR-56 Re Component Cooling Water & Safety Injection Sys Containment Isolation Check Valve Closure Test Frequency ML20210D4821999-07-21021 July 1999 1RE08 ISI Summary Rept for Steam Generator Tubing of South Texas Project Electric Generating Station Unit 1 ML20210D4491999-07-21021 July 1999 Revised Chapters to Operations QA Plan, Including Rev 9 to Chapter 1.0, Organization & Rev 6 to Chapter 16.0, Independent Technical Review NOC-AE-000583, LER 99-S03-00:on 990619,failure to Revitalize Sdg Number 11 Was Noted.Caused by Failure to Communicate Status of Sdg. Subject Sdg Revitalized on 990619 & Licensee Will Develop Security Force Instruction Re Sdgs.With1999-07-15015 July 1999 LER 99-S03-00:on 990619,failure to Revitalize Sdg Number 11 Was Noted.Caused by Failure to Communicate Status of Sdg. Subject Sdg Revitalized on 990619 & Licensee Will Develop Security Force Instruction Re Sdgs.With ML20207H6361999-07-0808 July 1999 Safety Evaluation Approving 2nd 10 Yr Interval ISI Program Plan Request to Use ASME Section XI Code Case N-546 for Licenses NPF-76 & NPF-80,respectively ML20216D7481999-07-0707 July 1999 1RE08 ISI Summary Rept for Welds & Component Supports of STP Electric Generating Station,Unit 1 NOC-AE-000593, Monthly Operating Repts for June 1999 for Stp,Units 1 & 2. with1999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Stp,Units 1 & 2. with NOC-AE-000570, LER 99-S01-00:on 990527,discovered That Unescorted Access Had Been Inappropriately Granted.Caused by Failure to Follow Procedure.Util Verified That Individual Did Not Have Current Unescorted Access at STP or Any Other Util.With1999-06-28028 June 1999 LER 99-S01-00:on 990527,discovered That Unescorted Access Had Been Inappropriately Granted.Caused by Failure to Follow Procedure.Util Verified That Individual Did Not Have Current Unescorted Access at STP or Any Other Util.With ML20196G5821999-06-23023 June 1999 LER 99-S02-00:on 990601,failure to Maintain Positive Control of Vital Area Security Key Was Noted.Caused by Lack of Attention to Detail.Discussed Event with Operator Involved IAW Constructive Discipline Program ML20195J6871999-06-17017 June 1999 Safety Evaluation Supporting Proposed Alternative Contained in RR-ENG-2-5.Proposed Alternative Authorized Per 10CFR50.55a(a)(3)(i) for 2nd ISI Interval ML20196A2391999-06-15015 June 1999 Change QA-042 to Rev 13 of Operations QAP, Reflecting Current Organizational Alignment for South Texas Project & Culminating Organizational Realigment That Has Been Taking Place During Past Several Months NOC-AE-000563, Monthly Operating Repts for May 1999 for Stp,Units 1 & 2. with1999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Stp,Units 1 & 2. with ML20206U5411999-05-18018 May 1999 Non-proprietary Errata Pages for Rev 2,Addendum 1 to WCAP-13699, Laser Welded Sleeves for 3/4 Inch Diamete Tube Feedring Type & W Preheater SGs Generic Sleeving Rept ML20206A7721999-04-30030 April 1999 STP Electric Generating Station Unit 1 Cycle 9 Colr NOC-AE-000543, Monthly Operating Repts for Apr 1999 for Stp,Units 1 & 2. with1999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Stp,Units 1 & 2. with ML20205H0321999-03-31031 March 1999 Change QA-040 to Rev 13 of Operations QA Plan NOC-AE-000507, Monthly Operating Repts for Mar 1999 for Stp,Units 1 & 2. with1999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Stp,Units 1 & 2. with ML20205A3781999-03-22022 March 1999 STP Electric Generating Station Simulator Certification Four Yr Rept for Units 1 & 2 ML20204B2711999-03-15015 March 1999 Safety Evaluation Authorizing 990201 Request to Authorize Alternative to Regulations Per 10CFR50.55a(a)(3)(i) That Would Revise Start of Second 120-month IST Interval to No Later than 011201 ML20207M9231999-03-12012 March 1999 Amended Part 21 Rept Re Cooper-Bessemer Ksv EDG Power Piston Failure.Total of 198 or More Pistons Have Been Measured at Seven Different Sites.All Potentially Defective Pistons Have Been Removed from Svc Based on Encl Results NOC-AE-000468, Monthly Operating Repts for Feb 1999 for South Texas Project Electric Generating Station.With1999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for South Texas Project Electric Generating Station.With ML20207D1101999-02-24024 February 1999 Change QA-039 to Rev 13 of Operations QA Plan, for STP ML20203H8361999-02-17017 February 1999 Safety Evaluation Supporting Request for Relief from ASME Code Requirements for Class 3 Piping for Plant ML20202H9621999-02-0303 February 1999 SER Accepting Change to EALs Used in Classification of Emergency Conditions ML20202E8471999-01-31031 January 1999 2RE06 ISI Summary Rept for SG Tubing of STP Electric Generating Station,Unit 2 ML20216G2011999-01-31031 January 1999 City Public Svc of San Antonio Annual Rept 1998-1999 ML20199G5961999-01-31031 January 1999 Cycle 7 Voltage-Based Repair Criteria Rept for Jan 1999 ML20199K7711999-01-21021 January 1999 Safety Evaluation Accepting ISI Program Request for Relief for ASME Cose Repair Requirements for Code Class 3 Piping ML20199G8161999-01-19019 January 1999 SER Accepting Util 970707 Response to NRC 970509 RAI Re GL 92-08, Thermo-Lag 330-1 Fire Barriers. NRC Finds No Significant Safety Hazards Based on Application of Util Ampacity Derating Methodology ML20199H4981999-01-11011 January 1999 2RE06 ISI Summary Rept for Welds & Component Supports of Stp,Unit 2 ML20206Q3751999-01-0404 January 1999 2RE06 ISI Summary Rept for Sys Pressure Tests (Class 1 & 2) ML20206Q3721999-01-0404 January 1999 2RE06 ISI Summary Rept for Repairs & Replacements ML20216G2171998-12-31031 December 1998 Houston Industries 1998 Annual Rept. App a 1998 Financial Statements & Us Securities & Exchange Commission Form 10-K Encl NOC-AE-000403, Monthly Operating Repts for Dec 1998 for South Texas Project Unit 1 & 2.With1998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for South Texas Project Unit 1 & 2.With ML20216G1521998-12-31031 December 1998 Central & South West Corp 1998 Summary Annual Rept & Securities & Exchange Commission Form 10-K ML20198M3431998-12-28028 December 1998 SER Accepting Util Request for Relief from ASME Code Repair Requirements for ASME Code Class 3 Piping for South Texas Project,Unit 2 1999-09-09
[Table view] |
Text
- . -- -_ - .
1 The Light companyS flouston Lighting & l'ower.. _?f3'Tes..projntynagg7nnagng siatign i>, g. nos :89 y.d.worit , Tes.3 774 83 May 8, 1992 ST-IIL-AE-4094 File No.: G02 10CFR$0 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 South Texas Project Unit 2 Docket No. STN 50-499 Special Report Regarding A Non-Valid E011ure of Standby Diesel Gelterator #21 on ADril 8. 1992 P
Pursuant .to . the South Texas Project (STP) Technical Specifications 4.8.1.1.3 and 6.9.2, Houston Lighting & Power (llL&P) submits the attached Special Report regarding Standby Diesel Generator /21 non-valid failure which occurred on April 8, 1992.
If you should have any questions on this matter, please contact Mr. C. A. Ayala at (512) 972-8628 or no at (512) 972-7205.
) bnt. .
William J. Ju Manager, Nuclear Licensing MAC/1f
Attachment:
Special Report Regarding A Non-Valid Failure of SDG #21 on April 8, 1992
-t.200 YO surte2-11s, col I A Subsidiary of Ilouston industries incorporated k 9205'150034 920508 PDR L
'ADOCK 05000499 PDR JT
i 1 1
,' llouston Lighting & Power Company
, Snuth Teras Project Elecith Goiuating Station S fL "4 4 F o1 Pago 2 Col Regional Administrator, Region IV Rufus S. Scott Nuclear Regulatory-Commission Associate General Counsel Gil Ryan Plaza Drive, Sitite 400 Houston Lighting & Power Company .
Arlington, TX 76011 P. O. Box 61867 !
Houston, TX 77208 George Dick, Project Manager U.S. Nuclear Regulatory Commission INPO Washington, DC 20555 Records Conter 1100 Circle 75 Parkway J. I. Tapia Atlanta, GA 30339-3064 Senior Resident Inspector c/o U. S. Nuclear Regulatory Dr. Joseph M. Hendrio Commission 50 Bo11 port Lane _
6 P. O. Box 91P Bellport, NY 11713 Bay City, TX .414 D. X. Lacker J. R. Newman, Esquire Bureau of Radiation Control
- Newman & Holtzinger, P.C. Texas Department of Health 1615 L Street, N.W. 1100 West 49th Street ,
Washington, DC 20036. Austin, TX 78756-3189 '
D.-E. Ward /T. M. Puckett Central Power and Light company P. O. Box 2121 Corpus Christi, TX 78403 J. C. Lanier/M. B. Lee City of-Austin-Electric Utility Department P.O. Box 1088 Austin, TX 78767 X. J. Fiedler/M. T. Hardt City Public Service Board P. O. Box 1771 San Antonio, TX 78296 i
Revised 10/11/91 L4/NRC/
( ,
Attachment ST-HL-AE-4094
,! Page 1 of 2 7
3 South Texas Project O Unit 2 t Docket No. STN 50-499 Special Report Regarding A Non-Valid
'1 4ure of Standby Diesel Generatpr #21 on W il 8. 1992 .
!' Q, 'lON OF EVENT:
\ M, Or- . JL 8, 1992, Unit 2 was in Mode 1 at 100% power. While 3
- - .v Diesel Generator (SDG) #21 Operability Test was being
{
p .c d, the SDG tripped when released from the emergency n. ode. D Fu a; .as or relay fit.gs, which would indicate the cause of the
- g trip w ce detected. In addition, when SDG #21 was started, none p 't the usual starting alarms (i.e., low . starting air pressure, ,
d ycket water standpipe level low) were received.
Troubleshooting or the SOG #21 electrical trig circuitry was >
performed with no problems found. The applicable fuses, relays and timers were verified for proper operation. Various connections '
were inspected which revealed a icose connector to the input side of the annunciator ,ower supply. This connection was repaired. 3 A failed annt u i wrt power supply (PS-2) was also identified. This power sapply vss ed.sequently replaced three times before the cause for thts power supply failures estid be determined. The failure of
( ,
this power supply was criginally thought to have been the cause for the trip - upce release from emergency mode. However, after axtensive troubleshooting, this conclusion could not be supported. j i
A functional check of the engine speed monitor and its associated trip setpoints were verifled. No abnormalities were noted.
.CAUSE OF EVENI:
The cause c' the SDG #21 trip upon release from the emergency mode has not been determined at this time. Previous occurrences of both SDG #21 and #23 trips upon release from the emergency code have been attributed to a loss of air pressure in the pneumatic shutdown header. This event ;s described in the attached correspondence ST-HL-AE-4065 dated April 30, 1992. In addition, undetected electrical faults co.1 .d also result in unannunciated trips upon release from the emergency mooo SREP)02 118,001
-- _ - _ _ _ _ _ _ _ - _ - _ _ _ - _ - _ _ - _ . . _ _ _ . _ _ _ ._ u
- .. . - . . - - . .. - - .- . . ~ . .
4 Attachment ST-HL-AE-4094 Page 2 of 2 ANALYSIS OF EVENT:
This event has been classified as a non valid failure since the SDG
- 21 . operated satisfactorily in the emergency mode and if ciglienged, would have performed its safety function.
CORRECTIVE ACTIONS:
- 1. Further analysis and investigation will be performed on SDG #21.
A supplemental report will be submitted by July 30,. 1992, identifying the cause, if determined, and the- necessary corrective actions.
ADDITIONAL INFORMATIOE:
At the time of the event, there were no valid failures in the last 20 valid tests and loss than 4 valid failures in the last 100 tests for SDG #S?.. Therefoce, the testing frequency will remain at once per 31 c' i s.
. The power supply is manufactured by Beta Products, Part No. 306930.
i r
1 2
SREPt92-118.001
p -
l The Light cllouston ompLight.ing any South
& l'ower Texas l'_r_
_ . Generating acct Electric _ . . . _Station
._ . _,_' .O.Ilon289 l. ...___ Wad worth. Tc m ai 774 81 April 30, 1992 ST-liL- AE- 4 0 6 5 File No.: G02 1 URSO U. S. Nuclear Regulatory Commission Attention: Document Control Desk _
Washington, DC 20555 South Texas Project Unit 2 Docket No. STN 50-499 Supplemental Special Report Regarding Two Diesel Generator N_on-Valid Failures ,
B.
Pursuant to the South Texas Project Electric Generating Station (STPECS) Tech '. ca l Specifications 4.8.1.1.3 and 6.9.2, Houston Lighting & Pove e submits the attached Supplemental Special Report regarding Standby Diesel Generators (SDG) #23 and #21 non-valid failures which occurred on Dscomber 6 and 7, 1991,
- respectively. A Special Report regarding the failure was provided 3, 1992, reference letter ST-HL-AE-3955.
to the NRC on January Please find attached a supplement to that report which provides additional information cor'erning investigative findings. Change bars have been added to highlight supplemental information. _
A separate Special Report regarding a non-valid failure of SDG #21 on December 24, 1991 was provided to the NRC on January 23, 1992, reference letter ST-HL-AE-3985. The attached report also provides additional information for HL&P letter ST-HL-AE-3985 that was due to the NRC by July 30, 1992.
If you should have any questions on this matter, please contact Mr. C. A. Ayala at (512) 972-8629 or myself 7 .
(512) 972-7205.
fhte William J. Jump 4
Manager, Nuclear Licensing JMP/sh Attachtr e nt : Supplemental Special Repert. degarding Two SDG Non-Valid failures SREP\92-b.3.001 A Subudiary of l{ousum NJustries hvorpm.ned
- 3. - q c; { ! (}~ s
~p
4 Ilouston Lighting & Power Company-- , ST-HL-AE-4065 South Texas Project Electric Generating Stanon File No.: G02 Page 2.
cc:
Regional Administrator, Region IV Rufus S. Scott Nuclear Regulatory Commission Associate General Counsel dll Ryan Plaza Drive, Suite 400 Houston Lighting & Power Company Arlington, TX 76011 P. O. Box 61867 Houston, TX 77208 George-Dick,-Project Manager U.S. Nuclear'.. Regulatory Commission INPO Washington, DC 20555. Records Center 1100 Circle 75-Parkway J. I. Tapia.
Atlanta, GA -30339-3064 Senior Resident Inspector c/o;U. S. Nuclear Regulatory Dr. Joseph M. Hendrie
' Commission- 50 Bellport Lano
.P. O. Box 910 Bellport, NY 11713 Bay-City, TX 77434 D. K. Lacker J':R. Newman, Esquire
. Bureau of Radiation Centrol Newman & Holtzinger, P.C. Texas Department of Health 1615 L Street, N.W.- 1100 West 49th Street Washington, DC--20036 Austin, TX 78756-3189 D.-E. -
Ward /T.-M..Puckett Central Power and Light Company P. O. Box 2121 Corpus-Chrinti, TX -78403 J. C. Lanier/M. B. Lee" ._
City _ of Austin Electric' Utility Department
- P.O. Box 1088 ~
. Austin, TX--78767
-X. J. Fiedler/M. T. Hardt City Public Service Board-P. O.-Box 1771 San Antonio, TX 78296-Revised 10/11/91 L4/NRC/
Attachnent ST-IIL-A E-4 0 6 5 Page 1 of 3 South Texas Project Unit 2 DoLKet No. STN 50-499 Supplemental Special Report Regarding Two Diesel Generator Non-Valid Failures DESCRIPTION OF EVEliT:
On December 6, 1991, at 2301 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.755305e-4 months <br />, Standby Diesel Generator
/23 was started in the emergency mode following release of Equipment Clearance Order 2 '61 which was associated with a work document. Unit 2 was in Moce 4 during a refucling outage.
SDG #23 came up to rated speed, voltage, and frequency within 10 seconds. When the engine was released from emergency mode, SDG
/;.3 tripped with no test mode trips indicated. The engine was then restarted at 0030 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> on December 7 in the test mode with I&C, Electrical, and Mechanical Maintenance personnel present. The engine came up to rated speed, voltage, and frequency within the 10 second limit and was running satisfactorily. The engine was then started a third time at 0059 hours6.828704e-4 days <br />0.0164 hours <br />9.755291e-5 weeks <br />2.24495e-5 months <br /> in the emergcncy mode. The dierel generator was released from the emergency modo to the test mode without a trip. The Control Room then commenced the Standby Diesel Generator #23 Operability Test. The diesel performed
. ,atisfactorily during the one hour _ surveillance run and SDG #23 was
+1tclared operable at 0250 hours0.00289 days <br />0.0694 hours <br />4.133598e-4 weeks <br />9.5125e-5 months <br />.
Standby-Diesel Generator /21 was started on December 7, 1991, at 0313 hours0.00362 days <br />0.0869 hours <br />5.175265e-4 weeks <br />1.190965e-4 months <br /> in the emergency mode to verify operability in accordance with Technical Specification Action Statement 3.8.1.1 and came up to rated speed, voltage, and- frequency within 10 seconds. When the engine was released from the emergency mode, SDG #21 tripped with no' test mode trips indicated. SDG #31 was restarted in the emergency mode a second time at 0323 hours0.00374 days <br />0.0897 hours <br />5.340608e-4 weeks <br />1.229015e-4 months <br />, released from the emergency mode to the test mode, and the engine functioned properly. At 0603 hours0.00698 days <br />0.168 hours <br />9.970238e-4 weeks <br />2.294415e-4 months <br />, th2 Control Room commenced SDG /21 operability test and declared SDG /21 operable at 0820 hours0.00949 days <br />0.228 hours <br />0.00136 weeks <br />3.1201e-4 months <br />.
Subsequent troubleshooting was performed on SDG /23 and SDG /21 on February 28, 1992, and January 15, 1992 respectively.
All electrical circuitry pertaining to the 86S relay trip circuit was verified for termination tightness, condition of lugs, and proper termination. In addition, a chart recorder was set up to monitor the 86S trip circuit loop voltages. L abnorcal indications were observed. I&C personnel also inspected the pneumatic control system by monitoring performance with test gauges, but did not disassemble any piping or components. Again, no problems were noted on either diesel.
$2 epi 92-098.001
Attachment ST-HL-AE-4065 Page 2 of 3 DESCRIZf_LON OF EVEST: (Continued)
The 86S relay on SDG #21 was again tested on March 3, 1992. The voltages vore monitored with a chart recorder during operation of the generator. One set of contacts were found to have a slightly out of tolerance resistance measurement. The relay was subsequently replaced. Evaluation of the 86S relay shows that the chance of circuit malfunction would be unlikely with the as-found value of resistance. The conservative approach was to replace the relay, as a considerably higher value of contact resistance (leading to contact failure) could cause this mode of diesel trip.
Inspection of- the pneumatic control circuits on both engines revealed foreign material in check valves SD-3207 (#21) and SD-3209 (123). These check valves prevent reverse airflow from the shutdown control air line into the reset air line. Foreign material-under the seat of these check valves causes a decrease in air line prassure and-at 20 psig, a shuttle valve will change state and cause the engine to trip with no indications, CAUSE OF EVENT The cause of these events can reasonably be attributed to foreign material under the' seat of the check valves allowing a decrease in air pressurof and ultimately causing the trips with no apparent indication.
ANALYSIS OF EVENT:
These two events have been classified as non-valid failures since - the diesel generators operated satisfactorily in the emergeacy mode and if challenged, would have performed their safety
'functlun. SDGs #21 and #23 were started in test mode on December 15, 1991 and both engines operated satisfactorily. Diesel generator /21 also successfully completed a valid test on December
~
19, 1991. SDGs #21 and #23 started and ran in the energency mode when ~ responding to a recent reactor trip and Safety - Injection-signal _on December 24, 1991. SDG /21 tripped when released from the emergency mode during the run on December 24. Subsequently,
'a separate report for this apparent non-valid failure was submitted addressing the cause of the SDG trip, reference letter ST-HL-AE-3985. Since these SDGs have operated correctly in the emergency mode, the diesel generators are considered capable of fulfilling their required safety functions.
SREP\92-098.001
Attachment ST-ItL-AE-4 0 6 5 Page 3 of 3 CORRECTIVE ACTIONfi:
- 1. Troubleshooting for SDG /23 and SDG l'J 1 have been completed.
- 2. Preventive maintenance instructions will be developed to clean the subject check valves periodically. This activity will be completed by July 15, 1992.
ADDITIONAL INFORMATION:
At the time of the event, there were no valid failures in the last 20 valid tests and less than 4 valid failures in the last 100 tests for SDG #21. The testing frequency remained at once per 31 days.
At the time of the event, there were no valid failur.:s in the last 20 valid tests and less than 4 valid failures in the last 100 tests for SDC #23. The testing frequency remailed at once per 31 days.
l i
i
~
l l
l l-F f
l l
I-SREP\92-093.001