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Issue date | Title | Topic | |
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ML19291C264 | 8 September 1975 | AO 73-19:when Closing Signal Was Applied to Breaker S1A,loss of Power Occurred at 4160-volt Ac Bus 1A Causing Trip of Various Pumps.Caused by Incorrect Setting of Current Transformer Ratio Matching Taps.Taps Set Properly | |
ML19291C282 | 15 March 1974 | AO 50-219/74/17:on 740307,during Transfer of Power from Auxiliary to Startup Transformer,Closing Switch for Breaker S1B Would Not Operate.Caused by Component Failure of Closing Spring Not Being in Charged Position | |
ML19343C218 | 23 December 1975 | AO 50-219/75-33:on 751212,during 6-month Load Test on Station a batteries,125 Volt Dc Distribution Ctr de-energized.Caused by Personnel Error in Following Procedure.Distribution Ctr re-energized | |
ML19343C219 | 11 December 1975 | AO 50-219/75-32:on 751203,during Testing,Emergency Diesel Generator 1 Failed to Start When Simulated Loss of Power Condition Applied to Fast Start Logic Circuit.Caused by Failure of Relay to Operate Due to Varnish on Armature | |
ML19343C220 | 26 July 1974 | AO 50-219/74/41:on 740719,main Steam Line Low Pressure Switches RE23C & D Tripped at Pressures Less That Min Required Value of 860 Psig.Caused by Lack of Setpoint Tolerances.Setpoint Accuracy & Tolerance Being Investigated | Fuel cladding |
ML19343C221 | 25 July 1974 | AO 50-219/74/42:on 740725,main Steam Line Low Pressure Switches RE23A,B,C & D Tripped at Pressures Less than Min Required Value of 860 Psig.Caused by Switch Repeatability. Setpoint Accuracy & Tolerance Under Investigation | Fuel cladding |
ML19343C222 | 24 July 1974 | AO 50-219/74/40:on 740715,insp Located Inoperable Bergen- Paterson Hydraulic Shock & Sway Arrestor on South Core Spray Sys in Drywell.Caused by Loss of Hydraulic Fluid Due to Burns on Main Control Rod.Units Replaced | Earthquake |
ML19343C223 | 23 July 1974 | AO 50-219/74/39:on 740714,electromatic Relief Valve Pressure Switches 1A83A,1A83B,1A83C & 1A83E Tripped at Pressures in Excess of Max Allowable Value of 1,070 Psig.Caused by Lack of Allowance for Setpoint Tolerances in Tech Specs | |
ML19343C224 | 19 July 1974 | AO 50-219/74/37:on 740712,main Steam Line Low Pressure Switches RE23A,B,C & D Tripped at Pressures Less than Min Required Value of 860 Psig.Caused by Switch Repeatability. Setpoint Accuracy & Tolerance Under Investigation | Fuel cladding |
ML19343C225 | 15 July 1974 | AO 50-219/74/35:on 740705,main Steam Line Low Pressure Switches RE23B,C & D Tripped at Pressure Less than Min Required Value of 860 Psig.Caused by Switch Repeatability. GE Requested to Investigate Feasibility of Tech Specs Mod | Fuel cladding |
ML19343C226 | 11 July 1974 | Addendum to AO 50-219/74/28 Dtd 740426:on 740419,motor- Operated Valve V-20-4 Failed to Open Electrically After Closing Electrically.Caused by Premature Opening of Position Switch 20-C.Position Switch Readjusted | |
ML19343C229 | 7 June 1974 | AO 50-219/74/34:on 740529,coolant Leakage Found in Area of Incore Flux Monitor Reactor Vessel Housing at Core Coordinate 28-05.Cause Undetermined.Insp Program Developed to Examine Incore Flux Monitor Tube from Below Vessel | Hydrostatic |
ML19343C351 | 31 May 1974 | AO 50-219/74/32:on 740521,relay 16K114D in Sys 2 Core Spray Booster Pump Initiation Logic Found in Energized Position. Caused by Failed Core Spray Booster Pressure Switch RV40D. Relay Placed in de-energized Position by Valving Out Switch | |
ML19343C352 | 1 May 1974 | AO 50-219/74-28:on 740423,suction Valve V-20-4 to B Core Spray Pump Stuck in Closed Position for 15 Minutes,Causing Loss of Core Spray Redundancy in Sys 2.Cause Undetermined. Valve Manually Closed & Circuit Breaker Tagged Open | |
ML19343C353 | 31 May 1974 | AO 50-219/74/33:on 740521,auto-depressurization Sys Initiation Timers 16M23A & 16M232B Failed to Complete Timing Cycle in Less than Two Minutes.Cause Under Investigation. Timers Reset & Timed Out in Less than Two Minutes | |
ML19343C354 | 29 May 1974 | AO 50-219/74/31:on 740519,Bergen-Paterson Hydraulic Shock & Sway Arrestor Located on South Core Spray Sys Found Inoperable.Caused by Loss of Hydraulic Fluid.Units Replaced W/Units Equipped W/Emergency Preparedness Seals | Design basis earthquake |
ML19343C355 | 23 May 1974 | AO 50-219/74/30:on 740514,pressure Switch PSH-C Failed to Trip at Nominal Trip Pressure of 180 Psig.Cause Under Investigation.Switch Recalibr & Tested Satisfactorily | |
ML19347C795 | 29 January 1974 | AO 50-219/74/8:on 740117,isolation Condenser Sys Initiation Time Delay Switch Failed to Close within Tech Specs Time Limit After High Reactor Pressure Reached.Caused by Instrument Drift.Research Initiated to Clarify Requirements | |
ML19347C796 | 28 January 1974 | AO 50-219/74/7:on 740123,during Monthly Surveillance Test, Reactor High Pressure Sensor RE03D Failed to Trip at Point Corresponding to Reactor Pressure of 1,060 Psig.Caused by Design Error.Pressure Sensor Recalibr & Returned to Svc | |
ML19347C797 | 28 January 1974 | AO 50-219/74/6:on 740122,24-h After Placing Mode Selector Switch Into Run,Torus Atmosphere Contained 6.2% Dioxide in Excess of Tech Specs Limit of 5.0%.Caused by Operator Error & Late Nitrogen Truck Delivery | |
ML19347C798 | 25 January 1974 | AO 50-219/74/8:on 740117,during Surveillance Test,Isolation Condenser Sys Initiation Switches Time Delays Failed to Close within Tech Specs Limt of 15-s.Caused by Design Error & Instrument Drift.Plant Committee Reviewing Occurrence | |
ML19347C799 | 25 January 1974 | AO 50-219/74/5:on 740116,MSIV NS04A Failed to Meet Allowable Leakage Requirement.Caused by Failure of Packing Ground Valve Shaft.Valve Shaft Repacked & Valve Retested Successfully | |
ML19347C800 | 25 January 1974 | AO 50-219/74/4:on 740116,while Reactor Shut Down for Maint Work W/Mode Switch in Refuel,Msiv NS03B Failed to Close on Manual Signal.Caused by Pilot Valve Design & Oxide Residue on Valve Spools & Sleeves | Overtravel |
ML19347C801 | 24 January 1974 | AO 50-219/74/3:on 740113,during Insp of Bergen-Paterson HSSA-10 Units in Primary Containment Hydraulic Shock & Sway Arrestors Found Devoid of Fluid.Cause Under Study.Units Replaced W/Units Rebuilt W/Ethylene Propylene Seal Matl | |
ML19347C802 | 23 January 1974 | AO 50-219/74/6:on 740122,24-h After Placing Mode Selector Switch Into Run,Torus Atmosphere Contained 6.2% Dioxide in Excess of Tech Specs.Caused by Operator Error & Late Nitrogen Truck Delivery.Corrective Actions Being Studied | |
ML19347C803 | 7 January 1974 | Ao:On 731218-20,test Spool Valve for MSIV NS04A Failed to Properly Reset & Experienced Pressure Transients During & After 5% Closure Test.Caused by Faulty Operation of Test Valve & Improper Valve Resetting | Overtravel |
ML19347C804 | 14 January 1974 | AO 50-219/74/3:on 740113,during Insp of Bergen-Paterson HSSA-10 Units Primary Containment Hydraulic Shock & Sway Arrestors Found Devoid of Fluid.Cause Under Study.Units to Be Replaced W/Units Rebuilt W/Ethylene Propylene Seal Matl | |
ML19347C806 | 14 January 1974 | AO 50-219/74/1:on 740104,low Pressure Main Steam Line Pressure Switch Trip Setpoint of 850 Psig Determined Incorrect & in Violation of Tech Specs.Caused by Design, Procedure & Unusual Svc Condition | Fuel cladding |
ML19347C807 | 6 December 1973 | AO 73-30:on 731206,main Steam Line Low Pressure Switches RE23A Through RE23D Tripped at Pressure Below Min Setpoint of 850 Psig.Cause Undetermined.Switches Reset.Mfg Conducting Study W/Ge to Investigate Setpoint Drift | Fuel cladding |
ML19347C808 | 9 January 1974 | Ao:On 731227,during Quarterly Calibr Test of Main Steam Line High Radiation monitors,RN05A Log Count Rate Monitor Failed to Trip at Normal Setpoint of 1,000 Cps.Caused by Cold Soldered Connection in High Alarm Trip Section of Assembly | Half scram |
ML19347C809 | 9 January 1974 | AO 50-219/74/2:on 740108,RE22C & RE22E Main Steam Line High Flow Sensors Actuated Above Max Allowable Tech Specs Pressure Levels.Cause Being Investigated.Sensors Recalibr & Returned to Svc as Failures Discovered | |
ML19347C810 | 4 January 1974 | Ao:On 731221,four Isolation Condenser High Flow Sensors Failed to Trip on Delta P Values During Surveillance Testing Due to Setpoint Drift.Cause of Setpoint Drift Investigated. Sensors Reset & Procedures Reviewed | |
ML19347C811 | 3 January 1974 | Ao:On 731220,3,400 Gallons of Contaminated Radioactive Chromated Water Spilled.Caused by Crack in Drain Line Due to Severely Cold Weather.Contaminated Water Pumped Into Ground Containers.Shallow Wells Being Drilled for Analyses | |
ML19347C812 | 2 January 1974 | Ao:On 731125,during Reactor Cooldown Operation,Unexplained Isolation of Isolation Condenser B Occurred.Caused by Slow Instrument Response Due to Defective Snubbers.Snubbers Replaced & Pressure Decay Tests Established | |
ML19347C813 | 24 December 1973 | Ao:On 731206,Meletron Corp Model 372,main Steam Line Low Pressure Switches RE23A Through RE23D Found to Trip at Pressure Below Min Required Setpoint of 850 Psig.Cause of Setpoint Drift Under Study.Switches Reset | Fuel cladding |
ML19347C814 | 24 December 1973 | Ao:On 731213,momentary Interruption of 125 Volt Power Supplying Instrumentation to Panel E Safeguard Sys Occurred. Caused by Improper Placement of Jumper Used to Parallel a & B Distribution Buses.Automatic Reset Function Restored Svc | |
ML19347C815 | 20 December 1973 | Ao:On 731121,relay 6K43 de-energized When Smoke Observed Emanating from Panel 10F Control Room.Cause Undetermined. Relay 6K43 Removed for Testing.New Relay of Higher Voltage Installed.Further Action Considered Based Upon Insp Results | |
ML19347C816 | 13 November 1973 | Ao:During Insp of Bergen-Paterson HSSA-10 Units on Steam Line B Isolation Condenser NE01B,hydraulic Shock & Sway Arrestors Found Devoid of Fluid.Cause Under Study.Units Will Be Replaced W/Units Rebuilt W/Ethylene Propylene Seal Matl | Earthquake |
ML19347C817 | 8 November 1973 | Ao:On 730914,leakage Occurred from Reactor Bldg Closed Cooling Water Sys to Discharge Canal Via Svc Water Sys. Caused by Leaking Tubes in Reactor Bldg Closed Cooling Water Heat Exchanger 1-2.Investigation Continuing | |
ML19347C818 | 16 October 1973 | AO 73-26:on 731010,average Power Range Monitor Scram & Rod Block Setpoints Not Set to Conservative Values Specified in Tech Specs.Caused by Personnel Error.Procedures Will Be Reviewed W/Personnel | |
ML19347C819 | 12 October 1973 | Ao:On 730928,MSIV,NS04A & NS04B Failed to Meet Allowable Leakage Requirement.Caused by Failure of Valve Stem Packing. MSIV Repacked & Tested Satisfactorily | |
ML19347C820 | 9 October 1973 | Ao:On 730929,during Surveillance Test on Reactor High Pressure Isolation Condenser Initiation Switches,Contacts on Agastat Relay 6K12 Failed to Close within Preset Time Delay of 15-s.Cause Unknown.Relay 6K12 Replaced W/New Relay | |
ML19347C821 | 21 September 1973 | Ao:On 730908,during Leakage Rate Test MSIV NS03B Failed to Meet Acceptable Leakage Rate Criterion Per Tech Specs.Cause Unknown.New Procedures Established Before & After Disassembly of NS03B.Analysis Continuing | |
ML19347C822 | 21 September 1973 | Ao:On 730908,plant Shut Down to Inspect Hydraulic Shock & Sway Arrestors on Piping Sys in Drywell Bldg.Insp Revealed 23 Failed Arrestors.Caused by Loss of Hydraulic Fluid from Failed Millable Gum Polyurethane Seals | Earthquake |
ML19347C823 | 18 September 1973 | Ao:On 730908,1A 4,160 Volt Ac Bus Lost Power Causing Two Circulating Water Pumps,Three Reactor Recirculation Pumps, & Operating Condensate & Feedwater Pumps to Trip.Caused by Improper Tap Setting of Transformer Ratio on C Relay | |
ML19347C824 | 18 September 1973 | Ao:On 730910,isolation Condenser NE01A Condensate Return Valve V-14-34 Failed to Operate During Plant Cooldown.Cause Not Stated.Overloads Found Tripped Were Reset & New Overloads Installed.Weekly Surveillance Test Initiated | |
ML19347C825 | 10 September 1973 | AO 73-22:on 730909,MSIV NS03B Tested for Leakage & Found to Exceed Tech Specs Limit.Cause Unknown.Prior to Disassembly of Valve,Stem Measurements Taken on All Valves to Check Conformity | |
ML19347C826 | 10 September 1973 | AO 73-21:on 730908,during Plant shutdown,21 Hydraulic Shock & Sway Arrestors in Piping Sys in Drywell Found Failed. Caused by Loss of Hydraulic Fluid.Failed Snubbers Replaced W/Snubbers Rebuilt w/Bergen-Paterson Seal Kits | Earthquake |
ML19347C827 | 10 September 1973 | AO 73-20:on 730909,isolation Condenser NE01A Condensate Return Valve V-14-34 Failed to Operate During Last Stages of Plant Cooldown.Caused by Tripped Overloads on Starting Contactor.Overloads Reset | |
ML19347D308 | 3 October 1973 | Ao:On 730924,during Surveillance Testing,Differential Pressure Switch DPS66A Failed to Trip.Caused by Excess Friction in Linkage Pivots.Switch Removed,Disassembled & Cleaned |