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| Issue date | Title | Topic | |
|---|---|---|---|
| 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 | |
| ML20090C999 | 12 December 1975 | AO 75-33:on 751212,125-volt Dc Distribution Ctr of Station a Battery Inadvertently de-energized.Caused by Failure to Establish Proper Breaker Lineup Preparation for Conducting Battery Load Test.Procedure changed.W/751219 Memo | |
| 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 | |
| ML20126E828 | 3 December 1975 | AO 50-219/75-31:on 751124,during Operability Test of Torus to Drywell Vacuum Breakers,Alarm Sys 2 Failed to Annunciate in Control Room When V-26-4 Opened.Caused by Failure of Relay Due to Contacts Being Detective.Relay Replaced | |
| ML20090D007 | 25 November 1975 | AO 75-31:on 751124,drywell Vacuum Breaker Alarm Sys II Failed to Annunciate When Vacuum Breaker V-26-4 Opened. Caused by Component Failure.Corrective Action Under Investigation | |
| ML20090D016 | 7 November 1975 | AO 75-30:on 751106,low Reactor Pressure Core Spray Valve Permissive Pressure Switches Re 17 a & C Tripped at Pressure Less than Min Required Value.Caused by Switch Repeatability.Pressure Switches Recalibr | |
| ML20090D060 | 6 November 1975 | AO 75-29:on 751027,torus Drywell Vacuum Breakers Alarm Sys II Failed to Annunciate When Vacuum Breaker V-26-8 Opened. Caused by Sticking Microswitch | |
| ML20090D076 | 28 October 1975 | AO 75-29:on 751027,torus to Drywell Vacuum Breaker Alarm Sys II Failed to Annunciate When Vacuum Breaker V-26-8 Opened.Caused by Component Failure.Corrective Action Under Investigation | |
| ML20090D094 | 24 October 1975 | AO 75-28:on 751015,standby Gas Treatment Sys 1 Inoperable. Caused by Air Solenoid Valve Coil Failure.Defective Solenoid Coil Replaced | |
| ML20090D114 | 17 October 1975 | AO 75-27:on 751008,low Reactor Pressure Core Spray Valve Permissive Pressure Switches RE17B & D Tripped at Pressure Less than Min Required Value.Caused by Switch Repeatability. Pressure Switches Recalibr | |
| ML20090D104 | 16 October 1975 | AO 75-28:on 751015,standby Gas Treatment Sys 1 Inoperable. Caused by Air Solenoid Valve Coil Failure.Defective Solenoid Coil replaced.W/751016 | |
| ML20090D134 | 8 October 1975 | AO 75-27:on 751008,low Reactor Pressure Core Spray Valve Permissive Pressure Switches RE17B & D Tripped at Pressures Less than Min Required Value.Caused by Switch Repeatability. Pressure Switches Recalibr | |
| ML20090D150 | 23 September 1975 | AO 75-26:on 750923,emergency Svc Water Pump 52C Failed to Start Automatically During Routine Surveillance Test of Containment Spray Sys Ii.Caused by Failure of Contact Switch in Time Delay Relay 16 K4B.Relay Replaced | |
| 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 | |
| ML20090D194 | 8 September 1975 | AO 75-25:on 750829,stack Gas Sample Sys Failed to Monitor Stack Releases Continuously While Reactor Was in Unisolated Condition.Caused by Malfunctioning Pump Lubricator.Thermal Overload Protection Reset | |
| ML20090D207 | 8 September 1975 | AO 75-24:on 750829,electromatic Relief Valve Pressure Switches 1A83C & 1A83D Tripped at Pressures in Excess of Max Allowable Value.Caused by Instrument Setpoint Repeatability. Switches Reset | |
| ML20090D201 | 2 September 1975 | AO 75-25:on 750829,stack Gas Sample Sys Failed to Monitor Stack Releases Continuously While Reactor Was in Unisolated Condition.Caused by Malfunctioning Pump Lubricator.Thermal Overload Protection Reset | |
| ML20090D215 | 2 September 1975 | AO 75-24:on 750829,electromatic Relief Valve Pressure Switches 1A83C & 1A83D Tripped at Pressures in Excess of Max Allowable Value.Caused by Instrument Setpoint Repeatability. Switches Reset | |
| ML20090D224 | 21 August 1975 | AO 75-23:on 750817-20,stack Effluent for Iodine & Particulates Not Monitored.Caused by Personnel Error.Filter Installed in Operating Stack Gas Sampling Train | |
| ML20090D226 | 11 August 1975 | Preliminary AO-50-219/75-22:on 750810,stack Gas Sample Line Low Flow Alarm Received.Caused by Stack Gas Sample Pump a Not Running.Thermal Overload Protection Reset | |
| ML20090D247 | 4 August 1975 | Preliminary AO-50-219/75-21:on 750801,during Routine Surveillance on B Isolation Condensor Sys,Steam Line Valve V-14-32 Failed to Close on Simulation of Steam Line High Flow.Caused by Low Torque Switch Setting.Torque Increased | |
| ML20090D252 | 17 July 1975 | AO 50-219/75-19:on 750708,during Monthly Surveillance Test on Reactor High Pressure Scram Sensors,Re 03A,B,C & D, A,B & D Tripped Above Normal Trip Points.Caused by Switch Repeatability.Sensors Recalibr | |
| ML20085E955 | 9 July 1975 | AO BFAO-50-260/759T:on 750709,broken Stem Found on second- Stage Pilot of Main Steam Release Valve 1.Break Point Just Under Lock Nut Above Actuating Piston.Site Inspector Advised | |
| ML20090D256 | 9 July 1975 | Preliminary AO 50-219/75-19:on 750708,during Monthly Surveillance Test on Reactor High Pressure Scram Sensors,Re 03A,B,C & D,A,B & D Tripped Above Normal Trip Points.Caused by Switch Repeatability.Sensors Recalibr | |
| ML20084E115 | 1 July 1975 | RO 50-219/75-18:on 750623,two 8-1/2 Inch Handhole Covers in Standby Gas Treatment Filter Train Not in Place.Cause Unknown.Handhole Covers Repositioned & Secured | |
| ML20090D274 | 27 June 1975 | AO 50-219/75-17:on 750619,during Surveillance Test,Core Spray Sys Parallel Isolation Valve V-20-15 Failed to Demonstrate Operability.Caused by Broken Tab on B Phase of Valve Motor Breaker Stab.Stab Replaced | |
| ML20090D278 | 24 June 1975 | AO 50-219/75-16:on 750614,electromatic Relief Valve Pressure Switches 1A83P & E Tripped at Pressures Exceeding Tech Spec Limit.Caused by Instrument Setpoint Drift.Switches Reset | |
| ML20090D266 | 24 June 1975 | Preliminary AO 50-219/75-18:on 750623,handhole Covers in Standby Gas Treatment Filter Train 1-1 Not in Place.Cause Under Investigation.Covers Repositioned & Secured | |
| ML20090D273 | 19 June 1975 | Preliminary AO 50-219/75-17:on 750619,during Surveillance Test,Core Spray Sys Parallel Isolation Valve V-20-15 Failed to Demonstrate Operability.Caused by Broken Tab on B Phase of Valve Motor Breaker Stab.Stab Replaced | |
| ML20090D290 | 16 June 1975 | Preliminary AO 50-219/75-16:on 750614,electromatic Relief Valve Pressure Switches 1A83B & E Tripped at Pressure Exceeding Tech Spec Limit.Caused by Instrument Setpoint Drift.Switches Reset | |
| ML20090D656 | 6 June 1975 | AO-50-219/75-14:on 750529,during Surveillance Test of Containment Spray Pump Operability,Essential Svc Water Pump 1-2 Failed to Develop Sufficient Discharge Pressure.Caused by Dirt in Check Valve V-3-68.Valve Cleaned & Repaired | |
| ML20090D297 | 6 June 1975 | AO 50-219/75-15:on 750530,calculations of TIP Traces Indicated Total Peaking Factor in One Core Location in Excess of Value of Pf Given in Tech Specs.Caused by Lack of Operating Experience W/New Core Loading | |
| ML20090D298 | 2 June 1975 | Preliminary AO 50-219/75-15:on 750530,calculations of TIP Traces Indicated Total Peaking Factor in One Core Location in Excess of Value of Pf Given in Tech Specs.Caused by Lack of Operating Experience W/New Core Loading | |
| ML20090D658 | 30 May 1975 | Preliminary AO-50-219/75-14:on 750529,during Surveillance Test of Containment Spray Pump Operability,Essential Svc Water Pump 1-2 Failed to Develop Sufficient Discharge Pressure.Caused by Dirt in Check Valve V-3-68.Valve Cleaned | |
| ML20090D661 | 14 May 1975 | AO-50-219/75-13:on 750507,during Surveillance Test,Time Delay Relay 6Kll Failed to de-energize within 15 After Pressure Sensor RE-15C Tripped.Caused by Component Failure.Relay 6Kll Replaced | |
| ML20090D664 | 7 May 1975 | Preliminary AO-50-219/75-13:on 750507,during Surveillance Test,Time Delay Relay 6Kll Failed to de-energize within 15 After Pressure Sensor RE-15C Tripped.Caused by Component Failure.Relay 6Kll Replaced | |
| ML20090D653 | 6 May 1975 | AO-50-219/75-12:on 750426,low Reactor Pressure Core Spray Valve Permissive Pressure Switches Re 17B & C Found to Trip at Pressure Less than Tech Spec Value.Caused by Switch Repeatablilty.Switches Recalibr | |
| ML20090D670 | 28 April 1975 | Preliminary AO-50-219/75-12:on 750426,low Reactor Pressure Core Spray Valve Permissive Pressure Switches Re 178 & C Found to Trip at Pressure Less than Tech Spec Value.Caused by Switch Repeatability.Switches Recalibr | |
| ML20090D675 | 18 April 1975 | AO-50-219/75-11:on 750410,leakage of Main Line Drain & Bypass Line Exceeded Tech Spec Rate.Caused by Failure of Packing on Valve V-1-110.Valve to Be Repacked | |
| ML20090D700 | 14 April 1975 | AO-50-219/75-10:on 750404,reactor Bldg to Torus Vacuum Breaker Valves V-26-16 & 18 Leak Rates Exceeded Tech Spec Limits.Caused by Component Failure.Valves Adjusted &/Or Repaired | |
| ML20090D681 | 11 April 1975 | Preliminary AO-50-219/75-11:on 750410,leakage of Main Line Drain & Bypass Line Exceeded Tech Spec Rate.Caused by Failure of Packing on Valve V-1-110.Valve to Be Repacked | |
| ML20090D713 | 8 April 1975 | AO-50-219/75-09:on 750329,breaker 1C Tripped Resulting in Fault on Bus 1C.Caused by Fault on Cable 86-25.Cables Replaced | |
| ML20090D706 | 7 April 1975 | Preliminary AO-50-219/75-10:on 750404,reactor Bldg to Torus Vacuum Breaker Valves V-26-16 & 18 Leak Rates Exceeded Tech Spec Limits.Caused by Component Failure. Valves Adjusted &/Or Repaired | |
| ML20090D727 | 3 April 1975 | AO-50-219/75-08:on 750325,power Operation Continued W/ Average Linear Heat Generation Rate of Fuel Assemblies in Excess of Max Linear Heat Generation Rate.Caused by Failure to Properly Monitor Reactor Core.Rate Reduced | |
| ML20090D721 | 31 March 1975 | Preliminary AO-50-219/75-09:on 750329,breaker 1C Tripped Due to Fault on Bus 1C.Caused by Fault on Cable 86-25.Cables Replaced | |
| ML20090D765 | 27 March 1975 | AO-50-219/75-07:on 750319,during Standby Gas Treatment Sys (SGTS) Test,Dehumidifying Heater EHC-1-5 in SGTS 1 Failed to Energize.Caused by Plugged Orifice in Air Supply to Controller.New Type of Differential Relay Installed | |
| ML20090D736 | 26 March 1975 | Preliminary AO-50-219/75-08:on 750325,power Operation Continued W/Average Linear Heat Generation Rate of Fuel Assemblies in Excess of Max Linear Heat Generation Rate. Caused by Improper Reactor Core Monitoring.Rate Reduced | |
| ML20090D776 | 20 March 1975 | Preliminary AO-50-219/75-07:on 750319,during Stanby Gas Treatment Sys (SGTS) Test,Dehumidifying Heater EHC-1-5 in SGTS 1 Failed to Energize.Caused by Plugged Orifice in Air Supply to Controller.New Type of Relay Installed | |
| ML20090D780 | 19 March 1975 | AO-50-219/75-06:on 750310,stack Gas Sample Sys Failed to Continuously Monitor Stack Releases While Reactor in Unisolated Condition.Caused by Circuit Design.Request to Modify Circuit for Stack Gas Sample Pumps Submitted | |
| ML20090D790 | 13 March 1975 | AO-50-219/75-05:on 750306,during Monthly Surveillance Test, Containment Spray Pump 51A Failed to Start When Subjected to Simulated Signals.Caused by Breaker Trip Bar Failing to Reset After Previous Breaker Trip.Trip Bar Bushings Cleaned |