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Issue date | Title | Topic | |
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ML20086D557 | 29 September 1977 | Telecopy Ro:On 770929,local Leak Rate Testing of Core Spray Inboard Isolation Check Valve AO-14-13A Indicated That Leakage Exceeded Tech Spec Acceptance Criteria.Cause Under Investigation | |
ML20086D561 | 14 September 1977 | Telecopy Ro:On 770913,local Leak Rate Testing of Core Spray Inboard Isolation Check Valve AO 14-13B Indicated That Leakage Exceeded Tech Spec Acceptance Criteria.Related Event on 770914 | |
ML20086D567 | 12 September 1977 | Telecopy Ro:Main Steam Drain Isolation Valve MD 2373 & Main Steam Outboard Isolation Valve AO 2-86A Exceeded Tech Spec Acceptance Criteria for Local Leak Rate Tests | |
ML20086D642 | 11 July 1977 | Telecopy Ro:On 770709,determined That Recombiner Sys a Offgas Flow Control Valve PCV 7489A Could Be Opened W/ Controlling Solenoid Valve Deenergized.Valve Held from Svc Pending Investigation | |
ML20086D691 | 2 March 1977 | Telecopy Ro:On 770301,torus Water Vol Found to Be Slightly Below Min Vol Established by Tech Specs.Water Vol Restored to Normal Operating Level | |
ML20086D703 | 24 February 1977 | Telecopy Ro:On 770223,while Withdrawing in-sequence Control Rod to Bring Reactor Critical,Reactor Period of Less than 5 Obtained | |
ML20086D788 | 10 September 1976 | Telecopy Ro:On 760909,discovered That Torus Water Vol Several Hundred Cubic Ft Below 68,000 Cubic Ft Min Required by Tech Specs.Caused by Failure to Correct for Vol Vs Level Correlation | |
ML20086D823 | 5 May 1976 | Telecopy Ro:On 760504,during Routine Surveillance Test, Primary Containment Oxygen Concentration Found to Be in Excess of Tech Spec Limit.Caused by Leakage from Drywell Instrument Air Sys Into Containment Nitrogen Supply Line | |
ML20086F080 | 6 June 1977 | Ro:On 770506,plant Iodine & Particulate Release Rate Exceeded 4% of Facility Tech Spec Averaged Over Second Calendar Quarter of 1977.Caused by Fuel Perforations Coupled W/End of Cycle Testing & Reactor Coolant & Steam Leaks | Fuel cladding |
ML20086F418 | 9 December 1976 | RO Re Plant Iodine & Particulate Release Rate Exceeding 4% of Tech Spec 3.8.C.2 Averaged Over Fourth Calendar Quarter 1976.Caused by Leaks in Reactor Water Cleanup Sys.Leaks Repaired & Equipment Modified to Reduce Leakage | |
ML20086F470 | 27 January 1976 | Ro:On 760117,gaseous Activity Release Rate Exceeded 4% of Tech Spec 3.8.C.1 for More than 48 H.Caused by Increase in Offgas Activity Due to Fuel Cladding Perforations | Fuel cladding Power change |
ML20086F473 | 23 December 1975 | Ro:On 751123,during Insp of Upper Portions of Drywell,Two of Eight Reactor Vessel Stabilizers Appeared to Have Been Slightly Deformed.Caused by Stabilizer Bindup & Cyclic Loading During Vessel Heatup or Cooldown | |
ML20090D425 | 20 April 1972 | Ro:On 720411,supply Dampers for Reactor Bldg Ventilation Sys Failed to Close.Caused by Shorted Motor Due to Electrical Problem in Supply Fan 1-13 & racked-out Supply Breaker. Circuit Design Change Will Be Implemented | |
ML20090D429 | 6 October 1972 | Ro:On 720925 & 26,standby Liquid Control Pump Discovered Inoperable.Caused by racked-out Circuit Breaker.Operating Procedures Changed | |
ML20090D487 | 17 January 1973 | Ro:On 721229,turbine Trip & Anticipatory Reactor Scram Initiated When Operator Opened Cabinet Door Carrying Protective Fuses for Generator Monitoring Relays.Caused by Open Pilot Valve for Electromatic Relief Valve D | Breakaway torque |
ML20090D672 | 20 January 1972 | Ro:On 711213,unit Tripped Offline During Surveillance Testing.Sensor Support Accidentally Bumped Causing High Level Trip Sensor to Operate Resulting in Turbine Trip. Review of Expected Sys Responses Given to Operators | |
ML20101M849 | 10 December 1984 | Ro:On 841203,wide-range Log Channel Malfunctioned,Resulting in Manual Scram.Cause Traced to Resistor in Filter on Detector High Voltage Supply.Repairs & Testing in Progress | |
ML20105D243 | 24 June 1983 | Special Rept:Five Individuals Found to Have Received Radiation in Excess of 10CFR20.101 Limits W/O Required Documentation.Caused by computer-based Sys Feature Allowing Use of Outdated Info & Personnel Error.Procedures Revised | High Radiation Area Locked High Radiation Area |
ML20114B322 | 14 January 1985 | Ro:On 850107,while Taking Unit to 95 Kw Power,Period Meter Indicated Period Decreasing W/Log Power Trace Levelling & Linear Power Trace Rising.Caused by wide-range Log Channel Malfunction.Manual Scram Initiated & Reactor Secured | |
ML20136H329 | 13 November 1985 | Ro:On 851112,wide-range Log Channel Malfunctioned During Operation of Reactor.Caused by Faulty Calibr Switch in Log Channel.Switch Adjusted & Reactor Operated at Several Power Levels Up to 95 Kw | |
ML20137G446 | 23 June 1977 | Ro:On 770621,radioactive Source Containing 200 Mci Cs-137 Recovered from Brine Well 33.Incident Described in | |
ML20137G450 | 24 March 1981 | Ro:During walk-through of Operator Training Program, O-ring Seal of Filter Holder Found Not Seated Properly Causing Partial Bypass of Filter for Air Sucked Into instrument.Filter-in Lock Adjusted | |
ML20137G793 | 22 November 1971 | Ro:On 711022,during Startup of Reactor,Period Limiting Signal Unavailable for Servo Sys Which Continued to Raise Rod Causing Rapid Rise of Power.While Reactor Manually Scrammed,Reactor Period Less than Min Allowed in Tech Specs | |
ML20137G816 | 16 February 1973 | Ro:On 730125,available Excess Reactivity of Core Exceeded Tech Specs Limit.Caused by Change in Worth of Control Rods. Rearrangement of Core Configuration Initiated to Reduce Available Excess Reactivity | |
ML20137H384 | 12 January 1976 | Ro:On 760106,operator Left Console Key in Switch So That Reactor Not Secured Per Tech Specs.Key Withdrawn from Console.Incident Discussed W/Operators & Large Red Plastic Tag Attached to Key to Make It More Visible | |
ML20198H369 | 14 November 1983 | Ro:On 831003,results of as-found Tests Indicated Crosby Main Steam Relief Valves Had Lift Points Exceeding Tech Spec Limits.Valves Disassembled & Rebuilt by Mfg | |
ML20206K709 | 2 November 1972 | Unusual Occurrence UO-72-6:on 720924 & 29,out-of-svc Condition of Primary Sys Boundary Coolant Leakage Air Sampling Sys Occurred.Caused by Moisture Accumulating in Detection Equipment.Mod to Equipment Designed | |
ML20211E073 | 26 September 1986 | Unplanned Operating Event Rept 85-6, Manual Reactor Trip Following MSIV Closure Due to Inadvertent Emergency Feedwater Actuation,851009 | |
ML20211K821 | 18 June 1986 | Special Rept:On 860521,valid Failure Occurred on Div 2 Diesel Generator During Performance of Tech Spec Surveillance 4.8.1.1.2.Caused by Failure of Jacket Water Thermostatic Control Valve to Open | |
ML20212Q697 | 26 August 1986 | Ro:On 860821,during Prestartup,Source Interlock Operated But Failed to Prevent Movement of Control Rods.Caused by Temporary Loss of Electrical Contact in Logic Circuits. Movement Restored Proper Electrical Contact | |
ML20215H509 | 16 August 1972 | Ro:On 720727,during Shutdown,Two Employees Injured When Steam Vent Sys Malfunctioned.Caused by Decay Heat Release Piping Disengaging from Piping Support Sys.Workers Treated for Burns.Design Change Investigated.News Release Encl | |
ML20235C899 | 28 April 1971 | Ro:On 710422,HPCI Sys Declared Inoperable & Taken Out of Svc Due to Minor Steam Leaks.During Maint,Lubrication & Control Oil Sys Found Dirty.Leaks Repaired & Oil Sys Cleaning & Flushing Will Be Done.Sys Should Be Operable by 710505 | |
ML20235D063 | 30 April 1971 | Ao:On 710422,during Analysis of Loss of Offsite Power Test Data,Initiation Setpoints of Four RCS Safety/Relief Valves Possibly in Excess of Tech Specs Limit Noted.Caused by Effect of Temp.Calibr Checks Done & Valve Settings Adjusted | |
ML20235D252 | 29 April 1971 | Ro:On 710420,determined That Two Air Ejector off-gas Monitors Have Been Inoperable During Startup Testing Program to 25% Power Level.Caused by Improper Hookup of Ejector Sample Chamber Purge Valve.Sys Piped Up Properly | Grab sample |
ML20235D617 | 19 May 1971 | Aos:On 710420,26 & 0502,condenser Pressure Switches Isolated,Msiv Closed Too Slowly & Automatic Pressure Relief Sys Fuses Found Missing,Respectively.All Conditions Corrected | |
ML20235D896 | 11 June 1972 | Ro:On 720609,w/reactor in Shutdown Mode,Northeast Expansion Joint on Condenser Circulating Water Sys Ruptured.Unit 2 Reactor in Startup Mode & Shut Down Immediately | |
ML20235D999 | 15 September 1971 | Ro:On 710904,during Monthly HPCI Operability Test,Steam Line Isolation Valve Tripped from False High Steam Flow Signal. Caused by Increase in Flow Elbow Differential Pressure.Flow Elbow Sensing Lines Backflushed & HPCI Sys Tested | |
ML20235E027 | 3 July 1972 | Ro:On 720702,RCIC Manually Aligned to Inject Into Reactor. Final Injection Valve MO-1-1301-49 Failed to Open.Reactor Shut Down W/All Rods in | |
ML20235E034 | 24 September 1971 | Ro:On 710915,during Monthly Surveillance Test,Eccs Pump Start Permissive Pressure Switches Tripped Below Settings Specified in Tech Specs.Caused by Incorrect Calibr Procedure.Switches Recalibr & Tested.Procedure Revised | |
ML20235E102 | 28 September 1971 | Ro:On 710918,HPCI Sys Declared Inoperable & Remained So Until 710924.Caused by Recurrent Increase in Flow Elbow Differential Pressure Leading HPCI Steam Line to Isolate. Flow Rate Testing Procedure Revised to Isolate B Steam Line | |
ML20235E256 | 5 October 1971 | Ro:On 710905,ECCS Initiation Problems Re Loss of Plant Air Noted.On 710909,false Initiation Signal Occurred During Surveillance Test & lo-lo Reactor Water Level Switch Failed. Caused by Human Error & Mechanical Failure | |
ML20235E386 | 5 November 1971 | Ro:On 711006,13 & 15,respectively, Core Spray Header Differential Pressure Switch Isolated,Steam Line Differential Pressure Switch Failed & Low Condenser Vacuum Scram Instrument Setpoint Drifted.Conditions Corrected | |
ML20235E411 | 15 December 1971 | Ro:On 711116,while Reactor Shut Down,Structural Damage to Torus Baffles Noted.Caused by Initial Transient Dynamic Loading Due to Discharge Into Torus Water.Baffles Removed & Relief Valve Discharge Lines Fitted W/Rams Head Tee | |
ML20235E564 | 28 January 1972 | Ro:On 710928,following Reactor Scram & Isolation,Safety/ Relief Valve D Failed to Seat on Manual Actuation.Caused by Galled Stem in Main Valve Piston Assembly,Leading Valve to Stick.New Discs W/Stellite Coated Stems Installed | |
ML20235E641 | 16 November 1972 | Telecopy Ro:On 721115,MSIV 1-203-2D Would Not Check Properly Using Test Circuit Load.Valve Closed to Comply W/Tech Spec Section 3.7.D.S | |
ML20235E679 | 15 February 1972 | Supplementary Ro:On 711116,structural Damage to Torus Baffles Discovered.Caused by Initial Transient Dynamic Loading.Listed Repair Work,Including Catwalk Bracing & Insps Completed.Updated Diagrams Encl | |
ML20235E790 | 21 February 1972 | Supplemental Ro:Updates Listed Util Repts Re Defective Main Steam Line High Flow Switches,Eccs Pump Start Permissive Switch (Ps) & ECCS Valve Operating Ps,Respectively. Instrumentation Problems Diagnosed & Corrected | |
ML20235E908 | 25 November 1972 | Telecopy Ro:During Routine Surveillance Calibr on Main Steam Line Flow Switches,Two Switches Found to Have Drifted Beyond Tech Spec Limit.Both Switches Recalibr | |
ML20235E968 | 2 June 1972 | Ro:On 720226,during Turbine Stop Valve 10% Closure Surveillance Test,All Stop Valves Tripped Closed Causing Reactor Scram & Momentary Opening of Safety Valve A.Caused by Loss of Turbine Trip Oil Pressure & Steam Transient | |
ML20235F038 | 28 July 1972 | Ro:On 720721,main Transformer Fire Deluge Sys Initiated by Short in Manual Initiation Circuit.Caused by Malfunction of Steamline safety-relief Valve D.Valve Replaced |