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Issue date | Title | Topic | |
---|---|---|---|
ML20086E437 | 27 June 1974 | AO 74-10:on 740626,HPCI Inverter Tripped,Rendering HPCI Sys Inoperable.Cause Not Stated.Inverter Replaced | |
ML20086E460 | 3 July 1974 | AO 74-09:in 740625,movements of LPCI Loop Break Detection Logic Differential Pressure Indicating Switches 2-129B & 2-129C Found Sticking,Causing Pointer to Log Input Pressure. Caused by Frequent Switch Actuation | |
ML20086E473 | 26 June 1974 | AO 74-09:on 740625,movements of LPCI Loop Break Detection Logic Differential Pressure Indicating Switches 2-129B & 2-129C Sluggish,Causing Pointer to Lag Input Pressure.Switch 2-129B Replaced & 2-129C Placed in Trip Condition | |
ML20086E500 | 13 June 1974 | AO 74-08:on 740525,water Discovered in Ventilation Ducting & in Instrument Penetrations at Biological Shield.Caused by Leak on Control Rod Drive Hydraulic Sys Return Line to Reactor Vessel,Due to Stress Corrosion Cracking | Hydrostatic Liquid penetrant |
ML20086E576 | 4 June 1974 | AO 74-08:detailed Rept & Analysis Including Appropriate Corrective Measures Taken Re 740526 Incident Will Be Submitted within 20 Days of Occurrence | |
ML20086E583 | 28 May 1974 | AO 74-08:on 740525,water Leakage Discovered Along Reactor Vessel Wall.Caused by Leak on Control Rod Drive Hydraulic Sys Return Line to Reactor Vessel.Engineering Review & Assessment Underway | |
ML20086E636 | 15 May 1974 | AO 74-07:on 740509,spike Observed on Plant Stack Gas Recorder,Resulting in Stack Release Peak Greater than Allowed by Tech Specs.Caused by Steam Packing Exhauster Operation | |
ML20086E639 | 10 May 1974 | AO 74-07:on 740509,spike Observed on Plant Stack Gas Recorder,Resulting in Stack Release Peak Greater than Allowed by Tech Specs.Cause Not Stated | |
ML20086E652 | 25 April 1974 | AO 74-06:on 740418,both Access Doors to North Entrance to Reactor Bldg Found Partially Open.Caused by Personnel Failing to Verify Closure.Design Adequacy Under Review | |
ML20086E664 | 19 April 1974 | AO 74-06:on 740418,both Access Doors to North Entrance to Reactor Bldg Found Open.Caused by Personnel Failure to Verify Closure.Methods to Assure Closure Underway | |
ML20086E677 | 11 March 1974 | AO 74-05:on 740304,LPCI Loop a Valve V10-25A Failed to Open When Control Switch Placed in Open Position.Caused by Burned Out Valve Motor.Motor Replaced | |
ML20086E696 | 5 March 1974 | AO 74-05:on 740304,LPCI Valve V10-25A Failed to Open When Control Switch Placed in Open Position.Caused by Tripped Motor Breaker & Unusually Warm Motor.Motor Replaced | |
ML20086E713 | 1 March 1974 | AO 74-04:on 740223,MSIV Rv 2-71B Failed to Open at Required Setpoint.Indirectly Caused by Approved vendor-recommended Mods to Certain Relief Valve Internals.Procedure Revised | |
ML20086E724 | 25 February 1974 | AO 74-04:on 740223,MSIV Rv 2-71B Failed to Open at Required Setpoint.Cause Under Investigation | |
ML20086E732 | 11 February 1974 | AO 74-03:on 740204,LPCI Differential Pressure Indicating Switch 2-137B Failed to Indicate Properly Upon Isolation from Normal Sys Pressure W/Bypass Valve Open.Caused by Improper Sensor over-range Stop Setting.Sensors Calibr | Overtravel |
ML20086E747 | 4 February 1974 | AO 74-03:on 740204,LPCI Differential Pressure Indicating Switch 2-137B Failed to Indicate Properly Upon Isolation from Normal Sys Pressure W/Bypass Valve Open.Cause Not Stated.Sensor Replaced | |
ML20086E754 | 7 February 1974 | AO 74-02:on 740131,core Spray Sys Valve CS-11A Failed to Open When Control Switch Placed in Open Position.Caused by burned-out Valve Motor.Motor Replaced | |
ML20086E763 | 1 February 1974 | AO 74-02:on 740131,core Spray Sys Valve CS-11A Failed to Open When Control Switch Placed in Open Position.Cause Not Stated.Surveillance Testing Completed & Sys Aligned to Standby Mode | |
ML20086E782 | 31 January 1974 | AO 74-01:on 740124,reactor Scrammed,Resulting from Turbine Trip Causing Automatic Closure of All But One Msiv.Valve 2-80C Failed to Close Due to Failure of Pneumatic Pilot Valve to Actuate.Valve Assembly Returned to Vendor for Insp | |
ML20086E790 | 25 January 1974 | AO 74-01:on 740124,reactor Scrammed Due to Turbine Trip, Causing Automatic Closure of All But One Msiv.Cause of Valve 2-80C Failure Not Stated | |
ML20086E813 | 26 December 1973 | AO 73-35:on 731219,MSIV Relay 5A-K3C Failed to Energize During Monthly MSIV Functional Test.Caused by Limit Switch Actuating Arm Being in Wrong Position.Arm Manually Reset | |
ML20086E826 | 20 December 1973 | AO 75-35:on 731219,MSIV Relay 5A-K3C Failed to Energize During Monthly MSIV Functional Test.Caused by Mispositioned Limit Switch Actuating Arm.Arm Manually Reset | |
ML20086E835 | 27 December 1973 | AO 73-34:on 731217,station Svc Water Pump a 4-kV Breaker Stationary Auxiliary Switch Assembly Rear Mounting Tie Bolt Found Disengaged from Mounting Plate.Caused by Improper Bolt Tightening During Factory Assembly | |
ML20086E840 | 19 December 1973 | AO 73-34:on 731217,station Svc Water Pump a 4-kV Breaker Stationary Auxiliary Switch Assembly Rear Mounting Tie Bolt Found Disengaged.Bolt Tightened | |
ML20086H166 | 26 January 1973 | AO 50-271/72-19:on 721227,internal Fault on Startup Transformer Resulted in Loss of Normal Power Onsite.Caused by Failure of Safety Valve a to Lift.Pilot Valve Internals Will Be Replaced & Replacement Transformers Installed | |
ML20086H170 | 28 December 1972 | AO 50-271/72-18:on 721222,containment Victoreen Air Monitor Pump Failed.Total RCS Leakage Ascertained Daily Until 721227.Pump Repair Completed & Sys Restored to Full Operation | |
ML20086H172 | 28 December 1972 | AO 50-271/72-17:on 721222,during Monthly HPCI Pump Surveillance Test,Gasket on Gland Seal Exhaust Condenser Failed.Caused by Overpressurization of Condenser Due to Improper Setting of HPCI PCV23-50.Valve Reset | |
ML20086H176 | 22 December 1972 | AO 50-271/72-17:on 721222,during Monthly HPCI Pump Surveillance Test,Gasket on Gland Seal Exhaust Condenser Failed.Replacement of Gasket Initiated & Cooler Repaired | |
ML20086H181 | 21 December 1972 | AO 50-271/72-15:on 721219,during HPCI Sys Surveillance,Hpci Steam Line High Differential Pressure Switch DPIS 23-77 Tripped at 200 Inches of Water.Sensor Immediately Reset & Verified | |
ML20086H186 | 20 December 1972 | AO 50-271/72-15:on 721219,HPCI Steamline High Differential Pressure Switch DPS 23-77 Tripped at 200 Inches of Water. Sensor Immediately Reset & Verified within Limits | |
ML20086H190 | 4 December 1972 | AO 50-271/72-14:on 821204,during Core Spray Sys Surveillance,Reactor Pressure Switch Ps 2-3-52B Actuated at Less than 335 Psig.Switch Immediately Reset & Verified | |
ML20086H212 | 10 November 1972 | AO 50-271/72-13:on 721109,during Sampling of Outside Radwaste Tanks,Total Activity of Tanks Found to Be 7.296 Ci, Exceeding Tech Spec Limit of 0.3 Ci.Caused by High Xenon Content in Water.Tanks Recycled & Restored on 721110 | |
ML20086H222 | 8 November 1972 | AO 50-271/72-10:on 721101,scram Discharge Vol High Water Level Switch Lsh 3-231C Failed to Actuate at Tech Spec Limit of 24 Gallons.Caused by Initial Corrosion within Sys.Float Chamber Flushed & Switch Verified | |
ML20086H225 | 2 November 1972 | AO 50-271/72-10:on 721101,scram Discharge Vol High Water Level Switch Lsh 3-231C Failed to Actuate on High Water Level.Switch Chamber Immediately Cleaned & Flushed & Switch Verified | |
ML20086H228 | 7 November 1972 | AO 50-271/72-12:on 721106,offgas Sample Chamber Isolated Intentionally to Permit Replacement of Chamber Flow Metering Valve.Valve Found Leaking.Valve Replaced & Three Fittings & One Union Tightened | |
ML20086H246 | 1 November 1972 | AO 50-271/72-09:on 721026,two Barton Steam Line Differential Pressure Switches (DPIS 13-83 & 13-84) Failed to Actuate at Required Pressure of 180 Inches.Locking Devices May Be Causing Change.Switches Immediately Reset | |
ML20086H250 | 27 October 1972 | AO 50-271/72-09:on 721026,two Barton Steam Line Differential Pressure Switches (DPIS 13-83 & 13-84) Actuated at 195 Inches,Exceeding Tech Spec Limit of 180 Inches.Switches Immediately Reset | |
ML20086H255 | 25 August 1972 | AO 50-271/72-02:on 720801-08,airborne Contamination Levels within Containment Exceeded Average Level.Reactor Containment Required Due to Investigation of All Drywell Pressure Penetration taps.Open-ended Tees Plugged | |
ML20086H270 | 26 October 1972 | AO 50-271/72-08:on 721020,during Automatic Depressurization Sys B Logic Test,Relief Valve Initiation Time Delay Relay 2E-K5B Failed to Energize in 120 S.Relay Immediately Reset | |
ML20086H275 | 20 October 1972 | AO 50-271/72-08:on 731020,during Automatic Depressurization Sys B Logic Test,Relief Valve Initiation Time Delay Relay 2E-K5B Energized at 123 S,Exceeding Tech Spec Limit of 120 S.Relay Immediately Reset | |
ML20086H288 | 3 October 1972 | AO 50-271/72-06:on 720928,steam Line High Differential Pressure Switch DPIS 13-84 Failed to Operate at Required 180 Inches of Water.Caused by Broken Common Lead.Lead Repaired | |
ML20086H295 | 29 September 1972 | AO 50-271/72-06:on 720928,one Channel of Steam Line High D/P Isolation Failed to Operate at 180 Inches of Water.Caused by Broken Common Lead Between Conduit Fitting & Switch Terminal Board.Lead Repaired | |
ML20086H300 | 29 September 1972 | Ao:On 720904,two Solenoid Operated Isolatation Valves in Torus Sampling Connection Found Not to Close on Isolation Signal.Caused by Valve Piston Binding.Piston Rings Removed, Valves Cleaned & Reassembled | |
ML20086H303 | 17 August 1972 | AO 50-271/72-02:on 720801-08,during Investigation of All Drywell Pressure Penetration Caps,Reactor Coolant Temp Exceeded Tech Spec Limit.Caused by open-ended Tees.Tees in Sensing Lines Plugged | |
ML20086H307 | 26 September 1972 | Ao:On 720803,RCIC Sys Turbine Steam Admission Valve RCIC-131 Failed.Caused by Piece of Metal Lodged on Valve Seat & Burned Out Motor.Metal Removed & Motor Replaced | |
ML20086H309 | 22 September 1972 | AO 50-271/72-05:on 720921,supply Valve to Offgas Sample Chamber Closed.Caused by Inadvertent Shutting of Valve During Initial Operation of Air Ejector Sys.Procedures Revised to Assign locked-open Valves | Time of Discovery Grab sample |
ML20086H321 | 19 October 1972 | AO 50-271/72-07:on 721010,alarm Annunicated in Main Control Room Indicating Leak in Bellows Assembly of Main Steam Relief Valve D.Caused by Residual Moisture Trapped in Tubing.Tubing Drained & Vented | |
ML20086H324 | 11 October 1972 | AO 50-271/72-07:on 721010,alarm Annunciated in Main Control Room,Indicating Leak in Bellows Assembly of Main Steam Relief Valve D.Vendor Evaluating Problem | |
ML20086H336 | 27 September 1972 | AO 50-271/72-04:on 720919,alarm Annunciated in Main Control Room Indicating Leak in Bellows of Main Steam Relief Valve. Failure Could Render One Relief Valve Incapable of Relieving Steam Pressure at Tech Spec Setpoint | |
ML20086H343 | 22 September 1972 | AO 50-271/72-05:on 720921,supply Valve to Offgas Sample Chamber Found Closed.Offgas Activity Measured at 5 Mrm/Hr & Grab Sample of Air Ejectors Showed 145 Uci/S.Review Being Conducted | Grab sample |