Semantic search

Jump to navigation Jump to search
 Issue dateTitleTopic
ML20083Q03917 January 1973Ao:On 721229,electromatic Relief Valve Failed to Reset Causing Primary Sys Blowdown Following Reactor Scram.As Result,Three Different Valves Failed to Operate in Intended Manner.Manufacturers & Valve Users Will Be ConsultedBreakaway torque
ML20084A09029 October 1973Ao:On 730915,following Investigation of Excess Letdown Line Leak,Valve 1MOV-1299 Downstream Seat Protruded from Valve Body & Crack Discovered in Upper Portion of Downstream Seat Ring.Cause Unknown.Vendor Notified of Valve Problem
ML20084B71226 June 1972Ao:On 720524,essential Svc Motor Generator Set Failed Resulting in Feedwater Control Sys Failure & Reactor Scram. Caused by Dirty Contacts on 2K Relay.Hfa Relay Replaced
ML20084C5574 October 1974AO 50-219/74-48:on 740925,isolation Condensers a & B Inoperable Due to High Flow as Sensed by Condensate Line Break Sensors.Caused by Tripping of Line Break Sensors Due to Effects of Rated Recirculation Flow
ML20084C58030 September 1974Preliminary AO 50-219/74-48:on 740927,main Steam Line Low Pressure Switch RE23A Found to Trip at Pressure Less than Min of 860 Psig.Caused by Switch Repeatability.Ge Submitted Info to Reduce SetpointFuel cladding
ML20084C78626 August 1974Preliminary AO 50-219/74/45:on 740824,commitment to Follow MAPLHGR Limits Violated.Caused by Insufficient Guidance. Reactor Power Reduced by Recirculation Flow to Point Where No MAPLHGR Limits Violated
ML20084D23912 April 1974Preliminary AO 50-219/74/26:on 740412,emergency Svc Water Pump 52C Failed to Start.Cause Under Investigation
ML20084E8515 October 1970Telecopy Ao:On 701004,gape Valve 852B Only Opened Halfway. Caused by Loose Stem Nut of Limitorque Operator.Nut Replaced
ML20084E86314 October 1970Telecopy Message of Ao:On 701014,gate Valve 851A Failed to Fully Close.Caused by Loose Stem Nut Locking.Lock Tightened & Stem Lubricated
ML20084T88215 June 1970Ao:On 700605,turbine electro-hydraulic Control Sys Transient Caused Turbine Trip & Reactor Scram,Followed by Inadvertently Opened Safety Valves.Two Safety Valves Failed to Close,Releasing Primary Coolant to Containment
ML20084U9502 January 1975AO 50-265/74-29:on 741223,cracks at Welds in 4 Inch Reactor Recirculation Discharge Valve Bypass Lines Indicated.Cause Undetermined.Piping on a & B Loops to Be Completely Replaced
ML20084U95623 December 1974Telecopy Ao:Three Weld Abnormalities Discovered on Welds in Bypass Piping Lines Around Recirculation Pump Discharge Valves.Plans Formulated to Replace Lines
ML20085E9559 July 1975AO 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
ML20085G18624 October 1973Ao:On 730925,trip Setpoint of 152 Inches for HPCI Flow Switch DPIS 3-2353 Exceeded Tech Spec Limit.Caused by Locking Device Failing to Control Setpoint Drift.Switch Setpoint Changed & Calibr Frequency Increased
ML20085G18826 October 1973AO BFAO-7327W:on 731016,setpoint of 1.8 Psid for Recirculation Jet Pump Riser Differential Pressure Switch PdIS-68-24 Exceeded Tech Spec Limit.Switch Recalibr,Tested & Frequency Increased to Once Every 2 Wks
ML20085G82318 September 1973AO BFAO-739W:on 730908,fuse Blew in Power Supplying HPCI Inverter Power Supply.Caused by Generic Problem W/Inverter. Fuse Replaced & Manufacturer Making Changes to Inverter Model
ML20085K06020 December 1973Ao:On 731212,w/reactor at Full Temp & Pressure,Mechanical Failure of Oil Line in HPCI Turbine Control Sys Rendered Turbine Operable.Caused by Full Circumferential Sheer Failure of Pipe Bushing.Bushing Replaced
ML20085K07025 January 1974Ao:On 740117,during Operability Test on Hpci,Sys Revealed to Be Inoperable.Caused by Burrs on Cylinder Wall & Piston of Turbine Stop Valve.Burrs Removed & All Parts Thoroughly Cleaned & Inspected
ML20085M75123 November 1973AO BFAO-7338W:on 731115,at 25% Power W/Msiv Closed,Rcic & HPCI Sys Failed.Caused by Movable Contact of Dc Contactor Being Hung in Arcing Horn.Contactor RepairedSafe Shutdown
Reactor Vessel Water Level
ML20086D3172 September 1975AO 75-018:on 750901,steam Supply Valve 13-15 Failed to Close When Control Switch Placed in Closed Position.After Repeated Attempts,Valve 13-15 Responded & Cycled Closed.Valve Stroked,Timed to Ensure Operability & Declared Inoperable
ML20086D36725 July 1975Telecopy AO 75-014:on 750725,head Gasket on Gland Seal Exhaust Condenser Failed.Replacement of Failed Gasket Initiated Immediately.Condenser Repaired & HPCI Sys Tested & Verified Operable
ML20086D3758 July 1975Telecopy AO 75-013:on 750707,injection Valve CS-11B Failed to Open When Control Switch Placed in Open Position.Valve Immediately Opened Manually to Full Open Position.Sys Aligned to Normal Standby Mode
ML20086D59028 December 1972AO 72-16:on 721227,startup Transformer Failed,Resulting in Loss of Normal Power.Incident Under Investigation. Replacement Startup Transformer Procured & Will Be Installed in Near Future
ML20086D59328 December 1972Final AO 72-16:on 721220,fan 1 on West Cooling Tower Tripped.Caused by Failure of Motor Overload Heater.Overload Heater Replaced & Fan Returned to Svc
ML20086D59621 December 1972AO 72-16:on 721220,fan 1 on West Cooling Tower Tripped. Initial Investigation Showed Main Contactor Failed.Repair & Return to Normal Operation of Fan Will Be Complete Prior to 721227
ML20086D6035 December 1973AO 73-33:on 731204,pressure Switch Ps 14-44B Failed to Actuate at Required Setpoint,Resulting in Failure of B Core Spray Subsystem.Switch Reset & B Core Spray Subsystem Declared Operable
ML20086D6113 July 1973Updated AO 73-19:on 730625,during RCIC Surveillance Testing to Check Auto Closure of RCIC Steam Isolation Valves 15 & 16,valve 15 Failed to Close as Required.Caused by Misalignment or Binding in Declutch Mechanism
ML20086D61512 December 1973Updated AO 73-33:on 731204,pressure Switch Ps 14-44B Failed to Actuate at Required Setpoint,Resulting in Failure of B Core Spray Subsystem.Caused by Setpoint Drift.Switch Reset & B Core Spray Subsystem Declared Operable
ML20086D62025 June 1973AO 73-19:on 730625,during RCIC Surveillance Testing to Check Auto Closure of RCIC Steam Isolation Valves 15 & 16,valve 15 Failed to Close as Required.Several Attempts Made to Close Valve Remotely from Control Room Panel W/No Success
ML20086D62320 November 1973AO 73-32:on 731120,during Monthly HPCI Sys Pump Operability Surveillance Test,Both Gaskets on Gland Seal Exhaust Condenser Failed.Cooler Repaired & HPCI Tested & Verified Operable
ML20086D62728 November 1973Updated AO 73-32:on 731120,during Monthly HPCI Sys Pump Operability Surveillance Test,Both Gaskets on Gland Seal Exhaust Condenser Failed.Caused by Overpressurization of Condenser.Cooler Repaired & HPCI Verified Operable
ML20086D6323 July 1973AO 73-18:on 730625,Barton Differential Pressure Switch Sensing RCIC Steam Line High Differential Pressure Actuated Below 150 Inches of Water.Switch Immediately Reset, Functionally Tested Ten Times & Verified within Tolerance
ML20086D64925 June 1973AO 73-18:on 730625,Barton Differential Pressure Switch Sensing RCIC Steam Line High Differential Pressure Actuated Below 150 Inches of Water.Switch Immediately Reset, Functionally Tested 10 Times & Verified within Tolerance
ML20086D65621 June 1973Updated AO 73-17:on 730614,drywell Purge & Vent Exhaust Valve V-16-19-7A Failed to Shut.Valves V-16-19-4 & V-16-19-16 Closed,Insuring Containment Integrity.Valve Will Remain Shut Until Primary Integrity Not Required
ML20086D67114 June 1973AO 73-17:on 730614,drywell Purging & Vent Exhaust Valve V-16-19-7A Failed to Shut.Valves V-16-19-4 & V-16-19-16 Closed Immediately,Insuring Containment Integrity.Valve V-16-19-7A Subsequently Shut & Air Operator Secured
ML20086D68622 June 1973AO 73-16:on 730612,during Severe Electrical Storm in Which Direct Lightning Strike to Top of Plant Ventilation Stack Observed,Detonation in Offgas Sys Caused Sufficient Back Pressure to Fracture Air Ejector Rupture Disc
ML20086D69213 June 1973AO 73-16:on 730612,during Severe Electrical Storm in Which Direct Lightning Strike to Top of Plant Ventilation Stack Observed,Detonation in Offgas Sys Caused Sufficient Back Pressure to Fracture Air Rejector Rupture Disc
ML20086D70821 June 1973Updated AO 73-15:on 730612,first-stage Turbine Pressure Permissive Pressure Switch 5-14A Failed to Actuate at Proper Setpoint.Switch Reset.Surveillance Test Will Be Conducted Again in 3 Months Rather than 6 Months
ML20086D72212 June 1973AO 73-15:on 730612,first-stage Turbine Pressure Permissive Pressure Switch 5-14A Failed to Meet Proper Setpoint.Switch Reset & Returned to Svc
ML20086D7346 June 1973Updated AO 73-14:on 730530,fuse Which Supplies Ac to Main Steam Line Radiation Monitor Drawer 17-251D & High Voltage Power Supply for Reactor Bldg Ventilation Area Monitors Blew.Blown Fuse Replaced & Isolation Cleared
ML20086D73914 November 1973Updated AO 73-31:on 731107,reactor Scram Occurred,Initiated by high-high Flux Signal from Intermediate Range Neutron Monitoring Sys.Rod 30-23 Fully Withdrawn & Rod 26-23 Being Withdrawn for Friction Test
ML20086D74330 May 1973AO 73-14:on 730530,fuse Which Supplies Ac to Main Steam Line Radiation Monitor Drawer 17-251D & High Voltage Power Supply 17-451B for Reactor Bldg Ventilation Area Radiation Monitors Blew.Blown Fuse Replaced & Isolation Cleared
ML20086D74931 May 1973AO 73-13:on 730523,RHR Svc Water Pump a Failed to Shut Down from Crp 9-3 During Surveillance Testing.Mechanical Trip Mechanism in Breaker Undependable Due to Misalignment of Mechanism & High Resistance Breaker Contact
ML20086D75114 May 1973AO 73-12:on 730507:valve RHR-25A Failed to Open When Control Switch Placed in Open Position.Valve Manually Opened to Mid Position.Motor on RHR-25A Replaced & Valve Operability Demonstrated
ML20086D75520 April 1973Updated AO 73-10:on 730417,relief Valve Initiation Time Delay Relay Failed to Actuate.Similar Event Occurred on 721020.Relay Replaced & Replacement Verified.No Further Action Necessary
ML20086D76518 April 1973AO 73-10:on 730417,relief Valve Initiation Time Delay Relay Failed to Actuate.Similar Event Occurred on 721020.Relay Replaced & Replacement Verified
ML20086D76913 April 1973Updated AO 73-09:on 730410,microswitch Installed in DPIS-129B Failed to Actuate at Required Setpoint.Defective Switch Replaced,Actuating Arm Realigned & Trip Point Actuation Rechecked Repeatedly
ML20086D77510 April 1973AO 73-09:on 730410,microswitch Installed in DPIS-129B Failed to Actuate at Required Setpoint.Defective Switch Replaced, Actuating Arm Realigned & Trip Point Actuation Rechecked Repeatedly
ML20086D7848 March 1973Updated AO 73-08:on 730307,time Delay Relay Failed to Actuate Isolation of Sys within Specified Time.Check of Timer Will Be Conducted After 3 Months to Confirm Reliability of Timer.Relay Replaced & Bench Tested
ML20086D7928 March 1973AO 73-08:on 730307,time Delay Relay Failed to Actuate Isolation of Sys within Specified Time.Relay Replaced & Tested
Retrieved from "https://kanterella.com/Special:Ask"