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| Issue date | Title | Topic | |
|---|---|---|---|
| ML20151W232 | 8 September 1998 | Ro:On 980826,facility Bldg Air Monitor (Fam Channel 4) Failed Daily Fam Alarm Checks Prior to Reactor Operation. Caused by Failed Alarm Relay.Staff Is Preparing Formal Written Procedures for Testing Configurations for Fam Sys | |
| ML20217A089 | 18 March 1998 | Ro:On 980218,potential Reactor Safety Failure Discovered W/ Reactor Shutdown.Caused by Manual Scram Function Bypassed by Sticking Reset Contact in Console Power key-switch. Protective Action Reset Switches Wired | |
| ML20199C537 | 11 November 1997 | Ro:On 971030,shim Safety Number 2 Was Found to Be Binding & Became Stuck in Withdrawn Position & Control Rod Failed to Scram.Caused by Incorrect Spacing Between Hold Down Foot & Bundle top-handle.Procedure SOP-II-I Modified | |
| ML20129H519 | 30 October 1996 | Ro:On 961015,loss of Facility Power Occurred Causing Reactor Scram Due to Lack of Attention to Detail & Excessive Distractions to Operations.Startup Checklist Had Several Individual Instrument Checks Combined Into Single Items | |
| ML20079C248 | 10 June 1991 | Ro:On 910607,reactor Operated for 30 Minutes at 1 MW W/O Facility Air Monitors in Operation.Operator Removed from Watch Standing Duties.Final Rept Will Be Forwarded Upon Completion | |
| ML20066H140 | 8 February 1991 | Special Rept 90-01:on 910125,during Annual Fuel Insp of Operational Core VIII-A,fuel Elements 6502 & 8468 Failed to Pass go-no-go Gauge Test for Excessive Transverse Bend. Elements Replaced W/Spare & Fuel Bundles Relocated | |
| ML20203G787 | 22 July 1986 | RO 86-03:on 860508,no Down Signal Received from Transient Rod During Manual Scram.Caused by Fine Grit in Air Cylinder Causing Friction & Preventing Full Insertion.Cylinder Cleaned & Lubricated & Air Filter Replaced | Shutdown Margin |
| ML20203B009 | 10 July 1986 | Ro:On 860708,no Rod Down Indication Received for Transient Rod Until Carriage Driven In,During Performance of Manual Scram for Reactor Shutdown.Caused by Malfunction of Reactor Safety Sys Component.Repairs Underway | |
| ML20199B117 | 4 June 1986 | Ro:On 860501,improper Handling of Experiment Discovered Which Could Have Resulted in Serious Operational Event. Caused by Insertion of $1.09 Reactivity.Postulated Accidents & Results & Related Info Encl | |
| ML20205Q292 | 16 May 1986 | Final Ro:On 860501,unanticipated or Uncontrolled Change in Reactivity Greater than One Dollar Occurred.Caused by Removal of Rotisserie from Face Water Notch.Proposed Changes to SOPs Developed as Listed | |
| ML20205J931 | 18 February 1986 | RO 86-01:on 860204,temp Recorder Providing LSSS Signal to Scram on High Fuel Temp Malfunctioned.Caused by Defective Motor Bearing.Bearing Replaced & Recorder Calibr | |
| ML20137Y629 | 24 September 1985 | RO-85-04:on 850912,transient Rod Followed Cylinder Out During Positioning of Transient Rod Cylinder.Air Solenoid for Transient Rod Sys Not Functioning as Designed.Air Solenoid Disassembled,Cleaned & Reassembled | |
| ML20127M415 | 9 May 1985 | Ro:On 850508,during Restart Following Power Failure,Facility Air Monitoring (Fam) Sys Inoperable for 15 Minutes.Caused by Turning Off High Voltage to Detectors.Procedures Revised to Verify Fam Sys After Power Failure | |
| ML20113D568 | 21 January 1985 | RO 85-2;on 850111,safety Channel 1 Detector Failed During Reactor Operation.Caused by Loose Connector Pin Making Intermittent Contact.New Connector Installed & Detector Verified Operable Prior to Reinstallation | |
| ML20134Q196 | 11 January 1985 | Ro:On 850111,reactor Shut Down When Safety Channel 1 Did Not Respond Following Annual Reactor Maint.Cause Undetermined. Detector & Cabling Replaced | |
| ML20134P739 | 10 January 1985 | RO 85-1:on 850108,fuel Temp Recorder Indicated 600 F Instead of 720 F.Caused by Failure of Reactor Safety Sys Channel. Faulty Slide Wire & Contact Arm Replaced | |
| ML20134Q208 | 8 January 1985 | Ro:On 850108,fuel Temp Recorder Indicated 600 F Instead of 720 F After Reactor Power Returned to 1 MW Following Sample Positioning.Reactor Shut Down & Faulty Slide Wire & Contact Arm Replaced | |
| ML20090E125 | 2 July 1984 | RO-84-4:on 840626,reactor Operator Noted That Fuel Element Temp Recorder Did Not Correspond to Digital Indication as Shown on Doric Temp Readout.Cause Not Stated.Failure Spurious & Could Not Be Reproduced | |
| ML20090D784 | 26 June 1984 | Telecopy Ro:On 840626,fuel Elements Temp Recorder Failed to Respond Following Temporary Reduction in Reactor Power.Cause Not Stated | |
| ML20090E124 | 15 June 1984 | RO 84-3:on 840604,reactor Operator Observed That Safety Power Measuring Channel 2 Not Responding as Reactor Power Level Increased Beyond 30 Kw.Caused by Loose Safety Channel 2 Signal Cable.Connector Replaced | |
| ML20090E514 | 11 June 1984 | RO 84-2:on 840528,erratic Performance of Reactor Servo Control Not Noted in Log.Caused by Personnel Error.Operator Cautioned to Be More Observant While Taking Log Readings | |
| ML20134Q251 | 5 June 1984 | Ro:On 840604,during Startup,Reactor Shut Down When Channel 2 Not Indicating in Expected Power Range.Caused by Faulty Connector.Faulty Signal Cable Connector Replaced & Normal Operations Resumed | |
| ML20092N921 | 29 May 1984 | Ro:On 840528,operator Received Servo Fault Alarm & Linear Power Channel Indication Failed Low.Caused by High Voltage Supply for Linear Defector de-energized | |
| ML20084H617 | 2 April 1984 | Ro:On 840319,discovered That Performance of Weekly Electronic Maint Checks Not Performed During Previous Wk of Operation.Caused by Inadequate Procedural Controls | |
| ML20078P011 | 28 October 1983 | Ro:On 831004,high Power Scram Received During Initial Reactor Startup While Banking Shim Safety Control Rods After Reaching 1 MW Power.Caused by Operator Manipulation of Control Rods.Procedures & Proper Documentation Emphasized | |
| ML20070M810 | 11 January 1983 | Ro:On 830105,during Fuel Element Insp,Elements 7463 & 7486 Failed Go/No Go Test.Both Elements Had Been in Core Since 1973 & Not Inspected Since That Time.Both Elements Removed from Core | Time of Discovery |
| ML20070N647 | 11 January 1983 | Ro:On 830110,fuel Temp Indication Failed to Respond During Reactor Startup.Caused by Shorted Thermocouple Wires in Terminal Box.Reactor Shut Down & Fuel Temp Instrument Connected to More Conservative Indication | |
| ML20072A823 | 22 December 1982 | Ro:On 821204,power Calorimetric Performed to Determine Agreement Between Indicated Power & Calculated Actual Power Based on Pool Heatup Rate.Results Showed Minus 30.7% Error. on 821206,calorimetric Showed Plus 56.6% Error | |
| ML20070M776 | 20 December 1982 | Telecopy of Ro:On 821204,following Core Change,Power Calorimetric Indicated Power 30% Low.Detectors Adjusted. After Series of Addl Calorimeter Performances,Results Indicated Facility Could Operate in Excess of 35% Power | |
| ML20067C972 | 29 October 1982 | Ro:On 821019,power Level Indication Dropped Approx 15% on Both Safety Channels.On 821027,electromagnet Current for Shim Safety 2 Went to Zero.Causes Not Stated.Electromagnet Coil Replaced | |
| ML20066A573 | 5 October 1982 | Ro:On 820928,during Operation,Fuel Temp Thermocouple Failed. New Instrumented Fuel Element Installed.Thermocouple Readings Normal | |
| ML20066A249 | 29 September 1982 | Telecopy Ro:On 820928,erratic Readings Noted on Fuel Temp Indicator.Reactor Shut Down Immediately.On 820929,different If Connected to Fuel Temp Channel & Thermocouple Readings Recorded at 300 Watts & 1 MW | |
| ML20063H030 | 22 July 1982 | Telecopy Message of Ro:On 820722,during Initial & Secondary Reactor Startup,Log Power Channel Rate Meter Failed to Respond.Cleaning of Switch Contacts Returned Instrument to Normal Operation | |
| ML20063H073 | 22 July 1982 | Ro:On 820722,during Initial Startup,Log Power Channel Rate Meter Failed to Respond.Cause Not Stated.Switch Contacts & Amplifier Boards Cleaned.Close Visual Insps Implemented | |
| ML20126L448 | 15 April 1981 | Ro:On 810409 & 0414,during Prestartup Check of Facility, Interlock to Prevent Withdrawal of Shim Safety Control Rods for Low Source Levels Was Not Functioning.Caused by Defective Relay.Relay Replaced Prior to Reactor Operations |