Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20046C3131993-07-28028 July 1993 LER 93-015-00:on 930630,HPCI Sys Declared Inoperable Due to Indicated Flow During Surveillance.Caused by Foreign Matl That Plugged Portion of Restricting Orifice.Restricting Orifice Removed,Cleaned & reinstalled.W/930728 Ltr ML20045E2301993-06-25025 June 1993 LER 93-013-00:on 930530,RCIC Sys Declared Inoperable & 7 Day TS 3.5.D.2 LCO Entered Due to Speed Oscillations Which Occurred After Several Minutes of steady-state Operation. Caused by Actuator Failure.Actuator replaced.W/930625 Ltr ML20045D1861993-06-18018 June 1993 LER 93-010-00:on 930519,SUT Became de-energized During Planned Calibr of Turbine/Generator Relays Lockout Test While Shut Down.Caused by Personnel Error.Discussion Conducted W/Personnel Re Attention to detail.W/930618 Ltr ML20044H0441993-06-0202 June 1993 LER 93-009-00:on 930504,circuit Breaker Did Not Close During Planned Bus Transfer Due to Loose Control Circuit Wire.Lug Replaced & Reterminated on 930505 & Post Work Testing Completed W/Satisfactory results.W/930602 Ltr ML20012F5751990-04-0606 April 1990 LER 90-003-00:on 900311,automatic Actuation of Main Steam Sys Group 1 Portion of Primary Containment Isolation Control Sys Occurred.Caused by False High Reactor Vessel Water Level Signal.Procedure Developed Re backfill.W/900406 Ltr ML20012E9831990-03-30030 March 1990 LER 90-002-00:on 900228,determined That Max Fraction of Limiting Power Density Not Checked Daily During Reactor Power Operation,Per Tech Spec 4.1.B.On 900323,addl Tech Spec Issue Discovered.Tech Specs changed.W/900330 Ltr ML20011D1361989-12-11011 December 1989 LER 89-035-00:on 891111,inadvertent Actuation of Portion of Secondary Containment Sys During Surveillance Testing Occurred.Caused by Location of Radiation Isolation Control Sys Channel a Logic Relay.Procedure revised.W/891211 Ltr ML20005D7421989-12-0606 December 1989 LER 89-033-00:on 891106,automatic Actuation of Group 1 Portion of Primary Containment Isolation Control Sys (PCIS) Occurred.Caused by High Reactor Vessel Water Level.Manual Valve Closed & PCIS Logic Circuitry reset.W/891206 Ltr ML19332D1421989-11-22022 November 1989 LER 89-031-00:on 891024,closing Times for Two in-series Primary Containment Isolation Valves Exceeded Acceptance Criteria During Shutdown Testing.Cause Undetermined.Closing Time Retested W/Satisfactory results.W/891122 Ltr ML19332D6231989-11-20020 November 1989 LER 89-032-00:on 891020,pneumatic Pressure Drop for Two of Four Automatic Depressurization Sys Accumulators Discovered Greater than Max Acceptable Value.Caused by Leakage from Seat of Supply Check Valves.Seat replaced.W/891120 Ltr ML19324C3181989-11-0909 November 1989 LER 88-002-01:on 880117,full Reactor Protection Sys Scram Trip Signal Occurred During Surveillance Test,Resulting in Incomplete Actuations.Caused by Procedure Inadequacy.Logic Relay Replaced & Procedure revised.W/891109 Ltr ML19324B1131989-10-21021 October 1989 LER 89-030-00:on 890926,control Room High Efficiency Air Filtration Sys Flowrate non-conservative Due to Procedure Error.Caused by Transcription Error.Procedure Revised & Test Reperformed Using Corrected procedure.W/891021 Ltr ML19325D4681989-10-16016 October 1989 LER 89-029-00:on 890914,locked High Radiation Area Door Found to Have Been Unsecured Contrary to Tech Spec 6.13.2. Caused by Failure to Adhere to Approved Procedures. Training on Access Requirements initiated.W/891016 Ltr ML19325D1861989-10-10010 October 1989 LER 89-028-00:on 890907,HPCI Sys Declared Inoperable Because Mechanical Overspeed Trip Occurred During Surveillance Test. Caused by Failure of Ramp Generator Signal Converter Module. Module Removed & Sent to Mfg for exam.W/891010 Ltr ML17277B8221984-07-20020 July 1984 LER 82-049/01X-1:on 821102,main Steam Line Safety Valve a Set W/Nitrogen at Steam Relief Setting.Caused by Personnel Error.Valve Removed & Replaced W/Properly Set Spare Valve. Procedure revised.W/840720 Ltr ML20024C3231983-06-24024 June 1983 Updated LER 82-038/03X-1:on 820817,RCIC Steam Line High Differential Pressure Alarm Received.Caused by Air in Sensing Lines to Pressure Switches.Cross Threaded Cap Found on in-line Snubber.Snubber replaced.W/830624 Ltr ML20023D0181983-05-0404 May 1983 LER 83-022/03L-0:on 830413,overload on Valve Motor 1301-17 Resulted in Loss of High Pressure Core Cooling Backup Capability.Caused by Oxidation in Motor End Bell & Motor Brushes,Due to Humidity Caused by Leaking Valve Packing ML20027C9801982-10-20020 October 1982 LER 82-039/03L-0:on 820920,timing Tests of Three Reactor Water Cleanup Isolation Valves 1201-2,-5 & -80 Not Completed within Allowed Time.Caused by Operational Constraints Requiring Testing at Reduced Power ML20042A7461982-03-12012 March 1982 LER 82-005/01T-0:on 820226,deficiencies in Pipe Supports in Control Rod Driveline Insert & Withdraw Lines Identified. Caused by Missing or Loose Clamps.Restoration to Acceptable Limits Will Be Completed Before End of Cycle VI ML20041F1901982-03-0202 March 1982 LER 82-003/99L-0:on 820201,util Changed Corporate Organization.Senior vice-president Elected & vice-president & Director of Operations Review Created.Change Prompted by Need to Incorporate Oversight of safety-related Activities ML20052G0581982-02-27027 February 1982 LER 82-005/01X-0:on 820226,station Informed That Max Stresses Above Acceptable Limits in Piping Supports of Control Rod Drive Insert & Withdrawal Lines.Caused by Imcomplete Const.Restoration Will Be Completed ML20049H7761982-02-16016 February 1982 LER 82-002/03L-0:on 820118,sensing Line to Pressure Switch Found Frozen.Line Froze Again on 820119.On 820123,fire Pump Found Out of Calibr.Caused by Subzero Weather Which Reduced Effectiveness of Heating Sys.Priority Maint Requests Issued ML20041A1491982-02-0404 February 1982 LER 82-001/03L-0:on 820105,during Refueling Outage,Sliding Fire Door Found Nonfunctional During Fire Insp.Caused by Metal Channel Hindering Door Movement.All Personnel Apprised of Procedural Responsibilities ML20040F3211982-01-26026 January 1982 LER 81-065/03L-0:on 811230,during Investigation of Failure of MSIV AO-203-2A,discovered Two hold-down Bolts on Poppet W/O Lock Plates.Caused by Failure to Follow Procedures During Previous Valve Overhaul ML20039B0711981-12-0909 December 1981 LER 81-063/04T-0:on 811130,Yankee Atomic Environ Lab Rept Received Indicating Reportable Concentration of Cs-137 in Cranberry Sample from Manomet Point Bog.Apparently Caused by Previous Weapons Testing & Inadequate Potassium in Soil ML20049A8191981-09-22022 September 1981 LER 81-047/03L-0:on 810824,during Surveillance Test,One Channel of Rod Block Monitor Found to Be Not Functional. Caused by Failed Zener Diode on Flow Control Trip Ref Unit. Unit Replaced ML19350F0071981-06-16016 June 1981 Updated LER 81-018/03X-1:on 810512,stack Gas Radiation Monitor 1705-18A Was Downscale & Inoperable Following Lightning Strike Near Main Stack.Caused by Voltage Surge Resulting in Preamplifier & Discriminator Circuits Failure ML19350E2831981-06-10010 June 1981 LER 81-019/03L-0:on 810514,level Recorder 5049 Was Found Indicating High.Caused by Calibr Shift Due to Jarring Instrument Sensing Lines During Installation of Torus Room Staging.Recorder & Transmitters Recalibr ML19352B2021981-05-28028 May 1981 LER 81-016/03L-0:on 810430,reactor Core Isolation Cooling Valve Mo 1301-17 Failed to Close on Demand Following Switch Actuation.Caused by Deteriorated Packing Jammed Between Valve Stem & Packing Gland.Packing Replaced ML20004D7451981-05-18018 May 1981 Updated LER 80-058/03L-1:on 800821,while Conducting HPCI Sys Test,Hpci Sys Declared Inoperable.Possibly Caused by Dirt Which Caused Temporary Malfunction of Turbine Throttle Valve.Tests by Factory Representative Satisfactory ML20003D5371981-03-19019 March 1981 LER 81-007/03L-0:on 810217,reactor Coolant Leak Detection Air Sampling Sys Declared Inoperable.Caused by Blown Fuses. Fuses Replaced.Pump Will Be Rebuilt ML19350B5141981-03-10010 March 1981 LER 81-004/01T-0:on 810225,review Indicated That If Backup Scram Solenoids Failed,Actuation of ATWS Sys Would Prevent Closure of Scram Discharge Vol Vent & Drain Valves,Violating Primary Containment.Cause Due to Oversight in Design ML20003C6741981-03-0202 March 1981 LER 81-005/03L-0:on 810202,unidentified Reactor Drywell Coolant Leakage Rates Measured Above Tech Spec Level.Cause Not Stated.Recirculation Pump Suction Valves a & B & Discharge Valves Backseated ML20003B2571981-02-0606 February 1981 LER 81-002/03L-0:on 810107,main Stack Sample Flow Alarm Received Twice on Panel C903 in Control Room.Caused by Frozen Suction Line (First Occurrence) & Blown Power Supply Fuse (Second Occurrence) ML19345E1581980-12-17017 December 1980 LER 80-089/03L-0:on 801117,torus Water Level Indicator Lr 5038 on Panel C903 in Control Room Began to Oscillate Irradically.Instrument Declared Inoperable.Caused by Failure of Forced Balanced Motor Boyancy Level Transmitter ML19351E6561980-11-28028 November 1980 LER 80-084/01X-1:on 801113,water Leak Discovered from 2- Inch Reactor Vessel Drain Line.Caused by Faulty Weld.Weld Isolated & Ground Out.Coupling Rewelded ML19345B8581980-11-28028 November 1980 LER 80-084/01X-0:on 801113,leak Discovered in 2-inch Reactor Vessel Drain Line Connected to Reactor Water Cleanup Sys. Caused by Slag Inclusions in Pipe Coupling Weld Due to Fabrication Defect.Reactor Shut Down & Weld Repaired ML19345B4491980-11-24024 November 1980 LER 80-086/04L-0:on 801024,condenser Delta T Exceeded Tech Spec Limit.Caused by Increasing Sea Water Temp & Lowering Tide Level ML19345B8431980-11-20020 November 1980 LER 80-085/03L-0:on 801023,HPCI Sys Turbine Reached 150% of 4,000 Rpm Full Flow Speed,Rendering Sys Inoperable.Caused by Failure of Turbine Governor & Resistor in Speed Control Circuitry.Governor & Resistor Replaced ML19339C7761980-11-14014 November 1980 LER 80-080/01T-0:on 801031,reactor Vessel Relief Valve Rv 203-3A Opened.Caused by Nitrogen Regulator Valve Which Froze in Open Position.Drywell Instruments Will Be Operated by Compressed Air W/Nitrogen Supply Isolated ML19339C7661980-11-13013 November 1980 LER 80-078/01T-0:on 801030,review of Results of Salt Svc Water Sys Per IE Bulletin 79-14,indicated Design Deficiency. Caused by Installation of Salt Svc Water Anchor Point Outside Area Tornado Missile Barrier Protection ML19339C0671980-11-0808 November 1980 LER 80-083/04T-0:on 801103,analyses Rept Indicated That Concentration of Cs-137 Found in Cranberries from Manomet Point Bog on 800919 Was 354 Picocuries/Kg.Caused by Fallout ML19339C5901980-11-0707 November 1980 LER 80-082/03L-0:on 801008,containment Isolation Valve MO-1001-34B Did Not Close When Actuated by Control Switch. Caused by Failure of Valve Torque Switch.Valve Replaced, Satisfactorily Tested & Returned to Svc ML19339B1961980-10-31031 October 1980 LER 80-079/03L-0:on 801001,following Scram,D Relief Valve Stuck Open Causing Complete Depressurization of Reactor. Probably Caused by Scoring on Main Piston.Valve Replaced ML19339A8101980-10-30030 October 1980 LER 80-077/03L-0:on 800930,excessive Moisture in Sample Lines Prevented Chemical Personnel from Obtaining Representative Sample of Drywell Atmosphere.Caused by Condensation Accumulating in Lines & Saturating C-19 ML19339A6821980-10-27027 October 1980 LER 80-072/01T-0:on 801002,reactor Protection Sys Trip Level Setting Was Adjusted to Nonconservative Level Due to Calculation Error.Procedure 7.4.14 Being Processed to Clearly Delineate Method for Calculating Set Points ML19339B9321980-10-27027 October 1980 LER 80-061/03X-1:on 800825,surveillance Testing,Initiated Because of HPCI Sys Failure,Determined That a Loop of Core Spray Sys Was Inoperable.Caused by Core Spray Valve Mo 1400-24A Being Partially Stuck Open ML19338G1951980-10-23023 October 1980 LER 80-076/03L-0:on 800923,flow Integrator Fq 7032 for Drywell Floor Sump Pump Was Not Operating.Cause Undetermined ML19338G0761980-10-22022 October 1980 LER 80-074/04L-0:on 790125,0228 & 0301,condenser Delta T, Difference Between Intake & Discharge Canals Sea Water Temp, Exceeded Tech Specs.Caused by Condenser Tube Sheet Fouling & Low Tide.Power Reductions & Condenser Backwashes Initiated ML19338G1411980-10-22022 October 1980 LER 80-070/01T-0:on 801010,480 Volt Breaker 52-204 Tripped Twice within 10 Minutes de-energizing 480 Volt Bus B14, Disabling Loop a of Rbccw.Cause Unknown.Breaker Closed,Bus Returned to Svc & Loop a Returned to Normal 1993-07-28
[Table view] Category:RO)
MONTHYEARML20046C3131993-07-28028 July 1993 LER 93-015-00:on 930630,HPCI Sys Declared Inoperable Due to Indicated Flow During Surveillance.Caused by Foreign Matl That Plugged Portion of Restricting Orifice.Restricting Orifice Removed,Cleaned & reinstalled.W/930728 Ltr ML20045E2301993-06-25025 June 1993 LER 93-013-00:on 930530,RCIC Sys Declared Inoperable & 7 Day TS 3.5.D.2 LCO Entered Due to Speed Oscillations Which Occurred After Several Minutes of steady-state Operation. Caused by Actuator Failure.Actuator replaced.W/930625 Ltr ML20045D1861993-06-18018 June 1993 LER 93-010-00:on 930519,SUT Became de-energized During Planned Calibr of Turbine/Generator Relays Lockout Test While Shut Down.Caused by Personnel Error.Discussion Conducted W/Personnel Re Attention to detail.W/930618 Ltr ML20044H0441993-06-0202 June 1993 LER 93-009-00:on 930504,circuit Breaker Did Not Close During Planned Bus Transfer Due to Loose Control Circuit Wire.Lug Replaced & Reterminated on 930505 & Post Work Testing Completed W/Satisfactory results.W/930602 Ltr ML20012F5751990-04-0606 April 1990 LER 90-003-00:on 900311,automatic Actuation of Main Steam Sys Group 1 Portion of Primary Containment Isolation Control Sys Occurred.Caused by False High Reactor Vessel Water Level Signal.Procedure Developed Re backfill.W/900406 Ltr ML20012E9831990-03-30030 March 1990 LER 90-002-00:on 900228,determined That Max Fraction of Limiting Power Density Not Checked Daily During Reactor Power Operation,Per Tech Spec 4.1.B.On 900323,addl Tech Spec Issue Discovered.Tech Specs changed.W/900330 Ltr ML20011D1361989-12-11011 December 1989 LER 89-035-00:on 891111,inadvertent Actuation of Portion of Secondary Containment Sys During Surveillance Testing Occurred.Caused by Location of Radiation Isolation Control Sys Channel a Logic Relay.Procedure revised.W/891211 Ltr ML20005D7421989-12-0606 December 1989 LER 89-033-00:on 891106,automatic Actuation of Group 1 Portion of Primary Containment Isolation Control Sys (PCIS) Occurred.Caused by High Reactor Vessel Water Level.Manual Valve Closed & PCIS Logic Circuitry reset.W/891206 Ltr ML19332D1421989-11-22022 November 1989 LER 89-031-00:on 891024,closing Times for Two in-series Primary Containment Isolation Valves Exceeded Acceptance Criteria During Shutdown Testing.Cause Undetermined.Closing Time Retested W/Satisfactory results.W/891122 Ltr ML19332D6231989-11-20020 November 1989 LER 89-032-00:on 891020,pneumatic Pressure Drop for Two of Four Automatic Depressurization Sys Accumulators Discovered Greater than Max Acceptable Value.Caused by Leakage from Seat of Supply Check Valves.Seat replaced.W/891120 Ltr ML19324C3181989-11-0909 November 1989 LER 88-002-01:on 880117,full Reactor Protection Sys Scram Trip Signal Occurred During Surveillance Test,Resulting in Incomplete Actuations.Caused by Procedure Inadequacy.Logic Relay Replaced & Procedure revised.W/891109 Ltr ML19324B1131989-10-21021 October 1989 LER 89-030-00:on 890926,control Room High Efficiency Air Filtration Sys Flowrate non-conservative Due to Procedure Error.Caused by Transcription Error.Procedure Revised & Test Reperformed Using Corrected procedure.W/891021 Ltr ML19325D4681989-10-16016 October 1989 LER 89-029-00:on 890914,locked High Radiation Area Door Found to Have Been Unsecured Contrary to Tech Spec 6.13.2. Caused by Failure to Adhere to Approved Procedures. Training on Access Requirements initiated.W/891016 Ltr ML19325D1861989-10-10010 October 1989 LER 89-028-00:on 890907,HPCI Sys Declared Inoperable Because Mechanical Overspeed Trip Occurred During Surveillance Test. Caused by Failure of Ramp Generator Signal Converter Module. Module Removed & Sent to Mfg for exam.W/891010 Ltr ML17277B8221984-07-20020 July 1984 LER 82-049/01X-1:on 821102,main Steam Line Safety Valve a Set W/Nitrogen at Steam Relief Setting.Caused by Personnel Error.Valve Removed & Replaced W/Properly Set Spare Valve. Procedure revised.W/840720 Ltr ML20024C3231983-06-24024 June 1983 Updated LER 82-038/03X-1:on 820817,RCIC Steam Line High Differential Pressure Alarm Received.Caused by Air in Sensing Lines to Pressure Switches.Cross Threaded Cap Found on in-line Snubber.Snubber replaced.W/830624 Ltr ML20023D0181983-05-0404 May 1983 LER 83-022/03L-0:on 830413,overload on Valve Motor 1301-17 Resulted in Loss of High Pressure Core Cooling Backup Capability.Caused by Oxidation in Motor End Bell & Motor Brushes,Due to Humidity Caused by Leaking Valve Packing ML20027C9801982-10-20020 October 1982 LER 82-039/03L-0:on 820920,timing Tests of Three Reactor Water Cleanup Isolation Valves 1201-2,-5 & -80 Not Completed within Allowed Time.Caused by Operational Constraints Requiring Testing at Reduced Power ML20042A7461982-03-12012 March 1982 LER 82-005/01T-0:on 820226,deficiencies in Pipe Supports in Control Rod Driveline Insert & Withdraw Lines Identified. Caused by Missing or Loose Clamps.Restoration to Acceptable Limits Will Be Completed Before End of Cycle VI ML20041F1901982-03-0202 March 1982 LER 82-003/99L-0:on 820201,util Changed Corporate Organization.Senior vice-president Elected & vice-president & Director of Operations Review Created.Change Prompted by Need to Incorporate Oversight of safety-related Activities ML20052G0581982-02-27027 February 1982 LER 82-005/01X-0:on 820226,station Informed That Max Stresses Above Acceptable Limits in Piping Supports of Control Rod Drive Insert & Withdrawal Lines.Caused by Imcomplete Const.Restoration Will Be Completed ML20049H7761982-02-16016 February 1982 LER 82-002/03L-0:on 820118,sensing Line to Pressure Switch Found Frozen.Line Froze Again on 820119.On 820123,fire Pump Found Out of Calibr.Caused by Subzero Weather Which Reduced Effectiveness of Heating Sys.Priority Maint Requests Issued ML20041A1491982-02-0404 February 1982 LER 82-001/03L-0:on 820105,during Refueling Outage,Sliding Fire Door Found Nonfunctional During Fire Insp.Caused by Metal Channel Hindering Door Movement.All Personnel Apprised of Procedural Responsibilities ML20040F3211982-01-26026 January 1982 LER 81-065/03L-0:on 811230,during Investigation of Failure of MSIV AO-203-2A,discovered Two hold-down Bolts on Poppet W/O Lock Plates.Caused by Failure to Follow Procedures During Previous Valve Overhaul ML20039B0711981-12-0909 December 1981 LER 81-063/04T-0:on 811130,Yankee Atomic Environ Lab Rept Received Indicating Reportable Concentration of Cs-137 in Cranberry Sample from Manomet Point Bog.Apparently Caused by Previous Weapons Testing & Inadequate Potassium in Soil ML20049A8191981-09-22022 September 1981 LER 81-047/03L-0:on 810824,during Surveillance Test,One Channel of Rod Block Monitor Found to Be Not Functional. Caused by Failed Zener Diode on Flow Control Trip Ref Unit. Unit Replaced ML19350F0071981-06-16016 June 1981 Updated LER 81-018/03X-1:on 810512,stack Gas Radiation Monitor 1705-18A Was Downscale & Inoperable Following Lightning Strike Near Main Stack.Caused by Voltage Surge Resulting in Preamplifier & Discriminator Circuits Failure ML19350E2831981-06-10010 June 1981 LER 81-019/03L-0:on 810514,level Recorder 5049 Was Found Indicating High.Caused by Calibr Shift Due to Jarring Instrument Sensing Lines During Installation of Torus Room Staging.Recorder & Transmitters Recalibr ML19352B2021981-05-28028 May 1981 LER 81-016/03L-0:on 810430,reactor Core Isolation Cooling Valve Mo 1301-17 Failed to Close on Demand Following Switch Actuation.Caused by Deteriorated Packing Jammed Between Valve Stem & Packing Gland.Packing Replaced ML20004D7451981-05-18018 May 1981 Updated LER 80-058/03L-1:on 800821,while Conducting HPCI Sys Test,Hpci Sys Declared Inoperable.Possibly Caused by Dirt Which Caused Temporary Malfunction of Turbine Throttle Valve.Tests by Factory Representative Satisfactory ML20003D5371981-03-19019 March 1981 LER 81-007/03L-0:on 810217,reactor Coolant Leak Detection Air Sampling Sys Declared Inoperable.Caused by Blown Fuses. Fuses Replaced.Pump Will Be Rebuilt ML19350B5141981-03-10010 March 1981 LER 81-004/01T-0:on 810225,review Indicated That If Backup Scram Solenoids Failed,Actuation of ATWS Sys Would Prevent Closure of Scram Discharge Vol Vent & Drain Valves,Violating Primary Containment.Cause Due to Oversight in Design ML20003C6741981-03-0202 March 1981 LER 81-005/03L-0:on 810202,unidentified Reactor Drywell Coolant Leakage Rates Measured Above Tech Spec Level.Cause Not Stated.Recirculation Pump Suction Valves a & B & Discharge Valves Backseated ML20003B2571981-02-0606 February 1981 LER 81-002/03L-0:on 810107,main Stack Sample Flow Alarm Received Twice on Panel C903 in Control Room.Caused by Frozen Suction Line (First Occurrence) & Blown Power Supply Fuse (Second Occurrence) ML19345E1581980-12-17017 December 1980 LER 80-089/03L-0:on 801117,torus Water Level Indicator Lr 5038 on Panel C903 in Control Room Began to Oscillate Irradically.Instrument Declared Inoperable.Caused by Failure of Forced Balanced Motor Boyancy Level Transmitter ML19351E6561980-11-28028 November 1980 LER 80-084/01X-1:on 801113,water Leak Discovered from 2- Inch Reactor Vessel Drain Line.Caused by Faulty Weld.Weld Isolated & Ground Out.Coupling Rewelded ML19345B8581980-11-28028 November 1980 LER 80-084/01X-0:on 801113,leak Discovered in 2-inch Reactor Vessel Drain Line Connected to Reactor Water Cleanup Sys. Caused by Slag Inclusions in Pipe Coupling Weld Due to Fabrication Defect.Reactor Shut Down & Weld Repaired ML19345B4491980-11-24024 November 1980 LER 80-086/04L-0:on 801024,condenser Delta T Exceeded Tech Spec Limit.Caused by Increasing Sea Water Temp & Lowering Tide Level ML19345B8431980-11-20020 November 1980 LER 80-085/03L-0:on 801023,HPCI Sys Turbine Reached 150% of 4,000 Rpm Full Flow Speed,Rendering Sys Inoperable.Caused by Failure of Turbine Governor & Resistor in Speed Control Circuitry.Governor & Resistor Replaced ML19339C7761980-11-14014 November 1980 LER 80-080/01T-0:on 801031,reactor Vessel Relief Valve Rv 203-3A Opened.Caused by Nitrogen Regulator Valve Which Froze in Open Position.Drywell Instruments Will Be Operated by Compressed Air W/Nitrogen Supply Isolated ML19339C7661980-11-13013 November 1980 LER 80-078/01T-0:on 801030,review of Results of Salt Svc Water Sys Per IE Bulletin 79-14,indicated Design Deficiency. Caused by Installation of Salt Svc Water Anchor Point Outside Area Tornado Missile Barrier Protection ML19339C0671980-11-0808 November 1980 LER 80-083/04T-0:on 801103,analyses Rept Indicated That Concentration of Cs-137 Found in Cranberries from Manomet Point Bog on 800919 Was 354 Picocuries/Kg.Caused by Fallout ML19339C5901980-11-0707 November 1980 LER 80-082/03L-0:on 801008,containment Isolation Valve MO-1001-34B Did Not Close When Actuated by Control Switch. Caused by Failure of Valve Torque Switch.Valve Replaced, Satisfactorily Tested & Returned to Svc ML19339B1961980-10-31031 October 1980 LER 80-079/03L-0:on 801001,following Scram,D Relief Valve Stuck Open Causing Complete Depressurization of Reactor. Probably Caused by Scoring on Main Piston.Valve Replaced ML19339A8101980-10-30030 October 1980 LER 80-077/03L-0:on 800930,excessive Moisture in Sample Lines Prevented Chemical Personnel from Obtaining Representative Sample of Drywell Atmosphere.Caused by Condensation Accumulating in Lines & Saturating C-19 ML19339A6821980-10-27027 October 1980 LER 80-072/01T-0:on 801002,reactor Protection Sys Trip Level Setting Was Adjusted to Nonconservative Level Due to Calculation Error.Procedure 7.4.14 Being Processed to Clearly Delineate Method for Calculating Set Points ML19339B9321980-10-27027 October 1980 LER 80-061/03X-1:on 800825,surveillance Testing,Initiated Because of HPCI Sys Failure,Determined That a Loop of Core Spray Sys Was Inoperable.Caused by Core Spray Valve Mo 1400-24A Being Partially Stuck Open ML19338G1951980-10-23023 October 1980 LER 80-076/03L-0:on 800923,flow Integrator Fq 7032 for Drywell Floor Sump Pump Was Not Operating.Cause Undetermined ML19338G0761980-10-22022 October 1980 LER 80-074/04L-0:on 790125,0228 & 0301,condenser Delta T, Difference Between Intake & Discharge Canals Sea Water Temp, Exceeded Tech Specs.Caused by Condenser Tube Sheet Fouling & Low Tide.Power Reductions & Condenser Backwashes Initiated ML19338G1411980-10-22022 October 1980 LER 80-070/01T-0:on 801010,480 Volt Breaker 52-204 Tripped Twice within 10 Minutes de-energizing 480 Volt Bus B14, Disabling Loop a of Rbccw.Cause Unknown.Breaker Closed,Bus Returned to Svc & Loop a Returned to Normal 1993-07-28
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEAR05000293/LER-1999-010-02, :on 990918,reactor Startup Was in Progress. Caused by Communications Breakdown That Resulted in Operations Personnel Failing to Complete Actions in IAW Procedures.Power Ascension Was Secured.With1999-10-18018 October 1999
- on 990918,reactor Startup Was in Progress. Caused by Communications Breakdown That Resulted in Operations Personnel Failing to Complete Actions in IAW Procedures.Power Ascension Was Secured.With
05000293/LER-1999-009-02, :on 990913,manual Scram at 27 Percent Power, Occurred.Caused by Degrading Main Condenser Vacuum. Inspection of Instrument Sensing Lines to E-306B Level Transmitters Was Performed.With1999-10-13013 October 1999
- on 990913,manual Scram at 27 Percent Power, Occurred.Caused by Degrading Main Condenser Vacuum. Inspection of Instrument Sensing Lines to E-306B Level Transmitters Was Performed.With
ML20217E3021999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for Pilgrim Nuclear Station.With ML20216G5991999-09-24024 September 1999 Corrected Safety Evaluation Supporting Amend 182 to License DPR-35,consisting of Corrected Page 1 ML20212C2921999-09-16016 September 1999 SER Accepting Licensee Request for Relief from ASME Code Section XI Requirements as Endorsed by 10CFR50.55a for Containment Insp for Pilgrim Nuclear Power Station ML20216F3511999-09-0808 September 1999 ISI Summary Rept for Refuel Outage 12 at Pnps 05000293/LER-1999-008-02, :on 990805,automatic Scram Occurred While at 100% Power Due to Automatic Turbine Trip.Caused by Malfunction of Moisture Separator Drain Tank a Drain Valve Controller.Level Controllers Replaced.With1999-09-0707 September 1999
- on 990805,automatic Scram Occurred While at 100% Power Due to Automatic Turbine Trip.Caused by Malfunction of Moisture Separator Drain Tank a Drain Valve Controller.Level Controllers Replaced.With
ML20216E6881999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Pilgrim Nuclear Power Station.With 05000293/LER-1999-007-02, :on 990716,discovered That Bus B6 Voltage Restoration Was Not Consistent with Safety Analysis Assumptions.Caused by Personnel Error During Development of Design Change.Will Evaluate Need for Mod.With1999-08-13013 August 1999
- on 990716,discovered That Bus B6 Voltage Restoration Was Not Consistent with Safety Analysis Assumptions.Caused by Personnel Error During Development of Design Change.Will Evaluate Need for Mod.With
05000293/LER-1999-006-02, :on 990705,both EDGs Were Inoperable.Caused by Ambient Air Temp Exceeding 88 Degrees Fahrenheit.Temporary Mods Tm 99-41 & Tm 99-42,implemented for EDG a Were Completed on 990706.With1999-08-0404 August 1999
- on 990705,both EDGs Were Inoperable.Caused by Ambient Air Temp Exceeding 88 Degrees Fahrenheit.Temporary Mods Tm 99-41 & Tm 99-42,implemented for EDG a Were Completed on 990706.With
ML20210R3401999-07-31031 July 1999 Monthly Operating Rept for July 1999 for Pilgrim Nuclear Power Station.With ML20209G3851999-07-15015 July 1999 Safety Evaluation Supporting Amend 182 to License DPR-35 05000293/LER-1999-005, :on 990608,partial Actuation of Rhr/Lpci Circuitry During Surveillance Test Was Noted.Caused by Personnel Error.Revised Procedure.With1999-07-0808 July 1999
- on 990608,partial Actuation of Rhr/Lpci Circuitry During Surveillance Test Was Noted.Caused by Personnel Error.Revised Procedure.With
ML20209C4731999-07-0707 July 1999 Addendum to SE on Proposed Transfer of Operating License & Matls License from Boston Edison Co to Entergy Nuclear Generation Co ML20209H8251999-07-0101 July 1999 Provides Commission with Evaluation of & Recommendations for Improvement in Processes Used in Staff Review & Approval of Applications for Transfer of Operating Licenses of TMI-1 & Pilgrim Station ML20209E6191999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Pilgrim Nuclear Power Station.With ML20196H2451999-06-29029 June 1999 SER Denying Licensee Proposed Alternative in Relief Request PRR-13,rev 2.Staff Determined That Proposed Alternative Provides Insufficient Info to Determine Adequacy of Scope of Implementation ML20209A8901999-06-28028 June 1999 SER Accepting Licensee Proposed Alternative to Use Code Case N-573 for Remainder of 10-year Interval Pursuant to 10CFR50.55a(a)(3)(i) 05000293/LER-1999-004, :on 990529,setpoint of Target Rock Relief Valves Were Found Out of Tolerance During Testing.Caused by Setpoint Drift.Replaced Pilot Assemblies with Certified Spare Pilot Assemblies.With1999-06-28028 June 1999
- on 990529,setpoint of Target Rock Relief Valves Were Found Out of Tolerance During Testing.Caused by Setpoint Drift.Replaced Pilot Assemblies with Certified Spare Pilot Assemblies.With
ML20209B9861999-06-23023 June 1999 Rev 13A to Pilgrim Nuclear Power Station COLR for Cycle 13 ML20217N9061999-06-21021 June 1999 Rept of Changes,Tests & Experiments for Period of 970422-990621 05000293/LER-1999-003, :on 990516,discovered That LLRT Results Exceeded Allowable TS Leakage Rates.Cause Indeterminate. Affected Valves Were Disassembled & Inspected & Damaged or Worn Parts Were Reworked or Replaced.With1999-06-15015 June 1999
- on 990516,discovered That LLRT Results Exceeded Allowable TS Leakage Rates.Cause Indeterminate. Affected Valves Were Disassembled & Inspected & Damaged or Worn Parts Were Reworked or Replaced.With
ML20195K3431999-06-15015 June 1999 Safety Evaluation Granting Licensee Request to Use Guidance of GL 90-05 to Repair Flaws in ASME Class 3 Salt Svc Water System Piping for Plant 05000293/LER-1999-002, :on 990504,HPCI & RCIC Sys Surveillance Testing Outside Design Bases,Was Identified.Caused by Incorrect Ts. Proposed License Amend to Change TS Surveillance Testing Requirements,Submitted on 990511.With1999-06-0303 June 1999
- on 990504,HPCI & RCIC Sys Surveillance Testing Outside Design Bases,Was Identified.Caused by Incorrect Ts. Proposed License Amend to Change TS Surveillance Testing Requirements,Submitted on 990511.With
ML20195G8231999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Pnps.With ML20207E7471999-05-27027 May 1999 Safety Evaluation Granting Request Re Reduction of IGSCC Insp of Category D Welds Due to Implementation of HWC to License DPR-35 ML20206M1971999-05-11011 May 1999 SER Accepting Request for Approval to Repair Flaws in ASME Code Class 3 Salt Svc Water Piping at Plant 05000293/LER-1999-001, :on 990412,environ Enclosures of MCCs Outside Design Basis,Were Found.Caused by Failure to Translate Design Function of Pressure Relieving Devices.Removed Obstructions of Pressure Relieving Devices.With1999-05-0606 May 1999
- on 990412,environ Enclosures of MCCs Outside Design Basis,Were Found.Caused by Failure to Translate Design Function of Pressure Relieving Devices.Removed Obstructions of Pressure Relieving Devices.With
ML20206J6611999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Pilgrim Nuclear Power Station.With ML20205L0221999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Pilgrim Nuclear Power Station.With ML20207J5471999-03-0909 March 1999 Training Simulator,1999 4-Yr Certification Rept ML20207F9401999-03-0101 March 1999 Long Term Program Semi-Annual Rept for Pilgrim Nuclear Power Station ML20207H5451999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Pilgrim Nuclear Power Station.With 05000293/LER-1998-029, :on 981231,discovered That Intake Structure Indoor Air Temp Was Less than Winter Design Temp,Per Ufsar. Caused by Lack of Info & Administrative Controls.Will Repair Ventilation Sys & Will Revise Procedures.With1999-02-0101 February 1999
- on 981231,discovered That Intake Structure Indoor Air Temp Was Less than Winter Design Temp,Per Ufsar. Caused by Lack of Info & Administrative Controls.Will Repair Ventilation Sys & Will Revise Procedures.With
05000293/LER-1998-028, :on 981230,CR High Efficiency Air Filtration Sys Relative Humidity Switches Were Inoperable.Caused by Gradual Degradation of Nylon Filaments.Modified Sys Control Circuitry.With1999-01-28028 January 1999
- on 981230,CR High Efficiency Air Filtration Sys Relative Humidity Switches Were Inoperable.Caused by Gradual Degradation of Nylon Filaments.Modified Sys Control Circuitry.With
ML20206Q2741998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for Pilgrim Nuclear Power Station.With ML20196E2151998-12-31031 December 1998 1998 Annual Rept for Boston Edison & Securities & Exchange Commission Form 10-K Rept.With 05000293/LER-1998-026, :on 981202,HPCI Sys Declared Inoperable.Caused by Failed Power Inverter.Failed Inverter Replaced. with1998-12-23023 December 1998
- on 981202,HPCI Sys Declared Inoperable.Caused by Failed Power Inverter.Failed Inverter Replaced. with
05000293/LER-1998-007, :on 980330,single Failure Vulnerability of RHR Sys When in Suppression Pool Cooling Mode Was Noted.Caused by Inadequate Original Design.Problem Rept Pr 98.9159 Was Written to Document Concern.With1998-12-22022 December 1998
- on 980330,single Failure Vulnerability of RHR Sys When in Suppression Pool Cooling Mode Was Noted.Caused by Inadequate Original Design.Problem Rept Pr 98.9159 Was Written to Document Concern.With
ML20198H5671998-12-21021 December 1998 Safety Evaluation Supporting Amend 180 to License DPR-35 05000293/LER-1998-018, :on 980722,EDGs Were Declared Inoperable When Ambient Air Temp Exceeded 88 F.Caused by Inadequate EDG Cooling & Bldg Ventilation Design.Will Develop EDG Cooling & EDG Bldg Ventilation Modifications.With1998-12-18018 December 1998
- on 980722,EDGs Were Declared Inoperable When Ambient Air Temp Exceeded 88 F.Caused by Inadequate EDG Cooling & Bldg Ventilation Design.Will Develop EDG Cooling & EDG Bldg Ventilation Modifications.With
05000293/LER-1997-017, :on 971104,past Operation with SW Temps Were Greater than Design.Caused by Licensing Basis Ambiguity. Issued SE & License Amend Request Was Submitted.With1998-12-18018 December 1998
- on 971104,past Operation with SW Temps Were Greater than Design.Caused by Licensing Basis Ambiguity. Issued SE & License Amend Request Was Submitted.With
05000293/LER-1998-004, :on 980321,EDG Room Air Temp Was Below Design Basis.Caused by Significant Effect of Meteorogical Conditions.Completed Engineering Evaluation1998-12-18018 December 1998
- on 980321,EDG Room Air Temp Was Below Design Basis.Caused by Significant Effect of Meteorogical Conditions.Completed Engineering Evaluation
05000293/LER-1998-025, :on 981118,setpoint of Target Rock Relief Valve Was Found out-of-tolerance During Testing.Caused by Setpoint Drift.Valve Was Disassembled,Inspected & Reworked by Target Rock Corp Personnel.With1998-12-18018 December 1998
- on 981118,setpoint of Target Rock Relief Valve Was Found out-of-tolerance During Testing.Caused by Setpoint Drift.Valve Was Disassembled,Inspected & Reworked by Target Rock Corp Personnel.With
ML20198A2391998-12-11011 December 1998 Safety Evaluation Supporting Amend 179 to License DPR-35 ML20197J3591998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Pilgrim Nuclear Power Station.With 05000293/LER-1998-024, :on 981015,determined That CR High Efficiency Aire Filtration Sys (Crheafs) Found Outside Design Basis Due to Installation of Duct Tape on Trains a & B Crheafs Supply Fans.Installed Mechanical Seals on Crheafs Supply Fans1998-11-13013 November 1998
- on 981015,determined That CR High Efficiency Aire Filtration Sys (Crheafs) Found Outside Design Basis Due to Installation of Duct Tape on Trains a & B Crheafs Supply Fans.Installed Mechanical Seals on Crheafs Supply Fans
ML20195B9161998-11-10010 November 1998 Safety Evaluation Supporting Amend 178 to License DPR-35 05000293/LER-1998-023, :on 981005,incorrect Wiring Mods Affected RBCCW Train B Alternate Shutdown Panel.Caused by Error Made During Preparation of Electrical Connection Drawing to Implement Plant Design.Blown Fuse Replaced.With1998-11-0404 November 1998
- on 981005,incorrect Wiring Mods Affected RBCCW Train B Alternate Shutdown Panel.Caused by Error Made During Preparation of Electrical Connection Drawing to Implement Plant Design.Blown Fuse Replaced.With
ML20195C9951998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Pilgrim Nuclear Power Station.With 1999-09-08
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