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| NRC%%dmI 366A'4/<<2(Y EA R"Q'.6 0 5 0 0 0 315 9]SEQUENTIAL P/'+NUMB E II.<BX 0 0 II 6 V IS I 0 N NUMEEII 01 02 0 3 Conditions Prior to Occurrence Unit One in Mode One at 100 Percent Rated Thermal Power.Descri tion of Event On August 19, 1991, during routine surveillance testing of the full length control rods, Control Bank A was ordered 8 steps into the core by the Rod Control System (EIIS/AA)but appeared not to move into the core by observation of the Analog Rod Position Indication. | | NRC%%dmI 366A'4/<<2(Y EA R"Q'.6 0 5 0 0 0 315 9]SEQUENTIAL P/'+NUMB E II.<BX 0 0 II 6 V IS I 0 N NUMEEII 01 02 0 3 Conditions Prior to Occurrence Unit One in Mode One at 100 Percent Rated Thermal Power.Descri tion of Event On August 19, 1991, during routine surveillance testing of the full length control rods, Control Bank A was ordered 8 steps into the core by the Rod Control System (EIIS/AA)but appeared not to move into the core by observation of the Analog Rod Position Indication. |
| Control Bank A was ordered another 2 steps into the core, leaving both group demand counters at 218 steps.The bank was ordered out of the core 4 steps and an Urgent Alarm was received.Further movement of the rods was discontinued pending investigation of the alarm.It was then noticed that Group 2 remained at 218 steps.The shutdown margin was then verified to known plant conditions at the time.Initial troubleshooting of the Rod Control System found no reason for the Urgent Alarm but it was noted that Power Cabinet 2AC (EIIS/AA-JX) vas selecting Shutdown Bank A instead of Control Bank A.As it was presumed to be selected by the control room, the alarm was reset and the rods were moved per the test requirements and the surveillance completed. | | Control Bank A was ordered another 2 steps into the core, leaving both group demand counters at 218 steps.The bank was ordered out of the core 4 steps and an Urgent Alarm was received.Further movement of the rods was discontinued pending investigation of the alarm.It was then noticed that Group 2 remained at 218 steps.The shutdown margin was then verified to known plant conditions at the time.Initial troubleshooting of the Rod Control System found no reason for the Urgent Alarm but it was noted that Power Cabinet 2AC (EIIS/AA-JX) vas selecting Shutdown Bank A instead of Control Bank A.As it was presumed to be selected by the control room, the alarm was reset and the rods were moved per the test requirements and the surveillance completed. |
| Subsequent discussions with control room personnel indicated that no other rod bank had been selected.At approximately 1200, a rod misalignment in Shutdown Bank A, Group 2 was suspected due to additional small amount of dilution required to keep thermal power at the pre-surveillance level and a decrease in the Analog Rod Position Indication for Shutdown Bank A, Group 2 in relation to pre-surveillance readings.At 1305 hours the flux mapping system was used to determine that the 4 rods of Shutdown Bank A, Group 2 vere inserted approximately 6 steps into the core and entry into Technical Specification 3.0.3 began at this time.The flux mapping system was also used to verify.that any other banks involved with Power Cabinet 2AC vere not misaligned, The banks checked were Control Bank A, Control Bank C and also Shutdovn Bank A, Group 1.At 1403 hours reactor power reduction began and an Unusual Event was declared.Further troubleshooting of the Rod Control System discovered a failure of the 2AC Power Cabinet Multiplexing Relay, MXR-1 (EIIS/AA-RLY). | | Subsequent discussions with control room personnel indicated that no other rod bank had been selected.At approximately 1200, a rod misalignment in Shutdown Bank A, Group 2 was suspected due to additional small amount of dilution required to keep thermal power at the pre-surveillance level and a decrease in the Analog Rod Position Indication for Shutdown Bank A, Group 2 in relation to pre-surveillance readings.At 1305 hours the flux mapping system was used to determine that the 4 rods of Shutdown Bank A, Group 2 vere inserted approximately 6 steps into the core and entry into Technical Specification |
| | |
| | ====3.0.3 began==== |
| | at this time.The flux mapping system was also used to verify.that any other banks involved with Power Cabinet 2AC vere not misaligned, The banks checked were Control Bank A, Control Bank C and also Shutdovn Bank A, Group 1.At 1403 hours reactor power reduction began and an Unusual Event was declared.Further troubleshooting of the Rod Control System discovered a failure of the 2AC Power Cabinet Multiplexing Relay, MXR-1 (EIIS/AA-RLY). |
| It was replaced and proper operation of the Rod Control System was verified.When tested later on the bench, the relay exhibited fluctuating coil circui,t readings out of the circuit.Notification of the event was made on the ENS at 1500 hours.Each of the misaligned rods of Shutdown Bank A was brought out to the top of the core, one at a time, while verifying that reactivity changes remained within limits.The Unusual Event was terminated at 1605 hours.Further research was conducted as to the possibility of the root cause being due to the Stationary B Firing card and/or the Signal Process card.Based on the available information and the satisfactory operating results since the event, the intermittent failure of MXR-1 is believed to be the cause of failure. | | It was replaced and proper operation of the Rod Control System was verified.When tested later on the bench, the relay exhibited fluctuating coil circui,t readings out of the circuit.Notification of the event was made on the ENS at 1500 hours.Each of the misaligned rods of Shutdown Bank A was brought out to the top of the core, one at a time, while verifying that reactivity changes remained within limits.The Unusual Event was terminated at 1605 hours.Further research was conducted as to the possibility of the root cause being due to the Stationary B Firing card and/or the Signal Process card.Based on the available information and the satisfactory operating results since the event, the intermittent failure of MXR-1 is believed to be the cause of failure. |
| NRC FORM 366A (649)u.s.NUCLEAR REGuLATORY COMMISSIO LICENSEE EVENT REPORT (LER)TEXT CONTINUATION APPROVED OMS NO,31504i04 EXPIRES,'4/30/92 tSTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS iNFORMATION COLLECTION REOVEST'00 HRS.FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGtMENT BRANCH IP-530), U.S.NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555.AND TO 1HE PAPERWORK REDUCTION PROJECT 13')504'l04). | | NRC FORM 366A (649)u.s.NUCLEAR REGuLATORY COMMISSIO LICENSEE EVENT REPORT (LER)TEXT CONTINUATION APPROVED OMS NO,31504i04 EXPIRES,'4/30/92 tSTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS iNFORMATION COLLECTION REOVEST'00 HRS.FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGtMENT BRANCH IP-530), U.S.NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555.AND TO 1HE PAPERWORK REDUCTION PROJECT 13')504'l04). |
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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML17335A5641999-10-18018 October 1999 LER 99-024-00:on 990708,literal TS Requirements Were Not Met by Accumlator Valve Surveillance.Caused by Misjudgement Made in Conversion from Initial DC Cook TS to W Std Ts.Submitted License Amend Request.With 991018 Ltr ML17335A5531999-10-0707 October 1999 LER 99-023-00:on 990907,inadequate TS Surveillance Testing of ESW Pump ESF Response Time Noted.Caused by Inadequate Understanding of Plant Design Basis.Surveillance Tests Will Be Revised & Implemented ML17326A1291999-09-17017 September 1999 LER 99-022-00:on 990609,electrical Bus Degraded Voltage Setpoints Too Low for Safety Related Loads,Was Discovered. Caused by Lack of Understanding of Design of Plant.No Immediate Corrective Actions Necessary ML17326A1121999-08-27027 August 1999 LER 99-021-00:on 990728,determined That GL 96-01 Test Requirements Were Not Met in Surveillance Tests.Caused by Failure to Understand Full Extent of GL Requirements. Surveillance Procedures Will Be Revised or Developed ML17326A1011999-08-26026 August 1999 LER 99-020-00:on 990727,EDGs Were Declared Inoperable.Caused by Inadequate Protection of Air Intake,Exhaust & Room Ventilation Structures from Tornado Missile Hazards. Implemented Compensatory Measures in Form of ACs ML17326A0911999-08-16016 August 1999 LER 99-019-00:on 990716,noted Victoreen Containment Hrrms Not Environmentally Qualified to Withstand post-LOCA Conditions.Caused by Inadequate Design Control.Reviewing Options to Support Hrrms Operability in Modes 1-4 ML17326A0771999-08-0404 August 1999 LER 98-029-01:on 980422,noted That Fuel Handling Area Ventilation Sys Was Inoperable.Caused by Original Design Deficiency.Radiological Analysis for Spent Fuel Handling Accidents in Auxiliary Bldg Will Be Redone by 990830 ML17326A0741999-07-29029 July 1999 LER 99-018-00:on 990629,determined That Valve Yokes May Yield Under Combined Stress of Seismic Event & Static,Valve Closed,Stem Thrust.Caused by Inadequate Design of Associated Movs.Operability Determinations Were Performed for Valves ML17326A0661999-07-26026 July 1999 LER 99-017-00:on 990625,noted That Improperly Installed Fuel Oil Return Relief Valve Rendered EDG Inoperable.Caused by Personnel Error.Fuel Oil Return Valve Was Replaced with Valve in Correct Orientation.With 990722 Ltr ML17326A0651999-07-22022 July 1999 LER 98-014-03:on 980310,noted That Response to high-high Containment Pressure Procedure Was Not Consistent with Analysis of Record.Caused by Inadequate Interface with W. FRZ-1 Will Be Revised to Be Consistent with New Analysis ML17326A0491999-07-13013 July 1999 LER 99-016-00:on 990615,TS Requirements for Source Range Neutron Flux Monitors Not Met.Caused by Failure to Understand Design Basis of Plant.Procedures Revised.With 990713 Ltr ML17326A0331999-07-0101 July 1999 LER 99-004-01:on 971030,failure to Perform TS Surveillance Analyses of Reactor Coolant Chemistry with Fuel Removed Was Noted.Caused by Ineffective Mgt of Tss.Chemistry Personnel Have Been Instructed on Requirement to Follow TS as Written ML17326A0151999-06-18018 June 1999 LER 99-014-00:on 990521,determined That Boron Injection Tank Manway Bolts Were Not Included in ISI Program,Creating Missed Exam for Previous ISI Interval.Caused by Programmatic Weakness.Isi Program & Associated ISI Database Modified ML17325B6311999-06-0101 June 1999 LER 99-S03-00:on 990430,vital Area Barrier Degradation Was Noted.Caused by Inadequate Insp & Maint of Vital Area Barrier.Repairs & Mods Were Made to Barriers to Eliminate Degraded & Nonconforming Conditions ML17325B6421999-06-0101 June 1999 LER 99-013-00:on 990327,safety Injection & Centrifugal Charging Throttle Valve Cavitation During LOCA Could Have Led to ECCS Pump Failure.Caused by Inadequate Original Design Application of Si.Throttle Valves Will Be Developed ML17325B6351999-05-28028 May 1999 LER 99-S02-00:on 990428,vulnerability in Safeguard Sys That Could Allow Unauthorized Access to Protected Area Was Noted. Caused by Inadequate Original Plant Design.Mods Were Made to Wall Opening to Eliminate Nonconforming Conditions ML17265A8231999-05-24024 May 1999 LER 98-037-01:on 990422,determined That Ice Condenser Bypass Leakage Exceeds Design Basis Limit.Caused by Pressure Seal Required by Revised W Design Not Incorporated Into Aep Design.Numerous Matl Condition Walkdowns & Assessments Made ML17325B6001999-05-20020 May 1999 LER 99-012-00:on 990420,concluded That Auxiliary Bldg ESF Ventilation Sys Not Capable of Maintaining ESF Room Temps post-accident.Caused by Inadequate Control of Sys Design Inputs.Comprehensive Action Plan Being Developed ML17325B5861999-05-10010 May 1999 LER 99-002-00:on 990415,discovered That TS 4.0.5 Requirements Were Not Met Due to Improperly Performed Test. Caused by Incorrect Interpretation of ASME Code.App J Testing Will Be Completed & Procedures Will Be Revised ML17325B5811999-05-0404 May 1999 LER 99-011-00:on 990407,air Sys for EDG Will Not Support Long Operability.Caused by Original Design Error.Temporary Mod to Supply Makeup Air Capability in Modes 5 & 6 Was Prepared ML17325B5771999-05-0303 May 1999 LER 99-010-00:on 990401,RCS Leak Detection Sys Sensitivity Not in Accordance with Design Requirements Occurred.Caused by Inadequate Original Design of Containment Sump Level. Evaluation Will Be Performed to Clearly Define Design ML17325B5581999-04-16016 April 1999 LER 99-006-00:on 990115,personnel Identified Discrepancy Between TS 3.9.7 Impact Energy Limit & Procedure 12 Ohp 4030.STP.046.Caused by Lack of Design Basis Control.Placed Procedure 12 Ohp 4030.STP.046 on Administrative Hold ML17325B5471999-04-12012 April 1999 LER 99-009-00:on 990304,as-found RHR Safety Relief Valve Lift Setpoint Greater than TS Limit Occurred.Cause Investigation for Condition Has Not Been Completed.Update to LER Will Be Submitted,Upon Completion of Investigation ML17325B5321999-04-0707 April 1999 LER 99-S01-00:on 990308,discovered That Lock for Vital Gate Leading to Plant 4KV Switchgear Area Was Nonconforming & Vulnerable to Unauthorized Access.Caused by Inadequate Gate Design & Inadequate Procedures.Mods Are Being Made to Gate ML17325B5161999-04-0101 April 1999 LER 99-007-00:on 981020,calculations Showed That Divider Barrier Between Upper & Lower Containment Vols Were Overstressed.Engineers Are Currently Working on Analyses of Loads & Stress on Enclosures ML17325B5221999-03-29029 March 1999 LER 99-001-00:on 960610,degraded Component Cooling Water Flow to Containment Main Steam Line Penetrations,Identified on 990226.Caused by Inadequate Understanding of Design Basis.Additional Investigations Ongoing ML17325B4801999-03-18018 March 1999 LER 99-004-00:on 971030,failure to Perform TS Surveillance Analyses of Rc Chemistry with Fuel Removed Was Noted.Cause of Event Is Under Investigation.Corrected Written Job Order Activities Used to Control SD Chemistry Sampling ML17325B4741999-03-18018 March 1999 LER 99-005-00:on 940512,determined That Rt Breaker Manual Actuations During Rod Drop Testing Were Not Previously Reported.Caused by Lack of Training.Addl Corrective Actions,Including Preventative Actions May Be Developed ML17325B4571999-02-24024 February 1999 LER 99-003-00:on 990107,CR Pressurization Sys Surveillance Test Did Not Test Sys in Normal Operating Condition.Caused by Failure to Recognize Door 12DR-AUX415 as Part of CR Pressure Boundary.Performed Walkdown of Other Doors ML17335A5171999-02-11011 February 1999 LER 99-002-00:on 990112,determined That RCS Pressurizer PORVs Had Not Been Tested,Per Ts.Caused by Inadequate Scheduling Controls Allowing Personnel Error.Surveillance Procedure Was Completed & Updated LER Will Be Submitted ML17335A5141999-02-10010 February 1999 LER 99-001-00:on 990106,noted That GE Hfa Relays Installed in EDGs May Not Meet Seismic Qualification.Caused by Operating Experience Info Incorrectly Dispositioned in 1985. Updated LER Will Be Submitted by 990405 ML17335A5011999-02-0101 February 1999 LER 98-060-00:on 981231,identified That Rt Sys Response Time Testing Did Not Comply with TS Definition.Caused by Inadequate Procedures.Corrective Actions Will Be Developed & Update to LER Will Be Submitted by 990415.With 990201 Ltr ML17335A4951999-01-29029 January 1999 LER 98-059-00:on 981230,interim LER -single Failure in Containment Spray Sys Could Result in Containment Spray Ph Outside Design Occurred.Investigation Into Condition Continuing.Update Will Be Submitted by 990514 Ltr ML17335A4961999-01-27027 January 1999 LER 98-057-00:on 981228,discovered That AFW Valves Were Not Tested IAW Inservice Testing Program.Caused by Failure to Recognize Design Bases Features Re Afws by Personnel. Updated LER Will Be Submittted by 990415.With 990127 Ltr ML17335A4921999-01-19019 January 1999 LER 98-052-01:on 981128,no Analysis for NSR Sc Manual Loader for Tdafwp Could Be Found in Original Design.Cause Due to All Failure Modes Not Considered When Compressed Air Sys Originally Designed.Performed Review of Components ML17335A4721999-01-0606 January 1999 LER 98-055-00:on 981207,potential for Condition Outside of Design Bases for Rod Control Sys Was Noted.Caused by Calibration Error Coupled with Single Rod Failure.Condition Rept Investigation Is Ongoing ML17335A4691999-01-0606 January 1999 LER 98-056-00:on 981211,hot Leg Nozzle Gaps Resulted in Plant Being in Unanalyzed Condition.Analyses Are Being Performed by W to Resolve Problem.Updated LER Will Be Submitted by 990211.With 990106 Ltr ML17335A4661999-01-0505 January 1999 LER 98-049-00:on 981020,emergency Boron Injection Flow Path Was Inoperable.Caused by Original Design Deficiency. Engineering Evaluation of Event Is Continuing ML17335A4631999-01-0404 January 1999 LER 98-054-00:on 981202,discovered That at Least One MSSV Had Not Been Reset as Required by Ts.Engineering Is Continuing Review of Extent of Condition for Event.Updated LER Will Be Submitted by 990129.With 990104 Ltr ML17335A4481998-12-30030 December 1998 LER 98-053-00:on 981130,discovered Use of Inoperable Substitute Subcooling Margin Monitor.Caused by Condition Existing Since Installation of Plant Process Computer in 1992.Updated LER Will Be Submitted.With 981230 Ltr ML17335A4581998-12-28028 December 1998 LER 98-052-00:on 981128,turbine Driven AFW Pump Speed Controller Failure Mode Occurred.Caused Because Not All Failure Modes Were Considered When Compressed Air Sys Was Originally Designed.Verified Current Design Change Process ML17335A4281998-12-22022 December 1998 LER 98-051-00:on 981122,reactor Trip Signal from Manual Safety Injection Not Verified as Required by TS Surveillance,Was Discovered.Maintenance Currently Evaluating Significance & Cause of Event ML17335A4111998-12-17017 December 1998 LER 98-047-00:on 981117,potential for Increase Leakage from Reactor Coolant Pump Seals Was Identified.Util Is Working with W to Resolve Issue.Current Expectations Are to Submit Update to LER by 990215.With 981217 Ltr ML17335A4141998-12-16016 December 1998 LER 98-058-00:on 981216,postulated High Line Break Could Result in Condition Outside Design Bases for AF Occurred. Caused by Deficiencies Associated with Administration of HELB Program.Analysis of AF Will Be Completed by 990122 ML17335A4181998-12-16016 December 1998 LER 98-050-00:on 980814,ancillary Equipment Installed in Ice Condenser Was Not Designed to Withstand Design Basis Accident/Earthquake Loads.Caused by Lack of Established Design Criteria.Developed Design Criteria ML17335A3871998-12-11011 December 1998 LER 98-031-01:on 980610,potential Common Mode Failure of RHR Pumps Were Noted.Caused by Inaccurate Values.Accurate Miniflow Numbers Have Been Determined by Flow Testing ML17335A3821998-12-0808 December 1998 LER 98-039-01 Re EOP Step Conflicts with Small Break LOCA Analysis.Ler 98-039-00 Has Been Canceled.With 981208 Ltr ML17335A3781998-12-0707 December 1998 LER 98-007-00:on 981106,high Energy Line Break Effects in Auxiliary FW Sys Was Noted.Cause of Event Is Under Investigation & Will Be Completed by 990220.Updated LER Will Be Submitted by 990310.With 981207 Ltr ML17335A3771998-12-0303 December 1998 LER 98-046-00:on 981103,determined That Afs Was Unable to Meet Design Flow Requirements During Special Test.Caused by Failure to Consider All Aspects of Sys Operation in Design of Suction Basket Strainers.Sys Will Be Redesigned ML17335A3741998-12-0202 December 1998 LER 97-011-02:on 970822,operation Was Noted Outside Design Bases for ECCS & CSP for Switchover to Recirculation Sump Suction.Caused by Ineffective Change Mgt.Revised Procedure for Switchover 01(02) Ohp 4023.ES-1.3 1999-09-17
[Table view] Category:RO)
MONTHYEARML17335A5641999-10-18018 October 1999 LER 99-024-00:on 990708,literal TS Requirements Were Not Met by Accumlator Valve Surveillance.Caused by Misjudgement Made in Conversion from Initial DC Cook TS to W Std Ts.Submitted License Amend Request.With 991018 Ltr ML17335A5531999-10-0707 October 1999 LER 99-023-00:on 990907,inadequate TS Surveillance Testing of ESW Pump ESF Response Time Noted.Caused by Inadequate Understanding of Plant Design Basis.Surveillance Tests Will Be Revised & Implemented ML17326A1291999-09-17017 September 1999 LER 99-022-00:on 990609,electrical Bus Degraded Voltage Setpoints Too Low for Safety Related Loads,Was Discovered. Caused by Lack of Understanding of Design of Plant.No Immediate Corrective Actions Necessary ML17326A1121999-08-27027 August 1999 LER 99-021-00:on 990728,determined That GL 96-01 Test Requirements Were Not Met in Surveillance Tests.Caused by Failure to Understand Full Extent of GL Requirements. Surveillance Procedures Will Be Revised or Developed ML17326A1011999-08-26026 August 1999 LER 99-020-00:on 990727,EDGs Were Declared Inoperable.Caused by Inadequate Protection of Air Intake,Exhaust & Room Ventilation Structures from Tornado Missile Hazards. Implemented Compensatory Measures in Form of ACs ML17326A0911999-08-16016 August 1999 LER 99-019-00:on 990716,noted Victoreen Containment Hrrms Not Environmentally Qualified to Withstand post-LOCA Conditions.Caused by Inadequate Design Control.Reviewing Options to Support Hrrms Operability in Modes 1-4 ML17326A0771999-08-0404 August 1999 LER 98-029-01:on 980422,noted That Fuel Handling Area Ventilation Sys Was Inoperable.Caused by Original Design Deficiency.Radiological Analysis for Spent Fuel Handling Accidents in Auxiliary Bldg Will Be Redone by 990830 ML17326A0741999-07-29029 July 1999 LER 99-018-00:on 990629,determined That Valve Yokes May Yield Under Combined Stress of Seismic Event & Static,Valve Closed,Stem Thrust.Caused by Inadequate Design of Associated Movs.Operability Determinations Were Performed for Valves ML17326A0661999-07-26026 July 1999 LER 99-017-00:on 990625,noted That Improperly Installed Fuel Oil Return Relief Valve Rendered EDG Inoperable.Caused by Personnel Error.Fuel Oil Return Valve Was Replaced with Valve in Correct Orientation.With 990722 Ltr ML17326A0651999-07-22022 July 1999 LER 98-014-03:on 980310,noted That Response to high-high Containment Pressure Procedure Was Not Consistent with Analysis of Record.Caused by Inadequate Interface with W. FRZ-1 Will Be Revised to Be Consistent with New Analysis ML17326A0491999-07-13013 July 1999 LER 99-016-00:on 990615,TS Requirements for Source Range Neutron Flux Monitors Not Met.Caused by Failure to Understand Design Basis of Plant.Procedures Revised.With 990713 Ltr ML17326A0331999-07-0101 July 1999 LER 99-004-01:on 971030,failure to Perform TS Surveillance Analyses of Reactor Coolant Chemistry with Fuel Removed Was Noted.Caused by Ineffective Mgt of Tss.Chemistry Personnel Have Been Instructed on Requirement to Follow TS as Written ML17326A0151999-06-18018 June 1999 LER 99-014-00:on 990521,determined That Boron Injection Tank Manway Bolts Were Not Included in ISI Program,Creating Missed Exam for Previous ISI Interval.Caused by Programmatic Weakness.Isi Program & Associated ISI Database Modified ML17325B6311999-06-0101 June 1999 LER 99-S03-00:on 990430,vital Area Barrier Degradation Was Noted.Caused by Inadequate Insp & Maint of Vital Area Barrier.Repairs & Mods Were Made to Barriers to Eliminate Degraded & Nonconforming Conditions ML17325B6421999-06-0101 June 1999 LER 99-013-00:on 990327,safety Injection & Centrifugal Charging Throttle Valve Cavitation During LOCA Could Have Led to ECCS Pump Failure.Caused by Inadequate Original Design Application of Si.Throttle Valves Will Be Developed ML17325B6351999-05-28028 May 1999 LER 99-S02-00:on 990428,vulnerability in Safeguard Sys That Could Allow Unauthorized Access to Protected Area Was Noted. Caused by Inadequate Original Plant Design.Mods Were Made to Wall Opening to Eliminate Nonconforming Conditions ML17265A8231999-05-24024 May 1999 LER 98-037-01:on 990422,determined That Ice Condenser Bypass Leakage Exceeds Design Basis Limit.Caused by Pressure Seal Required by Revised W Design Not Incorporated Into Aep Design.Numerous Matl Condition Walkdowns & Assessments Made ML17325B6001999-05-20020 May 1999 LER 99-012-00:on 990420,concluded That Auxiliary Bldg ESF Ventilation Sys Not Capable of Maintaining ESF Room Temps post-accident.Caused by Inadequate Control of Sys Design Inputs.Comprehensive Action Plan Being Developed ML17325B5861999-05-10010 May 1999 LER 99-002-00:on 990415,discovered That TS 4.0.5 Requirements Were Not Met Due to Improperly Performed Test. Caused by Incorrect Interpretation of ASME Code.App J Testing Will Be Completed & Procedures Will Be Revised ML17325B5811999-05-0404 May 1999 LER 99-011-00:on 990407,air Sys for EDG Will Not Support Long Operability.Caused by Original Design Error.Temporary Mod to Supply Makeup Air Capability in Modes 5 & 6 Was Prepared ML17325B5771999-05-0303 May 1999 LER 99-010-00:on 990401,RCS Leak Detection Sys Sensitivity Not in Accordance with Design Requirements Occurred.Caused by Inadequate Original Design of Containment Sump Level. Evaluation Will Be Performed to Clearly Define Design ML17325B5581999-04-16016 April 1999 LER 99-006-00:on 990115,personnel Identified Discrepancy Between TS 3.9.7 Impact Energy Limit & Procedure 12 Ohp 4030.STP.046.Caused by Lack of Design Basis Control.Placed Procedure 12 Ohp 4030.STP.046 on Administrative Hold ML17325B5471999-04-12012 April 1999 LER 99-009-00:on 990304,as-found RHR Safety Relief Valve Lift Setpoint Greater than TS Limit Occurred.Cause Investigation for Condition Has Not Been Completed.Update to LER Will Be Submitted,Upon Completion of Investigation ML17325B5321999-04-0707 April 1999 LER 99-S01-00:on 990308,discovered That Lock for Vital Gate Leading to Plant 4KV Switchgear Area Was Nonconforming & Vulnerable to Unauthorized Access.Caused by Inadequate Gate Design & Inadequate Procedures.Mods Are Being Made to Gate ML17325B5161999-04-0101 April 1999 LER 99-007-00:on 981020,calculations Showed That Divider Barrier Between Upper & Lower Containment Vols Were Overstressed.Engineers Are Currently Working on Analyses of Loads & Stress on Enclosures ML17325B5221999-03-29029 March 1999 LER 99-001-00:on 960610,degraded Component Cooling Water Flow to Containment Main Steam Line Penetrations,Identified on 990226.Caused by Inadequate Understanding of Design Basis.Additional Investigations Ongoing ML17325B4801999-03-18018 March 1999 LER 99-004-00:on 971030,failure to Perform TS Surveillance Analyses of Rc Chemistry with Fuel Removed Was Noted.Cause of Event Is Under Investigation.Corrected Written Job Order Activities Used to Control SD Chemistry Sampling ML17325B4741999-03-18018 March 1999 LER 99-005-00:on 940512,determined That Rt Breaker Manual Actuations During Rod Drop Testing Were Not Previously Reported.Caused by Lack of Training.Addl Corrective Actions,Including Preventative Actions May Be Developed ML17325B4571999-02-24024 February 1999 LER 99-003-00:on 990107,CR Pressurization Sys Surveillance Test Did Not Test Sys in Normal Operating Condition.Caused by Failure to Recognize Door 12DR-AUX415 as Part of CR Pressure Boundary.Performed Walkdown of Other Doors ML17335A5171999-02-11011 February 1999 LER 99-002-00:on 990112,determined That RCS Pressurizer PORVs Had Not Been Tested,Per Ts.Caused by Inadequate Scheduling Controls Allowing Personnel Error.Surveillance Procedure Was Completed & Updated LER Will Be Submitted ML17335A5141999-02-10010 February 1999 LER 99-001-00:on 990106,noted That GE Hfa Relays Installed in EDGs May Not Meet Seismic Qualification.Caused by Operating Experience Info Incorrectly Dispositioned in 1985. Updated LER Will Be Submitted by 990405 ML17335A5011999-02-0101 February 1999 LER 98-060-00:on 981231,identified That Rt Sys Response Time Testing Did Not Comply with TS Definition.Caused by Inadequate Procedures.Corrective Actions Will Be Developed & Update to LER Will Be Submitted by 990415.With 990201 Ltr ML17335A4951999-01-29029 January 1999 LER 98-059-00:on 981230,interim LER -single Failure in Containment Spray Sys Could Result in Containment Spray Ph Outside Design Occurred.Investigation Into Condition Continuing.Update Will Be Submitted by 990514 Ltr ML17335A4961999-01-27027 January 1999 LER 98-057-00:on 981228,discovered That AFW Valves Were Not Tested IAW Inservice Testing Program.Caused by Failure to Recognize Design Bases Features Re Afws by Personnel. Updated LER Will Be Submittted by 990415.With 990127 Ltr ML17335A4921999-01-19019 January 1999 LER 98-052-01:on 981128,no Analysis for NSR Sc Manual Loader for Tdafwp Could Be Found in Original Design.Cause Due to All Failure Modes Not Considered When Compressed Air Sys Originally Designed.Performed Review of Components ML17335A4721999-01-0606 January 1999 LER 98-055-00:on 981207,potential for Condition Outside of Design Bases for Rod Control Sys Was Noted.Caused by Calibration Error Coupled with Single Rod Failure.Condition Rept Investigation Is Ongoing ML17335A4691999-01-0606 January 1999 LER 98-056-00:on 981211,hot Leg Nozzle Gaps Resulted in Plant Being in Unanalyzed Condition.Analyses Are Being Performed by W to Resolve Problem.Updated LER Will Be Submitted by 990211.With 990106 Ltr ML17335A4661999-01-0505 January 1999 LER 98-049-00:on 981020,emergency Boron Injection Flow Path Was Inoperable.Caused by Original Design Deficiency. Engineering Evaluation of Event Is Continuing ML17335A4631999-01-0404 January 1999 LER 98-054-00:on 981202,discovered That at Least One MSSV Had Not Been Reset as Required by Ts.Engineering Is Continuing Review of Extent of Condition for Event.Updated LER Will Be Submitted by 990129.With 990104 Ltr ML17335A4481998-12-30030 December 1998 LER 98-053-00:on 981130,discovered Use of Inoperable Substitute Subcooling Margin Monitor.Caused by Condition Existing Since Installation of Plant Process Computer in 1992.Updated LER Will Be Submitted.With 981230 Ltr ML17335A4581998-12-28028 December 1998 LER 98-052-00:on 981128,turbine Driven AFW Pump Speed Controller Failure Mode Occurred.Caused Because Not All Failure Modes Were Considered When Compressed Air Sys Was Originally Designed.Verified Current Design Change Process ML17335A4281998-12-22022 December 1998 LER 98-051-00:on 981122,reactor Trip Signal from Manual Safety Injection Not Verified as Required by TS Surveillance,Was Discovered.Maintenance Currently Evaluating Significance & Cause of Event ML17335A4111998-12-17017 December 1998 LER 98-047-00:on 981117,potential for Increase Leakage from Reactor Coolant Pump Seals Was Identified.Util Is Working with W to Resolve Issue.Current Expectations Are to Submit Update to LER by 990215.With 981217 Ltr ML17335A4141998-12-16016 December 1998 LER 98-058-00:on 981216,postulated High Line Break Could Result in Condition Outside Design Bases for AF Occurred. Caused by Deficiencies Associated with Administration of HELB Program.Analysis of AF Will Be Completed by 990122 ML17335A4181998-12-16016 December 1998 LER 98-050-00:on 980814,ancillary Equipment Installed in Ice Condenser Was Not Designed to Withstand Design Basis Accident/Earthquake Loads.Caused by Lack of Established Design Criteria.Developed Design Criteria ML17335A3871998-12-11011 December 1998 LER 98-031-01:on 980610,potential Common Mode Failure of RHR Pumps Were Noted.Caused by Inaccurate Values.Accurate Miniflow Numbers Have Been Determined by Flow Testing ML17335A3821998-12-0808 December 1998 LER 98-039-01 Re EOP Step Conflicts with Small Break LOCA Analysis.Ler 98-039-00 Has Been Canceled.With 981208 Ltr ML17335A3781998-12-0707 December 1998 LER 98-007-00:on 981106,high Energy Line Break Effects in Auxiliary FW Sys Was Noted.Cause of Event Is Under Investigation & Will Be Completed by 990220.Updated LER Will Be Submitted by 990310.With 981207 Ltr ML17335A3771998-12-0303 December 1998 LER 98-046-00:on 981103,determined That Afs Was Unable to Meet Design Flow Requirements During Special Test.Caused by Failure to Consider All Aspects of Sys Operation in Design of Suction Basket Strainers.Sys Will Be Redesigned ML17335A3741998-12-0202 December 1998 LER 97-011-02:on 970822,operation Was Noted Outside Design Bases for ECCS & CSP for Switchover to Recirculation Sump Suction.Caused by Ineffective Change Mgt.Revised Procedure for Switchover 01(02) Ohp 4023.ES-1.3 1999-09-17
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML17335A5641999-10-18018 October 1999 LER 99-024-00:on 990708,literal TS Requirements Were Not Met by Accumlator Valve Surveillance.Caused by Misjudgement Made in Conversion from Initial DC Cook TS to W Std Ts.Submitted License Amend Request.With 991018 Ltr ML17335A5531999-10-0707 October 1999 LER 99-023-00:on 990907,inadequate TS Surveillance Testing of ESW Pump ESF Response Time Noted.Caused by Inadequate Understanding of Plant Design Basis.Surveillance Tests Will Be Revised & Implemented ML17335A5631999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for DC Cook Nuclear Plant,Unit 1.With 991012 Ltr ML17335A5621999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for DC Cook Nuclear Plant,Unit 2.With 991012 Ltr ML17335A5481999-09-30030 September 1999 Non-proprietary DC Cook Nuclear Plant Units 1 & 2 Mods to Containment Sys W SE (Secl 99-076,Rev 3). ML17335A5451999-09-28028 September 1999 Rev 1 to Containment Sump Level Design Condition & Failure Effects Analysis for Potential Draindown Scenarios. ML17326A1291999-09-17017 September 1999 LER 99-022-00:on 990609,electrical Bus Degraded Voltage Setpoints Too Low for Safety Related Loads,Was Discovered. Caused by Lack of Understanding of Design of Plant.No Immediate Corrective Actions Necessary ML17326A1481999-09-17017 September 1999 Independent Review of Control Rod Insertion Following Cold Leg Lbloca,Dc Cook,Units 1 & 2. ML17326A1211999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Cook Nuclear Plant, Unit 2.With 990915 Ltr ML17326A1201999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Cook Nuclear Plant, Unit 1.With 990915 Ltr ML17326A1121999-08-27027 August 1999 LER 99-021-00:on 990728,determined That GL 96-01 Test Requirements Were Not Met in Surveillance Tests.Caused by Failure to Understand Full Extent of GL Requirements. Surveillance Procedures Will Be Revised or Developed ML17326A1011999-08-26026 August 1999 LER 99-020-00:on 990727,EDGs Were Declared Inoperable.Caused by Inadequate Protection of Air Intake,Exhaust & Room Ventilation Structures from Tornado Missile Hazards. Implemented Compensatory Measures in Form of ACs ML17326A0911999-08-16016 August 1999 LER 99-019-00:on 990716,noted Victoreen Containment Hrrms Not Environmentally Qualified to Withstand post-LOCA Conditions.Caused by Inadequate Design Control.Reviewing Options to Support Hrrms Operability in Modes 1-4 ML17326A0771999-08-0404 August 1999 LER 98-029-01:on 980422,noted That Fuel Handling Area Ventilation Sys Was Inoperable.Caused by Original Design Deficiency.Radiological Analysis for Spent Fuel Handling Accidents in Auxiliary Bldg Will Be Redone by 990830 ML17335A5461999-08-0202 August 1999 Rev 0 to Evaluation of Cook Recirculation Sump Level for Reduced Pump Flow Rates. ML17326A0871999-07-31031 July 1999 Monthly Operating Rept for July 1999 for DC Cook Nuclear Plant,Unit 1.With 990812 Ltr ML17326A0861999-07-31031 July 1999 Monthly Operating Rept for July 1999 for DC Cook Nuclear Plant,Units 2.With 990812 Ltr ML17326A0741999-07-29029 July 1999 LER 99-018-00:on 990629,determined That Valve Yokes May Yield Under Combined Stress of Seismic Event & Static,Valve Closed,Stem Thrust.Caused by Inadequate Design of Associated Movs.Operability Determinations Were Performed for Valves ML17326A0661999-07-26026 July 1999 LER 99-017-00:on 990625,noted That Improperly Installed Fuel Oil Return Relief Valve Rendered EDG Inoperable.Caused by Personnel Error.Fuel Oil Return Valve Was Replaced with Valve in Correct Orientation.With 990722 Ltr ML17326A0651999-07-22022 July 1999 LER 98-014-03:on 980310,noted That Response to high-high Containment Pressure Procedure Was Not Consistent with Analysis of Record.Caused by Inadequate Interface with W. FRZ-1 Will Be Revised to Be Consistent with New Analysis ML17326A0491999-07-13013 July 1999 LER 99-016-00:on 990615,TS Requirements for Source Range Neutron Flux Monitors Not Met.Caused by Failure to Understand Design Basis of Plant.Procedures Revised.With 990713 Ltr ML17326A0331999-07-0101 July 1999 LER 99-004-01:on 971030,failure to Perform TS Surveillance Analyses of Reactor Coolant Chemistry with Fuel Removed Was Noted.Caused by Ineffective Mgt of Tss.Chemistry Personnel Have Been Instructed on Requirement to Follow TS as Written ML17326A0511999-06-30030 June 1999 Monthly Operating Rept for June 1999 for DC Cook Nuclear Plant,Unit 2.With 990709 Ltr ML17326A0501999-06-30030 June 1999 Monthly Operating Rept for June 1999 for DC Cook Nuclear Plant,Unit 1.With 990709 Ltr ML17326A0151999-06-18018 June 1999 LER 99-014-00:on 990521,determined That Boron Injection Tank Manway Bolts Were Not Included in ISI Program,Creating Missed Exam for Previous ISI Interval.Caused by Programmatic Weakness.Isi Program & Associated ISI Database Modified ML17325B6421999-06-0101 June 1999 LER 99-013-00:on 990327,safety Injection & Centrifugal Charging Throttle Valve Cavitation During LOCA Could Have Led to ECCS Pump Failure.Caused by Inadequate Original Design Application of Si.Throttle Valves Will Be Developed ML17325B6311999-06-0101 June 1999 LER 99-S03-00:on 990430,vital Area Barrier Degradation Was Noted.Caused by Inadequate Insp & Maint of Vital Area Barrier.Repairs & Mods Were Made to Barriers to Eliminate Degraded & Nonconforming Conditions ML17326A0061999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Dcp.With 990609 Ltr ML17326A0071999-05-31031 May 1999 Monthly Operating Rept for May 1999 for DC Cook Nuclear Plant,Unit 2.With 990609 Ltr ML17325B6351999-05-28028 May 1999 LER 99-S02-00:on 990428,vulnerability in Safeguard Sys That Could Allow Unauthorized Access to Protected Area Was Noted. Caused by Inadequate Original Plant Design.Mods Were Made to Wall Opening to Eliminate Nonconforming Conditions ML17265A8231999-05-24024 May 1999 LER 98-037-01:on 990422,determined That Ice Condenser Bypass Leakage Exceeds Design Basis Limit.Caused by Pressure Seal Required by Revised W Design Not Incorporated Into Aep Design.Numerous Matl Condition Walkdowns & Assessments Made ML17325B6001999-05-20020 May 1999 LER 99-012-00:on 990420,concluded That Auxiliary Bldg ESF Ventilation Sys Not Capable of Maintaining ESF Room Temps post-accident.Caused by Inadequate Control of Sys Design Inputs.Comprehensive Action Plan Being Developed ML17325B5861999-05-10010 May 1999 LER 99-002-00:on 990415,discovered That TS 4.0.5 Requirements Were Not Met Due to Improperly Performed Test. Caused by Incorrect Interpretation of ASME Code.App J Testing Will Be Completed & Procedures Will Be Revised ML17325B5811999-05-0404 May 1999 LER 99-011-00:on 990407,air Sys for EDG Will Not Support Long Operability.Caused by Original Design Error.Temporary Mod to Supply Makeup Air Capability in Modes 5 & 6 Was Prepared ML17325B5771999-05-0303 May 1999 LER 99-010-00:on 990401,RCS Leak Detection Sys Sensitivity Not in Accordance with Design Requirements Occurred.Caused by Inadequate Original Design of Containment Sump Level. Evaluation Will Be Performed to Clearly Define Design ML17335A5301999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for DC Cook Nuclear Plant,Unit 1.With 990508 Ltr ML17335A5291999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for DC Cook Nuclear Plant,Unit 2.With 990508 Ltr ML17325B5581999-04-16016 April 1999 LER 99-006-00:on 990115,personnel Identified Discrepancy Between TS 3.9.7 Impact Energy Limit & Procedure 12 Ohp 4030.STP.046.Caused by Lack of Design Basis Control.Placed Procedure 12 Ohp 4030.STP.046 on Administrative Hold ML17325B5471999-04-12012 April 1999 LER 99-009-00:on 990304,as-found RHR Safety Relief Valve Lift Setpoint Greater than TS Limit Occurred.Cause Investigation for Condition Has Not Been Completed.Update to LER Will Be Submitted,Upon Completion of Investigation ML17325B5321999-04-0707 April 1999 LER 99-S01-00:on 990308,discovered That Lock for Vital Gate Leading to Plant 4KV Switchgear Area Was Nonconforming & Vulnerable to Unauthorized Access.Caused by Inadequate Gate Design & Inadequate Procedures.Mods Are Being Made to Gate ML17325B5161999-04-0101 April 1999 LER 99-007-00:on 981020,calculations Showed That Divider Barrier Between Upper & Lower Containment Vols Were Overstressed.Engineers Are Currently Working on Analyses of Loads & Stress on Enclosures ML17325B5491999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for DC Cook Nuclear Plant Unit 2.With 990408 Ltr ML17325B5441999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for DC Cook Nuclear Plant,Unit 1.With 990408 Ltr ML17325B5221999-03-29029 March 1999 LER 99-001-00:on 960610,degraded Component Cooling Water Flow to Containment Main Steam Line Penetrations,Identified on 990226.Caused by Inadequate Understanding of Design Basis.Additional Investigations Ongoing ML17325B4801999-03-18018 March 1999 LER 99-004-00:on 971030,failure to Perform TS Surveillance Analyses of Rc Chemistry with Fuel Removed Was Noted.Cause of Event Is Under Investigation.Corrected Written Job Order Activities Used to Control SD Chemistry Sampling ML17325B4741999-03-18018 March 1999 LER 99-005-00:on 940512,determined That Rt Breaker Manual Actuations During Rod Drop Testing Were Not Previously Reported.Caused by Lack of Training.Addl Corrective Actions,Including Preventative Actions May Be Developed ML17325B5671999-03-0202 March 1999 Summary of Unit 1 Steam Generator Layup Chemistry from 980101 to 990218. ML17325B4631999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for DC Cook Nuclear Power Station,Unit 2.With 990308 Ltr ML17325B4621999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for DC Cook Nuclear Plant,Unit 1.With 990308 Ltr ML17325B4571999-02-24024 February 1999 LER 99-003-00:on 990107,CR Pressurization Sys Surveillance Test Did Not Test Sys in Normal Operating Condition.Caused by Failure to Recognize Door 12DR-AUX415 as Part of CR Pressure Boundary.Performed Walkdown of Other Doors 1999-09-30
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ACCELERATED D14TRIBUTION DEMONSTRATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)ACCESSION NBR:9111200330 DOC.DATE: 91/11/15 NOTARIZED:
NO FACIL:50-315 Donald C.Cook Nuclear Power Plant, Unit 1, Indiana M AUTH.NAME AUTHOR AFFILIATION BEILMAN,T.P.
Indiana Michigan Power Co.BLIND,A.A.
Indiana Michigan Power Co.RECIP.NAME RECIPIENT AFFILIATION DOCKET 05000315
SUBJECT:
LER 91-007-01:on 910819,shutdown rods mispositioned during attempt to move control rods due to malfunction of multiplexing relay in rod control sys.Multiplexing Relay MXR-1 of Power Cabinet 2AC replaced.W/911115 ltr.DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL L SIZE: TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.NOTES: RECIPIENT ID CODE/NAME PD3-1 LA COLBURN,T-INTERNAL: ACNW AEOD/DS P/TPAB NRR/DET/ECMB 9H NRR/DLPQ/LHFB10 NRR/DOEA/OEAB NRR/DST/SELB 8D LB8D1 REG 02 RGN3 FILE 01 EXTERNAL: EGGG BRYCE,J.H NRC PDR NSIC POORE,W.COPIES LTTR ENCL 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 1 1 1 1 RECIPIENT ID CODE/NAME PD3-1 PD AEOD/DOA AEOD/ROAB/DS P NRR/DET/EMEB 7E NRR/DLPQ/LPEB10 NRR/DREP/PRPBll NRR/DST/SICB8H3 NRR/DST/SRXB 8E RES/DSIR/EIB L ST LOBBY WARD NSIC MURPHY,G.A NUDOCS FULL TXT COPIES LTTR ENCL 1 1 1 1 2 2 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE iVASTE!CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT.20079)TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 31 ENCL 31 Indiana Michigar~Power Company~Cook Vuclear Plant One Cook Place Bridgman, Ml 49106 616 465 5901 November 15, 1991!Ni>54&"4 R~f CH$6RF>>P'O'M'CR United States Nuclear Regulatory Commission Document Control Desk Rockville, Maryland 20852 Operating Licenses DPR-58 Docket No.50-315 Document Control Manager: In accordance with the criteria established by 10 CFR 50.59 entitled Licensee Event Re ort S stem following report is being submitted:
91-007-0l Sincerely, the A.A.Blind Plant Manager AAB:sb Attachment c;D.H.Williams, Jr.A.B.Davis, Region III E.E.Fitzpatrick P.A.Barrett B.F.Henderson R.F.Kroeger B.Walters-Ft.Wayne NRC Resident Inspector T.Colburn-NRC J.G.Keppler M.R.Padgett G.Charnoff, Esq.D.Hahn INPO S.J.Brewer/B.P.Lauzau B.A.Svensson"-cry f i""00330 9 l 1:I<>F.+DOCK 0500v31.>F'DR NRC PDRM366 (669)U.S.NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT ILER)APPROVEO OMB NO.31504)104 E XPIR ES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REOUEST: 60.0 HRS, FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (F630), U.S.NUCLEAR REGULATORY COMMISSION, WASHINGTON.
OC 20555, AND TO THE'APERWORK REDUCTION PROJECT (3)600104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON.
DC 20503.FACILITY NAME (I)DOCKET NUMBER (2)PA E D.C.Cook Nuclear Pl ant-Uni t 1 0 5 0 0 0 3 1 5 1 oF0 3 Shutdown Rods Mispositioned During Attempt To Move Control Rods Due To Malfunction Of Multi lexin Rela In The Rod Control S stem MONTH DAY YEAR YEAR EVENT DATE (5I LER NUMBER (6)SEQUENTIAL NUMBER REPORT DATE (7)YEAR REY0N MONTH OAY NVMBEII DOCKET NUMBER(SI 0 5 0 0 0 FACILITY NAMES OTHER FACILITIES INVOLVED I~)0 819 91 91 007 0'111 15 9 1 0 5 0 0 0 OPERATING MODE (6)POWER LEYEL 1 0 0 8!C.e~0 THE REQUIREMENTS OF 10 CFR (): (Cnectt one or more ol rhe followfnp)
(11 THIS REPORT IS SUBMITTED PURSUANT T 50.73(el(2)(le)50,73(e l(2)(e)50,73(el(2)(rN) 50.73(e I (2)I T)I I)I A I 50.73(el(2)(xlEI(B)50.73(~l(2)(el 20A02(B)20A05(~)(1)(0 20.405(el(II(E I 20A05(el(1)(IIII 20A05 le)(I I (ix)20AOS(el(II(x) 20A05(c)50M(c)(I I 50.36(cl(2)
X 60.73(e)(21(1) 50.73(e)(2)(4) 50.73(e)(2)(IIII LICENSEE CONTACT FOR THIS LER (12I 73.71(B)73.71(c)OTHE R (Specify in AOrrrect Below emf ln yexr, Hf(C Form 366A)NAME T.P.Beilman-Maintenance Superintendant TELEPHONE NUMBER AREA CODE 61 646 5-5901 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)CAUSE SYS'EM COMPONENT MANUFAC TURER EPORTABLE TO NPRDS~%mZ ynr CAUSE SYSTEM COMPONENT MANUFAC.TURER EPORTABLE TO NPRDS E A RLY C34 6 N iI"+VI"eÃ~pj~So.,',II,, x..',$9 Ski"%~a@~;,;,k~'Pg SUPPLEMENTAL REPORT EXPECTED l14)YES llf yN.COmplete EXPECTED SVBEIISSIOIY fJA Ml NO ABSTRACT ILlmfr to te00 rpecer, l.e..epproxlmetely fifteen rinple.recce typewritten liner)(16)EXPECTED SUBMISSION DATE I15)MONTH DAY YEAR This revision provides informaeion on the results of the root cause analysis and corrects the Failed Component Identification information.
On August 19, 1991, during routine surveillance testing of the full length rods, Control Bank A was ordered into the core by the Rod Control System but appeared not to move into the core by observation of the Analog Rod Position Indication.
Further positioning of Control Bank A resulted in an Urgent Alarm being received.Initial troubleshooting of the Rod Control System found no reason for the Urgent Alarm and it was reset.The rods were moved per the test requirements and the surveillance compleeed.
At approximately 1200, a rod misalignment in Shutdown Bank A, Group 2 was suspected due to additional small amount of dilution required to keep thermal power at the pre-surveillance level and a decrease in the Analog Rod Position Indication for Shuedown Bank A, Group 2 in relation to pre-surveillance readings.At 1305 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.965525e-4 months <br /> the flux mapping system was used to determine that the 4 rods of Shutdown Bank A, Group 2 were inserted approximately 6 steps into the core.Further eroubleshooting of the Rod Control System discovered a failure of the 2AC Power Cabinet Multiplexing Relay, MXR-1.It was replaced and proper operation of the Rod Control Syseem was verified.The misaligned rods of Shutdown Bank A were brought out to the top of the core and normal operation resumed at 1605 hours0.0186 days <br />0.446 hours <br />0.00265 weeks <br />6.107025e-4 months <br />.I NRC Form 366 (669)
NRC FORM 366A (6691 U.S.NUCLEAR REGULATORY COMMISSIO LICENSEE EVENT REPORT (LER)TEXT CONTINUATION APPROV E'D OMB NO, 31500104 E XPI R E 6 I 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLl.FCTION REQUESTI 500 HRS.FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH IP-5301.U.S.NUCLEAR AEQUI.ATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PRO4ECT l315001041, OFFICE OF MANAGEMENT AND BUDGET.WASHINGTON, OC 20503.FACILITY NAMK (I)DOCKET NUMBER (21 LER NUMBER (61 PAGE (31 D.C.Cook Nuclear Plant-Unit 1 TEXT///mors sPsssis ssEIIiNd, IIss sdd/0'oIIE/
NRC%%dmI 366A'4/<<2(Y EA R"Q'.6 0 5 0 0 0 315 9]SEQUENTIAL P/'+NUMB E II.<BX 0 0 II 6 V IS I 0 N NUMEEII 01 02 0 3 Conditions Prior to Occurrence Unit One in Mode One at 100 Percent Rated Thermal Power.Descri tion of Event On August 19, 1991, during routine surveillance testing of the full length control rods, Control Bank A was ordered 8 steps into the core by the Rod Control System (EIIS/AA)but appeared not to move into the core by observation of the Analog Rod Position Indication.
Control Bank A was ordered another 2 steps into the core, leaving both group demand counters at 218 steps.The bank was ordered out of the core 4 steps and an Urgent Alarm was received.Further movement of the rods was discontinued pending investigation of the alarm.It was then noticed that Group 2 remained at 218 steps.The shutdown margin was then verified to known plant conditions at the time.Initial troubleshooting of the Rod Control System found no reason for the Urgent Alarm but it was noted that Power Cabinet 2AC (EIIS/AA-JX) vas selecting Shutdown Bank A instead of Control Bank A.As it was presumed to be selected by the control room, the alarm was reset and the rods were moved per the test requirements and the surveillance completed.
Subsequent discussions with control room personnel indicated that no other rod bank had been selected.At approximately 1200, a rod misalignment in Shutdown Bank A, Group 2 was suspected due to additional small amount of dilution required to keep thermal power at the pre-surveillance level and a decrease in the Analog Rod Position Indication for Shutdown Bank A, Group 2 in relation to pre-surveillance readings.At 1305 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.965525e-4 months <br /> the flux mapping system was used to determine that the 4 rods of Shutdown Bank A, Group 2 vere inserted approximately 6 steps into the core and entry into Technical Specification
3.0.3 began
at this time.The flux mapping system was also used to verify.that any other banks involved with Power Cabinet 2AC vere not misaligned, The banks checked were Control Bank A, Control Bank C and also Shutdovn Bank A, Group 1.At 1403 hours0.0162 days <br />0.39 hours <br />0.00232 weeks <br />5.338415e-4 months <br /> reactor power reduction began and an Unusual Event was declared.Further troubleshooting of the Rod Control System discovered a failure of the 2AC Power Cabinet Multiplexing Relay, MXR-1 (EIIS/AA-RLY).
It was replaced and proper operation of the Rod Control System was verified.When tested later on the bench, the relay exhibited fluctuating coil circui,t readings out of the circuit.Notification of the event was made on the ENS at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br />.Each of the misaligned rods of Shutdown Bank A was brought out to the top of the core, one at a time, while verifying that reactivity changes remained within limits.The Unusual Event was terminated at 1605 hours0.0186 days <br />0.446 hours <br />0.00265 weeks <br />6.107025e-4 months <br />.Further research was conducted as to the possibility of the root cause being due to the Stationary B Firing card and/or the Signal Process card.Based on the available information and the satisfactory operating results since the event, the intermittent failure of MXR-1 is believed to be the cause of failure.
NRC FORM 366A (649)u.s.NUCLEAR REGuLATORY COMMISSIO LICENSEE EVENT REPORT (LER)TEXT CONTINUATION APPROVED OMS NO,31504i04 EXPIRES,'4/30/92 tSTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS iNFORMATION COLLECTION REOVEST'00 HRS.FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGtMENT BRANCH IP-530), U.S.NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555.AND TO 1HE PAPERWORK REDUCTION PROJECT 13')504'l04).
OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON.
DC 20503.FACILITY NAME I'I)DOCKET NUMBER (2)YEAR LER NUMBER (6)SEGUENTIAL NUMSEA AEVISION NUMBER PAGE 131 D.C.Cook Nuclear Plant-Unit 1 TEXT///mdip 44444/4/Pi/uiipd, u44 dddicidnu//YRC Fomi 366A3)117) o s o o o 315 91 0 0 7 01 03 OF Cause of Event The rod misalignment was due to failure of the Multiplexing Relay, MXR-1, in Power Cabinet 2AC which allowed Shutdown Bank A, Group 2 to move while Control Bank A was selected.nal sis of Event Technical Specification 3.1.3.4 addresses the situation of only one shutdown rod below the insertion limit of 228 steps (fully withdrawn).
As four shutdown rods were below this limit and required entry into Technical Specification 3.0.3, this event is considered to be reportable pursuant to 10CFR50.73(a)(2)(i)(B) as an operation prohibited by the Plant's Technical Specifications.
Safety consequences of the event were evaluated and determined to be insignificant.
Flux mapping measurements taken prior to the event (August 6, 1991)shows the following:
1)Margin in Heat flux hot channel factor 20.6X 2)Margin in Nuclear enthalpy hot channel factor 7.6X 3)Margin in Allowable power level 9.7X These margins can easily accommodate possible increase in peaking factors due to insertion of shutdown bank A by six steps.Also, a review of the Reload Safety Evaluation indicates an excess shutdown margin of 1817 pcm.This excess offsets any reduction in the shutdown margin due to insertion of Shutdown Bank A by six steps.Corrective Aetio Multiplexing Relay MXR-1 of Power Cabinet 2AC was replaced and proper operation of the Rod Control System was verified.The misaligned rods of Shutdown Bank A were then brought out to the proper position at the top of the core, one at a time.Subsequent use of the control rods to complete planned shutdown activities and routine surveillance testing has been satisfactory with no similar problems occurring.
Faile Co o t d ti atio Unit One Rod Control System, Power Cabinet 2AC, Multiplexing Relay MXR-1 Plant Designation:
2-RCS-2AC, 2A1EZl Manufacturer:
C.P.Clare and Company Model: HG3A-1004 EIIS Code: AA-RLY Previous Similar Events None