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Category:DEFICIENCY REPORTS (PER 10CFR50.55E & PART 21)
MONTHYEARML20217A1691999-09-22022 September 1999 Part 21 Rept Re Engine Sys,Inc Controllers,Manufactured Between Dec 1997 & May 1999,that May Have Questionable Soldering Workmanship.Caused by Inadequate Personnel Training.Sent Rept to All Nuclear Customers ML20205N8341999-04-0101 April 1999 Part 21 Rept Re Automatic Switch Co Nuclear Grade Series X206380 & X206832 Solenoid Valves Ordered Without Lubricants That Were Shipped with Std Lubrication to PECO & Tva.Affected Plants Were Notified ML20236N6751998-07-0909 July 1998 Part 21 & Deficiency Rept Re Notification of Potential Safety Hazard from Breakage of Cast Iron Suction Heads in Apkd Type Pumps.Caused by Migration of Suction Head Journal Sleeve Along Lower End of Pump Shaft.Will Inspect Pumps ML20217D5701998-03-20020 March 1998 Part 21 Rept 40 Re Governor Valve Stems Made of Inconel 718 Matl Which Caused Loss of Governor Control.Control Problems Have Been Traced to Valve Stems Mfg by Bw/Ip.Id of Carbon Spacer Should Be Increased to at Least .5005/.5010 ML20198Q6961998-01-12012 January 1998 Part 21 Rept Re Failed Operation of Agastat EGPI004 Relay on 971129,as Reported by Limerick Station.Caused by Insufficient Soldering.Will Notify Customers Who Purchased EPI004 & ETR14XXX004 Relays During June 1996 LD-97-031, Part 21 Rept Re Incorrect Nut & Washer Plate Matl for ECCS Suction Strainer Bolted Connections.Nut Plates & Washer Plates Fabricated from Incorrect Matl & Delivered to Peach Bottom Unit 3 Site.Nut & Washer Plates Never Installed1997-10-30030 October 1997 Part 21 Rept Re Incorrect Nut & Washer Plate Matl for ECCS Suction Strainer Bolted Connections.Nut Plates & Washer Plates Fabricated from Incorrect Matl & Delivered to Peach Bottom Unit 3 Site.Nut & Washer Plates Never Installed ML20211M6491997-10-0808 October 1997 Addenda 1 to Part 21 Rept Re Weldments on Opposed Piston & Coltec-Pielstick Emergency stand-by Diesel gen-set lube-oil & Jacket Water Piping Sys.Revised List of Potentially Affected Utils to Include Asterisked Utils,Submitted ML20211H7911997-09-30030 September 1997 Part 21 Rept Re Failure of Weldment Associated w/lube-oil Piping Sys on 970804 at Millstone,Unit 2.Root Cause Is Not Yet Known.Quality of Weldment Is Being Considered.Listed Util Sites Affected ML20140A4761997-05-27027 May 1997 Provides Addl Info to 970429 Part 21 Rept Re Potential safety-related Problem W/Asco HV 266000-007J Scram Solenoid Pilot Valves.Corrective Actions Also Listed ML20133E8001997-01-0808 January 1997 Deficiency Rept Re Nonconformance Related to Masterflow 713 Grout,Which Master Builders,Inc Has Supplied as Nuclear SR Product to 18 Npps.Cause Unknown.Requests That Listed Info Be Provided to Gain Insight as to Scope & Possible Cause ML20086T1761995-07-19019 July 1995 Part 21 Rept Re Potential Problem W/Type 51's & 87T Relays. Potential Problem Identified as Defective Tap Block. Recommends That Users Identified on Attachment 1 Page Verify Testing Per Instruction Listed on Encl Product Advisory Ltr ML18038A8971994-09-0707 September 1994 Part 21 Rept Re Defect in Latching Mechanism of Potter & Brumfield Relay on C&D High Voltage Shut Down Alarm Assembly Printed Circuit Boards.Pull Test on Relay Reset Button Incorporated Into Receiving Insp Procedures ML20059H7721994-01-17017 January 1994 Part 21 Rept Re Virginia Power Notifying Fairbands Morse Via Failure Analysis Rept NESML-Q-058 of Defective Air Start Distributor cam,16104412 ML20059F2631994-01-0707 January 1994 Part 21 Rept Re Air Start Distributor Cam Mfg by Fairbanks Morse.Mfg Suggests That Site Referenced in Encl App I Inspect Air Start Distributor Cam as Soon as Practical ML20058G5981993-11-17017 November 1993 Part 21 Rept Re Westronics Recorders,Model 2100C.Signal Input Transition Printed Circuit Board Assembly Redesigned to Improve Recorder Immunity to Electromagnetic Interference.List of Affected Recorders & Locations Encl ML20059L9861993-11-11011 November 1993 Part 21 Rept Re Deviation Wherein Fully Open Butterfly Valve Located 15 Pipe Diameters Upstream of Sensors Was Disturbing Flow Profile Enough to Cause Ultrasonic Meter to Indicate 3 to 4% Low.Customers Notified & Valve Removed ML20125C7161992-12-0707 December 1992 Part 21 Rept Re Possibility for Malfunction of Declutching Mechanisms in SMB/SB-000 & SMB/SB/SBD-00 Actuators. Malfunction Only Occurs During Seismic Event.Balanced Levers May Be Purchased from Vendor.List of Affected Utils Encl ML20127P5861992-11-23023 November 1992 Followup to 921005 Part 21 Rept Re Potential Defect in SB/SBD-1 Housing Cover Screws.Procedure Re Replacement of SBD-1 Spring Cover Bolts Encl.All Fasteners Should Be Loosened & Removed.List of Affected Utils Encl ML20116L5121992-10-0909 October 1992 Part 21 Rept Re safety-related RHR Pump Motor Fan Failure Due to Lack of Weld Penetration Between Fan Blades & Discs. New Duplicate GE Motors Mfg by GE Canada,Motors & Drive Dept.New Surplus Motors Have Double Fillet Welds ML20118B4391992-09-11011 September 1992 Part 21 Rept Re Degradation in Abb Type 27N Undervoltage Relays Used in Electrical Switchgear.Recommends That Users Review Applications Requiring Exposures Greater than 1E03 Rads TID W/Time Delay Function Option ML20090L8801992-03-18018 March 1992 Part 21 Re Cracked Piston Castings Received from Acme Foundry,Fairbanks Morse & General Casting.Magnetic Particle Insp of All Pistons Will Be Performed.List of Affected Plants Encl ML20059M1751990-09-24024 September 1990 Supplemental Part 21 Rept 1 Re Defect in Coltec Industries, Inc Connecting Rod Assemblies Nuts/Bolts on Model 38TD8-1/8 Emergency Generators.Initially Reported on 851120.Nuts/bolts for Assemblies at Stated Plants Inspected & Replaced ML20012A9011990-02-27027 February 1990 Suppls 900213 10CFR21 Rept Re Chilled Water Sys Operation. Evaluation of Crystal River Determined That Postulated High Energy Line Break in Intermediate Bldg May Be Subj to Steam Loads Higher than Normal Loads,Causing Rising Water Temp ML20011F1941990-02-22022 February 1990 Part 21 Rept Re Abb 27/59 Relay Catalog Series 211L.Solder Connections to Printed Wiring Runs on Bottom of Circuit Board Deteriorated Due to Thermal Stress.No Actual Failure Occurred & Relays to Be Changed at Next Outage ML20011F5971990-02-22022 February 1990 Part 21 Rept Re Solder Connections in Abb 27/59 Relays Deteriorated Due to Thermal Stress,Causing Bonding of Printed Wiring Pattern to Glass Epoxy Circuit Board.Interim Circuit Board W/Larger Pads & Higher Wattage Will Be Used ML18153C1011990-02-0202 February 1990 Part 21 Rept Re Two of Three Pc Cards in GE Type SLV11A1 Over/Undervoltage Relays Failing to Produce Output.Short Between Leads Would Result in Damage to Component 1C5. Sketch of Threshold Detection Board Encl ML17223A7451990-01-26026 January 1990 Part 21 Rept Re Backup Rings Furnished in Spare Parts Seal Kits & in 25 Gpm 4 Way Valves as Part of Actuators Made of Incorrect Matl.Rings Should Be Viton & Have Been Identified as Buna N ML20006A7141990-01-19019 January 1990 Updated Final Significant Deficiency Rept 107 Re Defective Agastat GP Relays.Initially Reported on 831129.Use of Subj Relays Does Not Represent Safety Concern & Not Reportable as Operational Concern.Test Program Developed ML20005G6831990-01-0505 January 1990 Part 21 Rept Re Installation Instructions for Grommet Use Range for Patel Conduit Seal P/N 841206.Conduit Seals in Environ Qualification Applications Inspected for Proper Wire Use Range & Grommets Replaced ML19325E0861989-10-16016 October 1989 Followup Part 21 Rept Re Class 1E Battery Chargers W/ Transformers Running at Temps Exceeding Those Used in Qualification Rept When Operating at or Near Full Load Rating of Equipment.Listed Corrective Actions Underway ML19351A2941989-10-0909 October 1989 Part 21 Rept Re Potential of Ambient Compensated Molded Case Circuit Breakers to Deviate from Published Info. Instantaneous Trip Check Will Be Instituted on All Class 1E Thermal/Magnetic Ambient Breakers Prior to Shipment ML19325C9521989-09-29029 September 1989 Part 21 Rept Re Potential Common Failure of SMB-000 & SMB-00 Cam Type Torque Switches Supplied Prior to 1981 & 1976. Vendor Recommends That Switch W/Fiber Spacer Be Replaced ML20248E0121989-09-13013 September 1989 Supplemental Part 21 Rept Re Potential Problem W/Six Specific Engine Control Devices in Air Start,Lube Oil, Jacket Water & Crankcase Sys.Initially Reported on 890429. California Controls Co Will Redesign Valve Seating ML20245G0411989-08-0808 August 1989 Advises That Corrective Actions for Significant Deficiency & Part 21 Rept Re Unqualified Nupro Valve Seals Completed & Resolved,Per 890707 Rept.Only 98 Nupro Test Valves Furnished on GE Racks & Addl 17 Valves Provided for Other Racks ML20246P7111989-07-17017 July 1989 Part 21 Rept Re Quench Cracks in Bar of A-SA-193 Grade B7 Component.Quench Cracks Found in One Bar of Matl.Listed Purchasers Informed of Potential Defect.Next Rept Will Be Submitted When Addl Info Becomes Available ML20247D3011989-07-12012 July 1989 Part 21 Rept 10CFR21-0047 Re Control Wiring Insulation of Inner Jacket Used on General Motors Diesel Generator Sets Identified as 999 or MP Series.Encl List of Owners of Units Notified ML20246J6411989-07-0707 July 1989 Supplemental Part 21 & Deficiency Rept L2-89-44 Re Nupro Test Valves,Installed on Instrument Line Racks Furnished by Ge,Not Remaining Leak Tight During DBA Conditions.Initially Reported on 890608.Root Cause Analysis Will Be Performed ML20245K9061989-06-30030 June 1989 Significant Deficiency Repts L2-89-08,38,43 & 45-48 Re Safe Shutdown Analysis.Corrective Actions Completed & Significant Deficiencies Considered Resolved ML20245B6651989-06-15015 June 1989 Part 21 Rept 150 Re Potential Defect in Component of Dsr Standby Diesel Generator.Cause of Failure Determined to Be Combination of Insufficient Lubrication to Bushings.Listed Course of Action Recommended at Next Scheduled Engine Maint ML20244A5101989-06-0707 June 1989 Final Significant Deficiency Rept SDR-L2-89-39 Re Failure of Stainless Steel Midlock Ferrules.Caused by Isolated Stress Corrosion Cracking Not Affecting Other Penetration Ferrules in Penetration 20JX222 Replaced ML20247N7731989-05-31031 May 1989 Supplemental Significant Deficiency Rept Re Safe Shutdown Analysis self-assessment ML20247Q7341989-05-31031 May 1989 Significant Deficiency Rept L2-89-34 Re Tavis Pressure Differential Transmitters Installed W/O Connecting Internal Heaters.Initially Reported on 890418.Heaters Will Be Connected on All Tavis Pressure Differential Transmitters ML20246F9051989-05-15015 May 1989 Significant Deficiency Rept L2-89-23 Re Essential Equipment Located in Unanalyzed Environ.Installation of Conduit Seals or Reorientation of Conduit Runs Planned to Avoid Moisture Intrusion Into Electrical Equipment Prior to Startup ML20246M3681989-05-0808 May 1989 Significant Deficiency Rept L2-89-06 Re Unavailability of Suppression Pool Indication Due to App R Fire.Caused by Design Error Resulting from Lack of Procedural Guidance. Reportability Evaluation Initiated ML20246K7401989-04-26026 April 1989 Part 21 Rept Re Incorrectly Stamped Name Plates on Certain Asco Nuclear Qualified Valves.Vendor Will Contact Each Affected Facility & Furnish Correctly Stamped Plates & in Near Future Discontinue Sale of Rebuild Kits for Valves ML20248F6101989-04-13013 April 1989 Interim Significant Deficiency Rept L2-88-11 Re Inadequate Degraded Grid Undervoltage Relay Setpoints.Event Discussed W/Engineer Involved to Ensure Procedural Adherence & New Undervoltage Relays Will Be Installed ML20244D8161989-04-13013 April 1989 Part 21 Rept Re Failure of Rosemount Transmitters.All Failed Transmitters Replaced,Inservice Test Procedure Prepared & Monthly Test of All 12 Transmitters in RCS Throughout Cycle 2 Operation Will Be Performed.Review Continuing ML20247P7991989-04-0404 April 1989 Part 21 Rept Re Atmospheric Dump Valves.Cause of Failure Speculative But Result of Piston Ring That Failed to Seal. Resolution to Problem Requires Increasing Pilot Valve Capacity & Reworking of Plug to Enlarge Pilot Flow Area ML20248F3571989-04-0303 April 1989 Interim Significant Deficiency Rept SDR-L2-89-17 Re Unavailability of Feedwater Maint Isolation Valve to Support RCIC Operation in Event of App R Fire.Initially Reported on 890303.Cause Under Investigation.Rept to Be Submitted ML20248F9451989-03-28028 March 1989 Part 21 Rept Re Replacement of Circuit Boards for Safeguard Battery Chargers.Initially Reported on 890323.C&D Power Sys Provided Instructions to Change Out 600 Ohm Fixed Resistor w/500 Ohm Variable Resistor in Charger Circuitry 1999-09-22
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217K9931999-10-14014 October 1999 Safety Evaluation Supporting Amend 234 to License DPR-56 ML20217B4331999-10-0505 October 1999 Safety Evaluation Supporting Amend 233 to License DPR-56 ML20217D1211999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Lgs,Units 1 & 2. with ML20217G3541999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Pbaps,Units 2 & 3. with ML20216H7091999-09-24024 September 1999 Safety Evaluation Supporting Amends 229 & 232 to Licenses DPR-44 & DPR-56,respectively ML20217A1691999-09-22022 September 1999 Part 21 Rept Re Engine Sys,Inc Controllers,Manufactured Between Dec 1997 & May 1999,that May Have Questionable Soldering Workmanship.Caused by Inadequate Personnel Training.Sent Rept to All Nuclear Customers ML20212D1281999-09-17017 September 1999 Safety Evaluation Supporting Proposed Alternatives CRR-03, 05,08,09,10 & 11 ML20212A8861999-09-13013 September 1999 Safety Evaluation Authorizing First & Second 10 Yr Interval Inservice Insp Plan Requestss for Relief RR-01 ML20212A4481999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Limerick Generating Station,Units 1 & 2.With ML20212A5871999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Peach Bottom,Units 2 & 3.With ML20211D5501999-08-23023 August 1999 Safety Evaluation Supporting Amends 228 & 231 to Licenses DPR-44 & DPR-56,respectively ML20211E9891999-08-20020 August 1999 LGS Unit 2 Summary Rept for 970228 to 990525 Periodic ISI Rept Number 5 ML20212H6311999-08-19019 August 1999 Rev 2 to PECO-COLR-P2C13, COLR for Pbaps,Unit 2,Reload 12 Cycle 13 ML20210L7051999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Limerick Generating Station,Units 1 & 2.With ML20210N7641999-07-31031 July 1999 Monthly Operating Repts for Jul 1999 for PBAPS Units 2 & 3. with ML20209G0211999-06-30030 June 1999 GE-NE-B13-02010-33NP, Evaluation of Limerick Unit 2 Shroud Cracking for at Least One Fuel Cycle of Operation ML20209H1121999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Pbaps,Units 2 & 3. with ML20209D7741999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Limerick Generating Station,Units 1 & 2 ML20195G4651999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Lgs,Units 1 & 2 ML20195H8841999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Pbaps,Units 2 & 3. with ML20207H8331999-05-31031 May 1999 Non-proprietary Rev 0 to 1H61R, LGS - Unit 2 Core Shroud Ultrasonic Exam ML20209D7791999-05-31031 May 1999 Revised Monthly Operating Repts for May 1999 for Limerick Generating Station,Units 1 & 2 ML20195B3021999-05-0606 May 1999 Rev 0 to PECO-COLR-L2R5, COLR for Lgs,Unit 2 Reload 5 Cycle 6 ML20195G4761999-04-30030 April 1999 Revised Monthly Operating Repts for Apr 1999 for Lgs,Units 1 & 2 ML20206N2901999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Limerick Generating Station,Units 1 & 2.With ML20206N1661999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Pbaps,Units 2 & 3. with ML20206D8971999-04-22022 April 1999 Rev 2 to PECO-COLR-L1R7, COLR for Lgs,Unit 2 Reload 7, Cycle 8 ML20206A2921999-04-20020 April 1999 Safety Evaluation Concluding That Proposed Changes to EALs for PBAPS Are Consistent with Guidance in NUMARC/NESP-007 & Identified Deviations Meet Requirements of 10CFR50.47(b)(4) & App E to 10CFR50 ML20205K7411999-04-0707 April 1999 Safety Evaluation Supporting Amends 227 & 230 to Licenses DPR-44 & DPR-56,respectively ML20205N8341999-04-0101 April 1999 Part 21 Rept Re Automatic Switch Co Nuclear Grade Series X206380 & X206832 Solenoid Valves Ordered Without Lubricants That Were Shipped with Std Lubrication to PECO & Tva.Affected Plants Were Notified ML20205N9311999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Limerick Generating Station,Units 1 & 2.With ML20205P5851999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Peach Bottom Units 2 & 3.With ML20204G9851999-03-11011 March 1999 Safety Evaluation Re Revised Emergency Action Levels for Limerick Generating Station,Units 1 & 2 ML20207J7461999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Limerick,Units 1 & 2.With ML20207G9971999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Peach Bottom Units 2 & 3.With ML20199G2371999-01-31031 January 1999 Rev 0 to NEDO-32645, Limerick Generating Station,Units 1 & 2 SRV Setpoint Tolerance Relaxation Licensing Rept ML20199L5301999-01-19019 January 1999 Special Rept:On 981214,seismic Monitor Was Declared Inoperable.Caused by Spectral Analyzer Not Running.Attempted to Reboot Sys & Then Sent Spectral Analyzer to Vendor for Analysis & Rework.Upgraded Sys Will Be Operable by 990331 B110078, Rev 1 to GE-NE-B1100786-01, Surveillance Specimen Program Evaluation for Limerick Generating Station,Unit 11998-12-31031 December 1998 Rev 1 to GE-NE-B1100786-01, Surveillance Specimen Program Evaluation for Limerick Generating Station,Unit 1 ML20199F9611998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Limerick Generating Station.With ML20206P1651998-12-31031 December 1998 Fire Protection for Operating Nuclear Power Plants, Section Iii.F, Automatic Fire Detection ML20205K0381998-12-31031 December 1998 PECO Energy 1998 Annual Rept. with ML20206D3591998-12-31031 December 1998 1998 PBAPS Annual 10CFR72.48 Rept. with ML20206D3651998-12-31031 December 1998 1998 PBAPS Annual 10CFR50.59 & Commitment Rev Rept. with ML20199E3471998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Peach Bottom,Units 1 & 2.With ML20198A3871998-12-10010 December 1998 Safety Evaluation Supporting Licensee Response to GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power- Operated Gate Valves ML20198C7151998-12-10010 December 1998 Rev 1 to COLR for LGS Unit 1,Reload 7,Cycle 8 ML20196G7021998-12-0202 December 1998 SER Authorizing Proposed Alternative to Delay Exam of Reactor Pressure Vessel Shell Circumferential Welds by Two Operating Cycles ML20206N4061998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Limerick Generating Station,Units 1 & 2.With ML20196E8261998-11-30030 November 1998 Response to NRC RAI Re Reactor Pressure Vessel Structural Integrity at Peach Bottom Units 2 & 3 ML20198B8591998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Pbaps,Units 2 & 3. with 1999-09-30
[Table view] |
Text
_ _ _ . __ ____ --__ _ ____-__-______
WMD CORRESitNDENC4 h
h . PHILADELPHIA ELECTRIC COM ANY sy
- c. y 0
2301 MARKET STREET b ~ - :9 ,2O d .
P.O. BOX 8699 M :p ,
i PHILADELPHIA. PA.191o1 f f
SHIELDS L. DALTROFF i '; vI g auM.U"otE June 16, 1986' , '
Re: Docket Nos. 50-277 gb 50-278 50-35 [ D o C Dr. Thomas E. Murley, Administrator Region I U. S. Nuclear Regulatory Commission 631 Park Avenue "
King of Prussia, PA 19406
Subject:
Peach Bottom Atomic Power Station Units 2 and 3 Limerick Generating Station Unit 1 Reactor Protection System Power Supply Circuit Breakers 10 CFR Part 21 Report
Dear Dr. Murley:
In accordance with 10 CFR Section 21.21(b)(3), the following information is being provided regarding recent failures of the shunt trip coils on the Westinghouse circuit breakers in the reactor protection system (RPS) under operating reactor licenses for Peach Bottom Atomic Power Station (Peach Bottom) and Limerick Generating Station (Limerick)
- 1. Name of individuals informing the Commission: Oral notification was made to R. M. Gallo, U.S. NRC, on '
June 9,1986, by tihe following individuals: '
G. M. Leitch R. H. Logue
- 2. Identification of basic component which contains a defect:
Westinghouse Type LBB Circuit Breakers
- Catalog Number LBB 22250 2-pole,.400 Amp, magnetic trip only, with 125 VDC shunt trip and .
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i 8607230277 DR 860616 ADOCK 05000277 PDR YJ_. , _ . ._. .-_ _n_____.__.. _ -
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Dr. Thomas E. Murley Page 2 D k
to 2250 Amps. :
d
- 3. Identification of firm supplying the basic component: 9 Westinghouse Electric Corporation (
- 4. Nature of defect and the safety hazard which could h be created j On one occasion at Limerick and several ;I v
instances at Peach Bottom, the shunt trip coils of the reactor protection system (RPS) power supply breakers were found to be damaged after apparent normal operation of the (,
breakers. An investigation into this matter <
has, determined that the failures were in all likelihood caused by the combination of misoperation of the breaker in the presence of a minor manufacturing defect.
After a successful trip of the breaker, the i shunt trip coil can be damaged if attempts are -
made to reclose the breaker with a trip signal present. This damage will occur provided that g the breaker also has a manufacturing defect
- known as " insufficient spin-over." The spin- (
over process is performed to remove excess metal from the bott'om of a rivet on the breaker handle post. The presence of the extra metal can cause binding between the breaker handle post and breaker operating mechanism. Attempts to close an unaffected breaker with a trip signal still present :
apparently does not cause damage to the shunt :
trip coils. c The power supply circuits served by the RPS j' circuit breakers are provid4d with relay protection against undervoltage, overvoltage and underfrequency. Any one of these abnormal conditions in the power supply will cause the shunt trip coil to actuate causing the breaker to open. For each of the two normal RPS busses for Peach Bottom Units 2 & 3 there are two of these circuit breakers in series. !
Additionally, Peach Bottom utilizes an l alternate RPS power supply on each unit which j contains two of these breakers in series. ;
Limerick utilizes two of these breakers in s :
l l
l l
l l
N -
e Dr. Thomas E. Murley Page 3 series in each of the two RPS power supplies. ,
These breakers and their associated protective !
1 relays are designed to prevent abnormal j conditions in the power supply from damaging 1 or making the RPS equipment inoperable. j 1
Upon loss of power or upon opening of these circuit breakers, the RPS will deenergize and initiate a scram signal. If one of the two series breakers in one of the two RPS power supplies opens, a half-scram signal is generated. If one breaker in both of the RPS power supplies opens, a full reactor scram will be initiated.
The following sequence of events and ,
conditions provides a mechanism for common ,
i mode failure of these shunt trip coils. l i I o Following operation of the circuit )
i breaker (either after testing or j l required actuation from abnormal ;
power supply conditions), plant personnel attempt to reset the ,
4 breaker with the trip signal from I the relays still present. This is contrary to normal practice. ,
l o The handle is pushed to reset and j then to the closed position.
o Excess metal on the bottom of a i rivet on the breaker handle post
! causes binding between the handle i and the breaker operating mechanism.
4 This binding does not prevent the ;
l main contacts from opening. :
- o The binding prevents the 'a' contact l of ghe auxiliary cutoff switch in
',', l ser1es with the shunt trip coil from i opening and current passes through l I , the shunt trip coil (which is l
! designed to be a momentarily l
energized coil) until it fails. ,
o The failed shunt trip coil is not detected and the breaker is l subsequently successfully reset.
'o The breaker is now back in service l without the capability to trip for l undervoltage, overvoltage or under i i ~ frequency protection of the RPS , I
) power supply. .
V ;
j l
l l
I
_. - --. = ___A
Dr. Thomas E. Murley Page 4 Operation with a degraded power supply on the RPS system has the potential to prevent a successful scram. However, this could only occur if all of the following conditions occurred.
o Both shunt coils on the breakers of one RPS supply had failed open.
o An extended degraded power supply condition exists on that RPS bus.
o The RPS equipment being supplied the degraded power supply, failed to operate properly with the off normal condition.
o A valid RPS signal was present.
The probability of all of these conditions occuring simultaneously, considering the monitoring frequency discussed in Section 7, is felt to be remote.
- 5. Date on which the information of such a defect was obtained:
Failures of these breakers occurred at Peach Bottom on April 11, 1985; January 16, 1986; January 27, 1986; February 8, 1986 and April 23, 1986. The failure at Limerick occurred on November 9, 1984. The evaluation to determine reportability of this defect was completed on June 9, 1986.
- 6. The number and location of the basic component that contains a defect:
Twelve breake,rs of this type breakers are ,
utilized on Peach Bottom Units 2 and 3. They are arranged such that there are two breakers in series for each of the two normal RPS power supplies for each unit and two breakers in series in the single alternate RPS power supply.
The breakers are designated on each unit as follows: .
A=52-AC757A B=52-BC757B A Alt.=52-CC757A C=52-AC757C D=52-BC757D B Alt.=52-CC757B
\
~
_ - - __. ~ n i
Dr. Thomas E. Murley Page 5 Four breakers of this type are utilized on -
Limerick Unit 1. They are arranged such that there are two breakers in series for each of the two RPS power supplies on Unit 1. They are designated as follows:
A=52-AY24801 B=52-BY24801 C=52-CY24801 D=52-DY24801
- 7. Corrective action that has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action:
Steps have been taken at both Peach Bottom and Limerick to preclude future failures of this type. Operation aids (labels) have been affixed at the appropriate breakers instructing the operators to assure that tr'ip signals are not present when attempting to close the breakers.
The four Limerick Unit 1 RPS power supply breakers have been replaced with new breakers as of June 6, 1986. Utilizing a test procedure provided by Westinahouse, each of the replacement breakers was tested to determine if the breakers had a similar spin-over binding problem. The four installed breakers successfully passed this test procedure.
Additional modifications as described below have been made to the breaker shunt trip circuitry at Limerick and will be performed at Peach Bottom.,, ,
A circuit interlock was added to each of the RPS breaker shunt trip circuits. This interlock consists of wiring the second unused main contact of each breaker in series with its shunt trip coil and 'a' contact. The additional interlock contact will open the shunt trip coil circuit whenever the breaker i is opened or tripped, assuring that the shunt :
trip coil is not energized beyond its momentary rating.
l y -- - , - -
w _ , - _ _ . _q ,,ee _, ,-- - - --------g r,p- v, , m --g y--- - - - - - - --
Dr. Thomas E. Murley Page 6 The neon indicating lamps which are used to determine if a shunt trip signal is present will be replaced with multi-light emitting diode lamps during the first refueling outage currently scheduled for April 1987. These lamps have better visibility and, the'refore, will make it easier to determine if the trip signal is present.
These modifications will be installed on the Peach Bottom Unit 2 RPS power supply breakers during the next refueling outage scheduled for March 1987. The modifications to the Unit 3 breakers will be performed during the mid-cycle surveillance outage currently scheduled for January, 1987. ,
Until such time that the modifications are completed on Peach Bottom Unit 2 and 3,.
surveillance test ST 13.54 "M/G Set Breaker Coil Continuity Check" will be performed weekly and following any RPS breaker e operation. The purpose of this test is to check the continuity of the RPS breakers in order to verify that the shunt trip coil and
'a' contact are intact to ensure the operability of the breakers.
Since the circuit breaker interlock modifications have been completed at Limerick, this frequency of testing the breakers has been discontinued at Limerick. The surveillance interval will be returned to the Technical Specification requirement of once per 18 months.
Westinghouse has advised us that they are '
revising the Breaker manufacturing drawings to change the amount of spin-over on the handle post. They are also testing these breakers with the operating handle in the closed position to ensure that binding, which could cause shunt trip coil failures in this adverse operating condition, does not exist.
- 8. Notification: I 1
The industry was notified of these failures )
via an entry on INPO's NUCLEAR NETWORK on June 10, 1986.
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_D an A - - - - - a ms N._ ,_ A
Dr. Thomas E. Murley Page 7 If you have any questions or require additional information, please do not hesitate to contact us.
Very truly yours,
( 1, ~ ~ ~~
cc: Director, Office of Inspection & Enforcement (3)
E. M. Kelly, LGS Senior Resident Site Inspector T. P. Johnson, PB Resident Site Inspector See Attached Service List e
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cc: Troy B. Conner, Jr., Esq.
Ann P. Hodgdon, Esq.
Mr. Frank R. Romano l Mr. Robert L. Anthony j Ms. Phyllis Zitzer Charles W. Elliott, Esq.
Barry M. Hartman, Esq.
Mr. Thomas Gerusky Director, Penna. Emergency Management Agency Angus Love, Esq.
David Wersan, Esq.
Robert J. Sugarman, Esq.
Kathryn S. Lewis, Esq.
Spence W. Perry, Esq.
Atomic Safety & Licensing Appeal Board Atomic Safety & Licensing Board Panel Docket & Service Section (3 Copies) l E. M. Kelly l Timothy R. S. Campbell l
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1 February 4, 1986 i
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