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| | number = ML17221A601 | | | number = ML17221A601 |
| | issue date = 01/29/1988 | | | issue date = 01/29/1988 |
| | title = LER 87-007-01:on 871125,Reactor Tripped on Loss of Load Due to Turbine Trip.Caused by Personnel Error.Permanent Magnet Generator & Exciter Bearing Replaced & Exciter Bearing Thermocouple Removed.W/880129 Ltr | | | title = LER 87-007-01:on 871125,reactor Tripped on Loss of Load Due to Turbine Trip.Caused by Personnel Error.Permanent Magnet Generator & Exciter Bearing Replaced & Exciter Bearing Thermocouple removed.W/880129 Ltr |
| | author name = JOHNSON A B, WOODY C O | | | author name = Johnson A, Woody C |
| | author affiliation = FLORIDA POWER & LIGHT CO. | | | author affiliation = FLORIDA POWER & LIGHT CO. |
| | addressee name = | | | addressee name = |
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| | page count = 6 | | | page count = 6 |
| }} | | }} |
| | |
| | =Text= |
| | {{#Wiki_filter:REGULA,Y INFORMATION DISTR I BUT I YSTEM ( R IDS ) |
| | ACCESSION NBR: 8802020148 DOC. DATE: 88/01/29 NOTARIZED: NO DOCKET ¹ FACIL: 50-389 St. Lucie Plant> Unit 2> Florida Poeer 5 Light Co. 05000389 AUTH. NAME AUTHOR AFFILlATION JOHNSON'. B. Fl or i da Poeer 5 Light Co. |
| | WOODY. C. O. Florida Power 5 Light Co. |
| | REC IP. NAME RECIPIENT AFFILIATION |
| | |
| | ==SUBJECT:== |
| | LER 87-007-01: on 871125. reactor tripped on loss of load due to turbine trip. Caused bg personnel error. Permanent magnet generator 5 exciter bearing replaced Zc exciter bearing thermocouple removed. W/880129 ltr. |
| | DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ENCL SIZE: |
| | TITLE: 50. 73 Licensee Event Report (LER) i Incident Rpti etc. |
| | NOTES: |
| | REC IP IENT COPIES REC IP IENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 TOURIGNYi E 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/NAS 1 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 ARM/DCTS/DAB 1 DEDRO 1 1 NRR/DEST/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 NRR/DEST/ICSB 1 1 NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 1 NRR/DEST/SGB 1 NRR/DLPG/HFB 1 NRR/DLPG/GAB 1 1 NRR/DOEA/E*B 1 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 A)R /SIB 1 1 NRR/PMAS/ILRB 1 1 REG FILE 02 1 1 RES TELFORDi J 1 1 IB 1 1 RES/DRPS DIR 1 1 RGN2 FILE 01 1 1 EXTERNAL: EG5G GROHi M 5 5 FORD BLDG HOY> A 1 H ST LOBBY WARD 1 1 LPDR" 1 1 NRC PDR 1 1 NSIC HARRIS> J 1 1 NSIC MAYST G 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 46 ENCL 45 |
| | |
| | NRC Form 3SSA U.S, NUCLEAR REGULATORY COMMISSION 19413 l LICENSEE ENT REPORT (LER) TEXT CONTINUA ION APPROVED OMB NO. 3150&104 EXPIRES: 9/31/BB FACILITY NAME III OOCKET NUMBER Ill LER NUMBER IBI PAGE 0) |
| | St. Lucie, Unit 2 YEAR @~a. |
| | NvM Err xo,: REvrsroN SFOVENT/AL iM NVM Ell o s o o o 3 89 '87 007 0 1 0 2 OF 0 4 TEXT /ifmoro s/rsco is rsr/rr/rsd, rrso sddio'orrs/ H/IC Fonrr 3////A'/ (IT) |
| | DESCRIPTION OF ENTENTE On 25 November, 1987, St. Lucie Unit Two was operating at 50 percent power steady state in Mode 1. The unit was returned to service on 23 November following a refueling outage and was holding at 50 percent power while repairs were in progress on the 2A Steam Generator Feed Pump (SGFP) (EIIS:SJ) due to a small water leak that developed on the vent line at the pump casing. The reactor was being maintained in a steady state condition with all automatic controllers placed in automatic with the exception of the Control Rod Drive System (EIZS:JD) which was in OFF. |
| | At 2331 hours, the Reactor Protective System (EIZS:JC) initiated a reactor trip on loss of load due to a turbine trip. The turbine tripped on a main generator (EIIS:TB) lockout. The control room was alerted with information that smoke was seen coming out of the Main Generator Exciter (EZIS:TL). The Assistant Nuclear Plant Supervisor (ANPS) instructed the Turbine Operator (TO) to check for rubs on the rotating components of the turbine-generator. The TO reported evidence of turbine-generator rubs to the control room and the ANPS instructed the Reactor Control Room Operators (RCOs) to open the vacuum breakers on the main condenser (EIZS:SG) to aid in slowing down the turbine. |
| | A fire team was assembled and stationed with fire fighting equipment at the vicinity of the main generator exciter. There were no reports of an actual fire. |
| | The trip was an uncomplicated trip and all systems functioned normally. The Steam Bypass Control System (SBCS) (EIIS:JI) operated to reduce primary average temperature (T-avg) to the zero percent power setpoint of 532 degrees F. Auxiliary feedwater (EIZS:BA) was initiated manually to control the steam generator (S/G) level for Reactor Coolant System (RCS) (EIZSEAB) heat removal. The standard post trip actions were completed and the unit was immediately stabilized in Hot Standby, Mode 3. |
| | NRC FORM 316A 19831 |
| | |
| | NRC Form 3ddA V.S. NUCLEAR REGULATORY COMMISSION (983) |
| | LICENSE ENT REPORT (LER) TEXT CONTINU ON APPROVEO OMS NO. 3150MI(H EXP!RES: 8/3(188 FACILITY NAME (I) DOCKET NUMBER (3) LER NVMSER (8) PACE (3) |
| | SEQUENTIAL REVISION YEAR @g NUM tR NUM ER St. Lucie, Unit 2 o s o o o 0 0 7 0 1 0 3 OF 0 4 TERT (Ilmoro <<>>oo b ror)rrr'rod, Ir>> odds'onel NRC Farm 3ddl3 I ()T) |
| | CAUSE OF TBB EVENTS The immediate cause of the main generator lockout was loss of the generator field. The loss of field was caused by destruction of the exciter Permanent Magnet Generator (PMG) that occurred when the exciter bearing failed allowing the PMG armature to rub on the PMG stator. |
| | Further investigation into the failure of the exciter bearing indicated that a ground was caused by a completed electrical circuit between the exciter bearing and the exciter base. This completed electrical circuit bypassed the insulation between the bearing pedestal and the exciter base. The ground was caused by an improper installation of an instrument cable (EIIS:IT). The instrument cable provides the terminal connection from the thermocouple of the N9 exciter bearing housing to its terminal box, which provides remote temperature indication in the control room. The as-found condition of the instrument cable indicated that the braided wire cable shield was not properly positioned in the clamp; therefore, a ground developed at the exciter bearing. Examination of the exciter bearing revealed pitting marks on the bearing surface, characteristic of current flowing across the bearing journal to the bearing pad, which resulted in the bearing failure. |
| | The improper arrangement of the instrument cable cannot be conclusively identified as a wiring error during the installation of the new main generator exciter. |
| | The PMG and the instrument cable were meggered to detect for possible grounds and the results were acceptable. It has been postulated that one of two circumstances may have occurred: 1) the instrument cable was installed correctly with the braided wire shield in the clamp when it was meggered; then at some later date, the instrument cable was accidently stepped on causing the cable shield to become separated from the clamp; or 2) the instrument cable, being clamped incorrectly to the pedestal, had not yet been connected to the terminal box when the megger test was performed. |
| | After placing the main generator back in service, the ground should have been detected during the performance of the weekly generator exciter ground check. |
| | The preventative maintenance Plant Work Order (PWO) requires voltages to be read across the N9 bearing shaft to ground and across the 59 bearing pedestal to ground. The data is to be evaluated to ensure no grounds have developed in the main generator exciter. Early recognition of the ground would have prompted immediate action to remove the main generator from service for the necessary repairs. |
| | The root cause of the event was a cognitive personnel error by a utility main-tenance supervisor in misinterpretation of the main generator exciter ground voltage readings. The appropriate procedure was properly followed. However, lack of understanding of the significance of the generator exciter ground check and inadequate acceptance criteria in the PWO were contributing factors in the personnel error. There were no unusual characteristics of the work location that directly contributed to the personnel error. |
| | NRC fORM 3ddA (983) |
| | |
| | URC Form 366A U.S. NVCLEAR RECULATORY COMMISSION (983) |
| | LICENSEE NT REPORT (LER) TEXT CONTINUA ON APPROVED OMB NO. 3150WIOi EXPIRES: 8/31/88 FACILITY NAME (11 DOCKET NUMBER (2) LER NUMBER (6) PACE (3) |
| | YEAR SEOUENTIAL REVISION NUMBER NUM Ell St. Lucie, Unit 2 p 5 p p p 3 8 9 8 7 0 0 7 0 1 0 4 OF 0 4 TEXT /I/mort t/Mcoit ror)rr/rtd. Ihto tdChr/ont/HRC Forrrr 36(L('ti (17) |
| | ANALYSIS OF THE EVENT: |
| | The event is reportable under 10 CFR 50.73 (a)(2)(iv), "any event or condition that resulted in manual or automatic actuation of any Engineered Safety Feature, including the Reactor Protection System." |
| | This event was observed to be a routine reactor trip on loss of load. The resulting transient was well enveloped by the St. Lucie Unit II2 Final Updated Safety Analysis Report section 15.2.1.2 "Limiting Reactor Coolant System Pressure Event-Isolation of Turbine (100% power)." All Plant Safety Functions were met and there were no additional complications. Consequently, the health and safety of the public were not affected by this event. |
| | CORRECTIVE ACTIONS. |
| | : 1. The Permanent Magnet Generator was replaced. |
| | : 2. The Exciter Bearing was replaced. |
| | : 3. An evaluation was made and'the Exciter Bearing thermocouple was determined to be unnecessary type. |
| | and it was removed to prevent future incidents of this |
| | : 4. The preventative maintenance plant work order was revised to adequately define the acceptance criteria and the proper actions when the acceptance criteria are not met. |
| | : 5. Training was given to all Electrical Maintenance personnel to elaborate on the importance of properly evaluating the data during performance of the weekly generator exciter ground check. h |
| | : 6. The plant training group will evaluate this item to determine appropriate training requirements and methods. |
| | ADDITIONAL INFORMATION: |
| | FAILED COMPONENT INFORMATION: |
| | Westinghouse Exciter Bearing (89 bearing) |
| | Part I)613F432 GOl PREVIOUS SIMILAR EVENTS: |
| | See LER 5389-84-011 for a previous reactor trip due to exciter bearing failure. |
| | NRC FORM 366* |
| | (983) |
| | |
| | P. O. 14000, JUNO BEACH, FL 33408.0420 SKNLI5 2 9 1988 L-88-41 10 CFR 50,73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 |
| | , Gentlemen: |
| | Re: St. Lucie Unit 2 Docket No. 50-389 Reportable Event: 87-07 Revision 1 Date of Event: November 25, 1987 Reactor Trip on Loss of Load Caused by Main Generator Exciter Bearin Failure Due to Personnel Error The attached Licensee Event Report (LER) is being submitted pursuant to the requirements of 10 CFR 50.73 to provide an update on the subject event. |
| | Very truly yours, C. 0. ody Executive Vice President COW/GRM/gp Attachment cc: Dr. J. Nelson Grace, Regional Administrator, Region ZI, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant GRM/022.LER an FPL Group company}} |
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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML17241A4891999-10-0707 October 1999 LER 99-004-00:on 990912,noted That MSSV Surveillance Was Outside of TS Requirements.Caused by Setpoint Drift.Subject MSSVs Are Being Refurbished & Retested Prior to Unit Startup from SL1-16 Refueling Outage.With 991007 Ltr ML17241A4111999-07-16016 July 1999 LER 99-007-00:on 990610,unplanned Cooldown Transient Occurred Due to Personnel Error.Trained & Briefed Personnel & Revised Procedures.With 990716 Ltr ML17241A4031999-07-0606 July 1999 LER 99-006-00:on 990605,sub-critical Reactor Trip Occurred Due to Inadvertent MSIV Opening.Caused by Personnel Error. Provided Operation Supervision Instruction to Operating Crews,Stand Down Meetings & Operator Aids.With 990706 Ltr ML17241A4041999-07-0606 July 1999 LER 99-005-00:on 990604,CEA Drop Resulted in Manual Reactor Trip.Caused by Procedural Inadequacies.Procedure Changes Are Planned to Correct Lack of Procedural Guidance for CEA Subgroup Power Switch Replacement.With 990706 Ltr ML17241A3941999-06-30030 June 1999 LER 99-004-01:on 990415,as Found Cycle 10 Psv Setpoints Were Outside TS Limits.Caused by Manufacturing Process Defect. All Three Psvs Were Replaced with pre-tested Valves During Cycle 11 Refueling Outage.With 990630 Ltr ML17241A3551999-06-0404 June 1999 LER 99-002-00:on 990505,both Trains of Safety Injection Actuation Were Blocked During Surveillance.Caused by Procedure Error.Procedure Revised.With 990604 Ltr ML17241A3321999-05-17017 May 1999 LER 99-004-00:on 990415,determined That as Found Cycle 10 Psv Setpoints Outside TS Limits.Root Cause Under Investigation.Psvs Replaced with pe-tested Valves During Cycle 11 ML17241A3271999-05-0606 May 1999 LER 99-003-00:on 990406,ECCS Suction Header Leak Resulted in Both ECCS Trains Being Inoperable & Entry Into TS 3.0.3. Caused by Chloride Induced OD Stress Corrosion Cracking of Piping.Made Code Repairs & Coated Piping.With 990506 Ltr ML17229B0791999-04-0707 April 1999 LER 99-001-00:on 990309,discovered Inadequate Design & IST SRs for Iodine Removal Sys (Irs).Caused by Original Design Inadequacies & Personnel Error.Naoh Tank Vent Valve V07233 Was Tagged Open.With 990407 Ltr ML17229B0801999-04-0707 April 1999 LER 99-002-00:on 990311,SG ECT Error Caused Operation with Condition Prohibited by Ts.Caused by Deficiencies in Data Analysis Guideline Instructions.Licensee Will Change Data Analysis Guidelines for Lead Analysts.With 990407 Ltr ML17229B0541999-03-10010 March 1999 LER 99-001-00:on 990211,inadequate TS SRs for SIT & SDC Isolation Valves Were Noted.Caused by Failure to Correctly Implement TS Srs.Submitted LAR to Align Required TS SR with Design Bases Requirements Being Verified.With 990310 Ltr ML17229A9901999-01-20020 January 1999 LER 98-009-00:on 981223,noted That Facility Operated Outside of Design Basis.Caused by non-conservative MSLB Analysis Inputs.Will Review SR Component Differences Between Units & Will re-baseline LTOP Analysis.With 990120 Ltr ML17229A9821999-01-0404 January 1999 LER 98-010-00:on 981207,RCS Boron Sample Frequency Required by Ts,Was Exceeded by Twelve Minutes.Caused by Personnel Error.Equipment Clearance Order Was Lifted to Draw Required Sample & Operations Procedure Was Changed.With 990104 Ltr ML17229A9611998-12-22022 December 1998 LER 97-002-01:on 981204,containment Sump Debris Screen Was Not IAW Design.Caused by Inadequate C/As for Sump Screen Anamolies.All Identified Sump Screen Deficiencies Were Dispositioned &/Or Repaired.With 981222 Ltr ML17229A9561998-12-15015 December 1998 LER 98-008-00:on 981118,missed TS SG U Tube Insp.Caused by Encoding Errors While Using Remote Positioning Fixtures.All SG Tube Surveyed.With 981215 Ltr ML17229A9301998-11-25025 November 1998 LER 98-005-01:on 980807,discovered That New MOV Methodology Caused Past PORV Block Valve Operability Problem.Caused by Inadequacies in Original Vendor MOV Methodology.Planned Valve Mods Will Be Implemented During Cycle 11 1998 Outage ML17229A9021998-11-0404 November 1998 LER 98-008-00:on 981008,inadequate Reactor Protection Sys Trip Bypass TS Was Noted.Caused by Poorly Worded Ts. Submitted LAR to Clarify Power Requirements for High Rate of Power Trips.With 981104 Ltr ML17229A8771998-10-14014 October 1998 LER 98-006-00:on 980918,inadvertent Afas Actuation Was Noted.Caused by Degradation of Multiple Afas Power Supplies. Replaced Afas Power Supplies & Revised Procedures.With 981014 Ltr ML17229A8761998-10-14014 October 1998 LER 98-007-00:on 980918,identified Discrepancies Between Fire Protection Design Requirements & Field Conditions. Caused by Inadequate Translation & Implementation of Fire Protection Requirements.Procedures Revised.With 981014 Ltr ML17229A8511998-09-0202 September 1998 LER 98-005-00:on 980807,discovered That PORV Margins Were Insufficient to Accommodate Addl Conservatism.Caused by Inadequacies in Original Vendor MOV Methodology.Will Implement Planned Valve Actuator mods.W/980902 Ltr ML17229A8201998-07-29029 July 1998 LER 98-007-00:on 980630,inadequate Procedure May Have Resulted in SBO Recovery Complications.Caused by Inadequate Procedures.Attached Caution Tags to Appropriate Control switches.W/980729 Ltr ML17229A7411998-05-28028 May 1998 LER 98-004-00:on 980430,discovered Waste Gas Decay Tank Operation W/O Available Oxygen Analyzers,Which Is Prohibited by Ts.Caused by Inadequate Licensee Review of License Amend. Oxygen Analyzer recalibrated.W/980528 Ltr ML17229A7381998-05-21021 May 1998 LER 98-006-00:on 980421,missed EDG Fuel Oil Sample Surveillance Was Noted.Caused by Personnel Error.Revised Fuel Oil Sampling Service Purchase Order & Revised Site procedure.W/980521 Ltr ML17229A7011998-04-27027 April 1998 LER 98-003-00:on 980326,discovered Containment Pressure Instrumentation Design Single Failure Vulnerability.Caused by Inadequate Design by Personnel Error.Removed RPS & ESFAS Containment Pressure Bypass Keys immediately.W/980427 Ltr ML17229A6761998-04-0202 April 1998 LER 98-005-00:on 980305,identified Two Conditions That Were Outside App R Design Bases.Caused by Design Oversight During Development of Original App R Safe SD Design.Established 30 Minute Roving Fire Watches & Provided training.W/980402 Ltr ML17229A6731998-03-26026 March 1998 LER 98-002-00:on 980224,radiation Monitor Surveillance Inadequacies Led to Operating of Facility Prohibited by Tss. Caused by Congnitive Personnel Error.Permanent Procedure Changes Were implemented.W/980326 Ltr ML17229A6551998-03-0505 March 1998 LER 98-001-00:on 980206,high/low Pressure Shutdown Cooling Interface Was Noted Outside App R Design Bases.Caused by Personnel Error.Addl Guidance Was Provided to Engineering Dept personnel.W/980305 Ltr ML17229A6281998-02-19019 February 1998 LER 98-004-00:on 980121,emergency Lighting Outside App R Design Bases Occurred.Caused by Congnitive Personnel Error During Translation of App R Section Iii.Procedures Onop 1 & 2 ONP-100.01 Were Issued for Use on 980206.W/980219 Ltr ML17229A6211998-02-0909 February 1998 LER 98-003-00:on 980110,manual Rt Due to DEH Leak at Turbine Test Block Was Noted.Caused by o-ring Extrusion.Shortened Bolts by About 0.125 & Reinstalled at Correct Torque values.W/980209 Ltr ML17229A6191998-02-0404 February 1998 LER 98-002-00:on 980105,CIS Bistable in Bypass Resulted in Condition Prohibited by Tss.Caused by Personnel Error. Radiation Monitor Was Restored to service.W/980204 Ltr ML17229A6161998-02-0303 February 1998 LER 98-001-00:on 980104,inadvertent RPS Actuation Occurred Due to Personnel Error.Caused by Procedural Inadequacies & Inadequate self-checking by Licensed Utility Personnel. Placards Have Been Placed in CRs.W/980203 Ltr ML17229A6051998-01-27027 January 1998 LER 97-010-01:on 971027,inadvertent Core Alteration Prohibited by TSs Were Noted Due to Stuck Cea.Caused by Personnel Error.Cea #24 Was Dislodged & Transferred to Spent Pool for insp.W/980127 Ltr ML17229A5501997-12-0505 December 1997 LER 97-008-00:on 971107,inadequate CR Ventilation Surveillance Resulted in Condition Prohibited by Ts.Caused by non-cognitive Personnel Error.Operating Procedure 2-1900050 Was revised.W/971205 Ltr ML17309A9091997-12-0202 December 1997 LER 97-011-00:on 971102,non-conservative RAS Set Point Resulted in Operation Prohibited by Ts.Caused by Inadequate Set Point & Instrument Loop Scaling Process.Revised ESFAS Functional Tp W/Proper Set point.W/971202 Ltr ML17229A5391997-11-26026 November 1997 LER 97-010-00:on 971027,inadvertant Core Alteration Prohibited by TS Occurred.Caused by CEA Failure to Detach from Ugs.Safety Evaluation Was Performed & Procedural Rev Made to Continue Upper Guide Structure move.W/971126 Ltr ML17229A5151997-11-0707 November 1997 LER 97-007-00:on 971008,inoperable Containment Cooling Fan Resulted in Operation of Facility Outside Design Basis. Caused by non-cognitive Personnel Error.Ccs Operation Was Revised & Issued on 971013.W/971107 Ltr ML17229A4991997-10-17017 October 1997 LER 97-009-00:on 970917,inoperable PORV Block Valve Resulted in Operation Prohibited by Tech Specs Occurred.Caused by Plant GL 89-10 Program Plan to Review Plant Manager Action Item Sys.Porv Block Valve V-1403 restored.W/971017 Ltr ML17309A9011997-08-27027 August 1997 LER 97-008-00:on 970728,mechanical Fire Penetrations Were Inoperable & Outside App R Design Bases.Caused by Seal Mfg Not Providing Formal Documentation for Installed Seals. Modified Inoperable Fire penetrations.W/970827 Ltr ML17229A4311997-07-29029 July 1997 LER 97-006-00:on 970630,discovered Inadequate Testing of Engineered Safety Features Subgroup Relays.Caused by Inadequacy in Implementing TS Requirements in Surveillance Procedures.Revised Surveillance procedures.W/970729 Ltr ML17229A4241997-07-25025 July 1997 LER 97-005-00:on 970625,discovered That Hot Shutdown Control Panel Shutdown Cooling Flow indicator,FI-3306 Inoperable. Caused by Weakness in Work Order & Procedure Used to Repair FI-3306.Section Meeting W/I&C Planners held.W/970725 Ltr ML17229A3971997-07-11011 July 1997 LER 97-004-00:on 970611,discovered Incorrect Original Cable Tray Fire Stop Assembly Installation Was Outside App R Design Basis.Caused by Personnel Error.Hourly Fire Watch Patrols Will Be posted.W/970711 Ltr ML17229A3871997-06-19019 June 1997 LER 97-003-00:on 970521,determined Required Post Maint Open Stroke Test for Valve V3245,2B2 SIT Discharge Check Valve, Had Not Been Performed.Caused by Personnel Error.Procedure revised.W/970619 Ltr ML17229A3841997-06-17017 June 1997 LER 97-002-00:on 970518,containment Sump Debris Screen Was Not IAW Design Due to Gaps in Screen Encl.Performed SER to Document Containment Sump Design requirements.W/970617 Ltr ML17229A3751997-06-0202 June 1997 LER 97-006-00:on 970501,operation Was Prohibited by TS Due to Inadequately Tested Degraded Voltage Sys.Revised Unit 1 ESFAS Surveillance Test procedure.W/970602 Ltr ML17229A3611997-05-29029 May 1997 LER 97-007-00:on 970502,reactor Coolant Pump Oil Collection Sys Was Outside App R Design Bases.Identified Leak Sites Were Repaired & Mods to RCP Oil Collection Sys to Capture Any Future Leakage from areas.W/970529 Ltr ML17229A3491997-05-21021 May 1997 LER 97-001-00:on 970423,containment Isolation Actuation Occurred.Caused by Increased Radiation Levels During Removal of Upper Guide Structure.Proper Actuation of Containment Isolation Components Was verified.W/970521 Ltr ML17229A3441997-05-13013 May 1997 LER 97-005-00:on 970419,reactor Was Shutdown Due to Reactor Coolant Pressure Boundary Leakage.Hot Cracking Was Caused by Weld Contamination.Repairs to RCPB Were Completed & 1A SDC Train Was Restored to Svc ML17229A3141997-04-30030 April 1997 LER 97-004-00:on 970402,refueling Machine Was Operating in Manner Prohibited by TS Due to Original Design of Refueling Machine Bypass Feature Conflicting W/Ts Requirements. Eliminated Overload Cut Off Limit bypass.W/970430 Ltr ML17229A2951997-03-31031 March 1997 LER 97-003-00:on 970304,automatic Rt Resulted from Loss of Electrical Power to 1A2 Rc Pump.Rcp Breaker Was Replaced & Pump Was Returned to svc.W/970331 Ltr ML17229A2721997-03-21021 March 1997 LER 97-002-00:on 970221,operation in Excess of Max Rated Thermal Power Occurred Due to Digital Data Processing Sys (Ddps) Calorimetric Error.Verified Acceptable Performance of Ddps Functions & Reviewed Software mods.W/970321 Ltr 1999-07-06
[Table view] Category:RO)
MONTHYEARML17241A4891999-10-0707 October 1999 LER 99-004-00:on 990912,noted That MSSV Surveillance Was Outside of TS Requirements.Caused by Setpoint Drift.Subject MSSVs Are Being Refurbished & Retested Prior to Unit Startup from SL1-16 Refueling Outage.With 991007 Ltr ML17241A4111999-07-16016 July 1999 LER 99-007-00:on 990610,unplanned Cooldown Transient Occurred Due to Personnel Error.Trained & Briefed Personnel & Revised Procedures.With 990716 Ltr ML17241A4031999-07-0606 July 1999 LER 99-006-00:on 990605,sub-critical Reactor Trip Occurred Due to Inadvertent MSIV Opening.Caused by Personnel Error. Provided Operation Supervision Instruction to Operating Crews,Stand Down Meetings & Operator Aids.With 990706 Ltr ML17241A4041999-07-0606 July 1999 LER 99-005-00:on 990604,CEA Drop Resulted in Manual Reactor Trip.Caused by Procedural Inadequacies.Procedure Changes Are Planned to Correct Lack of Procedural Guidance for CEA Subgroup Power Switch Replacement.With 990706 Ltr ML17241A3941999-06-30030 June 1999 LER 99-004-01:on 990415,as Found Cycle 10 Psv Setpoints Were Outside TS Limits.Caused by Manufacturing Process Defect. All Three Psvs Were Replaced with pre-tested Valves During Cycle 11 Refueling Outage.With 990630 Ltr ML17241A3551999-06-0404 June 1999 LER 99-002-00:on 990505,both Trains of Safety Injection Actuation Were Blocked During Surveillance.Caused by Procedure Error.Procedure Revised.With 990604 Ltr ML17241A3321999-05-17017 May 1999 LER 99-004-00:on 990415,determined That as Found Cycle 10 Psv Setpoints Outside TS Limits.Root Cause Under Investigation.Psvs Replaced with pe-tested Valves During Cycle 11 ML17241A3271999-05-0606 May 1999 LER 99-003-00:on 990406,ECCS Suction Header Leak Resulted in Both ECCS Trains Being Inoperable & Entry Into TS 3.0.3. Caused by Chloride Induced OD Stress Corrosion Cracking of Piping.Made Code Repairs & Coated Piping.With 990506 Ltr ML17229B0791999-04-0707 April 1999 LER 99-001-00:on 990309,discovered Inadequate Design & IST SRs for Iodine Removal Sys (Irs).Caused by Original Design Inadequacies & Personnel Error.Naoh Tank Vent Valve V07233 Was Tagged Open.With 990407 Ltr ML17229B0801999-04-0707 April 1999 LER 99-002-00:on 990311,SG ECT Error Caused Operation with Condition Prohibited by Ts.Caused by Deficiencies in Data Analysis Guideline Instructions.Licensee Will Change Data Analysis Guidelines for Lead Analysts.With 990407 Ltr ML17229B0541999-03-10010 March 1999 LER 99-001-00:on 990211,inadequate TS SRs for SIT & SDC Isolation Valves Were Noted.Caused by Failure to Correctly Implement TS Srs.Submitted LAR to Align Required TS SR with Design Bases Requirements Being Verified.With 990310 Ltr ML17229A9901999-01-20020 January 1999 LER 98-009-00:on 981223,noted That Facility Operated Outside of Design Basis.Caused by non-conservative MSLB Analysis Inputs.Will Review SR Component Differences Between Units & Will re-baseline LTOP Analysis.With 990120 Ltr ML17229A9821999-01-0404 January 1999 LER 98-010-00:on 981207,RCS Boron Sample Frequency Required by Ts,Was Exceeded by Twelve Minutes.Caused by Personnel Error.Equipment Clearance Order Was Lifted to Draw Required Sample & Operations Procedure Was Changed.With 990104 Ltr ML17229A9611998-12-22022 December 1998 LER 97-002-01:on 981204,containment Sump Debris Screen Was Not IAW Design.Caused by Inadequate C/As for Sump Screen Anamolies.All Identified Sump Screen Deficiencies Were Dispositioned &/Or Repaired.With 981222 Ltr ML17229A9561998-12-15015 December 1998 LER 98-008-00:on 981118,missed TS SG U Tube Insp.Caused by Encoding Errors While Using Remote Positioning Fixtures.All SG Tube Surveyed.With 981215 Ltr ML17229A9301998-11-25025 November 1998 LER 98-005-01:on 980807,discovered That New MOV Methodology Caused Past PORV Block Valve Operability Problem.Caused by Inadequacies in Original Vendor MOV Methodology.Planned Valve Mods Will Be Implemented During Cycle 11 1998 Outage ML17229A9021998-11-0404 November 1998 LER 98-008-00:on 981008,inadequate Reactor Protection Sys Trip Bypass TS Was Noted.Caused by Poorly Worded Ts. Submitted LAR to Clarify Power Requirements for High Rate of Power Trips.With 981104 Ltr ML17229A8771998-10-14014 October 1998 LER 98-006-00:on 980918,inadvertent Afas Actuation Was Noted.Caused by Degradation of Multiple Afas Power Supplies. Replaced Afas Power Supplies & Revised Procedures.With 981014 Ltr ML17229A8761998-10-14014 October 1998 LER 98-007-00:on 980918,identified Discrepancies Between Fire Protection Design Requirements & Field Conditions. Caused by Inadequate Translation & Implementation of Fire Protection Requirements.Procedures Revised.With 981014 Ltr ML17229A8511998-09-0202 September 1998 LER 98-005-00:on 980807,discovered That PORV Margins Were Insufficient to Accommodate Addl Conservatism.Caused by Inadequacies in Original Vendor MOV Methodology.Will Implement Planned Valve Actuator mods.W/980902 Ltr ML17229A8201998-07-29029 July 1998 LER 98-007-00:on 980630,inadequate Procedure May Have Resulted in SBO Recovery Complications.Caused by Inadequate Procedures.Attached Caution Tags to Appropriate Control switches.W/980729 Ltr ML17229A7411998-05-28028 May 1998 LER 98-004-00:on 980430,discovered Waste Gas Decay Tank Operation W/O Available Oxygen Analyzers,Which Is Prohibited by Ts.Caused by Inadequate Licensee Review of License Amend. Oxygen Analyzer recalibrated.W/980528 Ltr ML17229A7381998-05-21021 May 1998 LER 98-006-00:on 980421,missed EDG Fuel Oil Sample Surveillance Was Noted.Caused by Personnel Error.Revised Fuel Oil Sampling Service Purchase Order & Revised Site procedure.W/980521 Ltr ML17229A7011998-04-27027 April 1998 LER 98-003-00:on 980326,discovered Containment Pressure Instrumentation Design Single Failure Vulnerability.Caused by Inadequate Design by Personnel Error.Removed RPS & ESFAS Containment Pressure Bypass Keys immediately.W/980427 Ltr ML17229A6761998-04-0202 April 1998 LER 98-005-00:on 980305,identified Two Conditions That Were Outside App R Design Bases.Caused by Design Oversight During Development of Original App R Safe SD Design.Established 30 Minute Roving Fire Watches & Provided training.W/980402 Ltr ML17229A6731998-03-26026 March 1998 LER 98-002-00:on 980224,radiation Monitor Surveillance Inadequacies Led to Operating of Facility Prohibited by Tss. Caused by Congnitive Personnel Error.Permanent Procedure Changes Were implemented.W/980326 Ltr ML17229A6551998-03-0505 March 1998 LER 98-001-00:on 980206,high/low Pressure Shutdown Cooling Interface Was Noted Outside App R Design Bases.Caused by Personnel Error.Addl Guidance Was Provided to Engineering Dept personnel.W/980305 Ltr ML17229A6281998-02-19019 February 1998 LER 98-004-00:on 980121,emergency Lighting Outside App R Design Bases Occurred.Caused by Congnitive Personnel Error During Translation of App R Section Iii.Procedures Onop 1 & 2 ONP-100.01 Were Issued for Use on 980206.W/980219 Ltr ML17229A6211998-02-0909 February 1998 LER 98-003-00:on 980110,manual Rt Due to DEH Leak at Turbine Test Block Was Noted.Caused by o-ring Extrusion.Shortened Bolts by About 0.125 & Reinstalled at Correct Torque values.W/980209 Ltr ML17229A6191998-02-0404 February 1998 LER 98-002-00:on 980105,CIS Bistable in Bypass Resulted in Condition Prohibited by Tss.Caused by Personnel Error. Radiation Monitor Was Restored to service.W/980204 Ltr ML17229A6161998-02-0303 February 1998 LER 98-001-00:on 980104,inadvertent RPS Actuation Occurred Due to Personnel Error.Caused by Procedural Inadequacies & Inadequate self-checking by Licensed Utility Personnel. Placards Have Been Placed in CRs.W/980203 Ltr ML17229A6051998-01-27027 January 1998 LER 97-010-01:on 971027,inadvertent Core Alteration Prohibited by TSs Were Noted Due to Stuck Cea.Caused by Personnel Error.Cea #24 Was Dislodged & Transferred to Spent Pool for insp.W/980127 Ltr ML17229A5501997-12-0505 December 1997 LER 97-008-00:on 971107,inadequate CR Ventilation Surveillance Resulted in Condition Prohibited by Ts.Caused by non-cognitive Personnel Error.Operating Procedure 2-1900050 Was revised.W/971205 Ltr ML17309A9091997-12-0202 December 1997 LER 97-011-00:on 971102,non-conservative RAS Set Point Resulted in Operation Prohibited by Ts.Caused by Inadequate Set Point & Instrument Loop Scaling Process.Revised ESFAS Functional Tp W/Proper Set point.W/971202 Ltr ML17229A5391997-11-26026 November 1997 LER 97-010-00:on 971027,inadvertant Core Alteration Prohibited by TS Occurred.Caused by CEA Failure to Detach from Ugs.Safety Evaluation Was Performed & Procedural Rev Made to Continue Upper Guide Structure move.W/971126 Ltr ML17229A5151997-11-0707 November 1997 LER 97-007-00:on 971008,inoperable Containment Cooling Fan Resulted in Operation of Facility Outside Design Basis. Caused by non-cognitive Personnel Error.Ccs Operation Was Revised & Issued on 971013.W/971107 Ltr ML17229A4991997-10-17017 October 1997 LER 97-009-00:on 970917,inoperable PORV Block Valve Resulted in Operation Prohibited by Tech Specs Occurred.Caused by Plant GL 89-10 Program Plan to Review Plant Manager Action Item Sys.Porv Block Valve V-1403 restored.W/971017 Ltr ML17309A9011997-08-27027 August 1997 LER 97-008-00:on 970728,mechanical Fire Penetrations Were Inoperable & Outside App R Design Bases.Caused by Seal Mfg Not Providing Formal Documentation for Installed Seals. Modified Inoperable Fire penetrations.W/970827 Ltr ML17229A4311997-07-29029 July 1997 LER 97-006-00:on 970630,discovered Inadequate Testing of Engineered Safety Features Subgroup Relays.Caused by Inadequacy in Implementing TS Requirements in Surveillance Procedures.Revised Surveillance procedures.W/970729 Ltr ML17229A4241997-07-25025 July 1997 LER 97-005-00:on 970625,discovered That Hot Shutdown Control Panel Shutdown Cooling Flow indicator,FI-3306 Inoperable. Caused by Weakness in Work Order & Procedure Used to Repair FI-3306.Section Meeting W/I&C Planners held.W/970725 Ltr ML17229A3971997-07-11011 July 1997 LER 97-004-00:on 970611,discovered Incorrect Original Cable Tray Fire Stop Assembly Installation Was Outside App R Design Basis.Caused by Personnel Error.Hourly Fire Watch Patrols Will Be posted.W/970711 Ltr ML17229A3871997-06-19019 June 1997 LER 97-003-00:on 970521,determined Required Post Maint Open Stroke Test for Valve V3245,2B2 SIT Discharge Check Valve, Had Not Been Performed.Caused by Personnel Error.Procedure revised.W/970619 Ltr ML17229A3841997-06-17017 June 1997 LER 97-002-00:on 970518,containment Sump Debris Screen Was Not IAW Design Due to Gaps in Screen Encl.Performed SER to Document Containment Sump Design requirements.W/970617 Ltr ML17229A3751997-06-0202 June 1997 LER 97-006-00:on 970501,operation Was Prohibited by TS Due to Inadequately Tested Degraded Voltage Sys.Revised Unit 1 ESFAS Surveillance Test procedure.W/970602 Ltr ML17229A3611997-05-29029 May 1997 LER 97-007-00:on 970502,reactor Coolant Pump Oil Collection Sys Was Outside App R Design Bases.Identified Leak Sites Were Repaired & Mods to RCP Oil Collection Sys to Capture Any Future Leakage from areas.W/970529 Ltr ML17229A3491997-05-21021 May 1997 LER 97-001-00:on 970423,containment Isolation Actuation Occurred.Caused by Increased Radiation Levels During Removal of Upper Guide Structure.Proper Actuation of Containment Isolation Components Was verified.W/970521 Ltr ML17229A3441997-05-13013 May 1997 LER 97-005-00:on 970419,reactor Was Shutdown Due to Reactor Coolant Pressure Boundary Leakage.Hot Cracking Was Caused by Weld Contamination.Repairs to RCPB Were Completed & 1A SDC Train Was Restored to Svc ML17229A3141997-04-30030 April 1997 LER 97-004-00:on 970402,refueling Machine Was Operating in Manner Prohibited by TS Due to Original Design of Refueling Machine Bypass Feature Conflicting W/Ts Requirements. Eliminated Overload Cut Off Limit bypass.W/970430 Ltr ML17229A2951997-03-31031 March 1997 LER 97-003-00:on 970304,automatic Rt Resulted from Loss of Electrical Power to 1A2 Rc Pump.Rcp Breaker Was Replaced & Pump Was Returned to svc.W/970331 Ltr ML17229A2721997-03-21021 March 1997 LER 97-002-00:on 970221,operation in Excess of Max Rated Thermal Power Occurred Due to Digital Data Processing Sys (Ddps) Calorimetric Error.Verified Acceptable Performance of Ddps Functions & Reviewed Software mods.W/970321 Ltr 1999-07-06
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML17241A4891999-10-0707 October 1999 LER 99-004-00:on 990912,noted That MSSV Surveillance Was Outside of TS Requirements.Caused by Setpoint Drift.Subject MSSVs Are Being Refurbished & Retested Prior to Unit Startup from SL1-16 Refueling Outage.With 991007 Ltr ML17241A4951999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for St Lucie,Units 1 & 2.With 991014 Ltr ML17241A4741999-08-31031 August 1999 Rev 1 to PCM 99016, St Lucie Unit 1,Cycle 16 Colr. ML17241A4591999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for St Lucie,Units 1 & 2.With 990913 Ltr ML17241A4301999-07-31031 July 1999 Monthly Operating Repts for Jul 1999 for St Lucie Units 1 & 2.With 990805 Ltr ML17241A4111999-07-16016 July 1999 LER 99-007-00:on 990610,unplanned Cooldown Transient Occurred Due to Personnel Error.Trained & Briefed Personnel & Revised Procedures.With 990716 Ltr ML17241A4031999-07-0606 July 1999 LER 99-006-00:on 990605,sub-critical Reactor Trip Occurred Due to Inadvertent MSIV Opening.Caused by Personnel Error. Provided Operation Supervision Instruction to Operating Crews,Stand Down Meetings & Operator Aids.With 990706 Ltr ML17241A4041999-07-0606 July 1999 LER 99-005-00:on 990604,CEA Drop Resulted in Manual Reactor Trip.Caused by Procedural Inadequacies.Procedure Changes Are Planned to Correct Lack of Procedural Guidance for CEA Subgroup Power Switch Replacement.With 990706 Ltr ML17241A4091999-06-30030 June 1999 Monthly Operating Repts for June 1999 for St Lucie,Units 1 & 2.With 990712 Ltr ML17241A3941999-06-30030 June 1999 LER 99-004-01:on 990415,as Found Cycle 10 Psv Setpoints Were Outside TS Limits.Caused by Manufacturing Process Defect. All Three Psvs Were Replaced with pre-tested Valves During Cycle 11 Refueling Outage.With 990630 Ltr ML17355A3681999-06-30030 June 1999 Revised Update to Topical QA Rept, Dtd June 1999 ML17241A3551999-06-0404 June 1999 LER 99-002-00:on 990505,both Trains of Safety Injection Actuation Were Blocked During Surveillance.Caused by Procedure Error.Procedure Revised.With 990604 Ltr ML17241A3631999-05-31031 May 1999 Monthly Operating Repts for May 1999 for St Lucie Units 1 & 2.With 990610 Ltr ML17241A3321999-05-17017 May 1999 LER 99-004-00:on 990415,determined That as Found Cycle 10 Psv Setpoints Outside TS Limits.Root Cause Under Investigation.Psvs Replaced with pe-tested Valves During Cycle 11 ML17241A3271999-05-0606 May 1999 LER 99-003-00:on 990406,ECCS Suction Header Leak Resulted in Both ECCS Trains Being Inoperable & Entry Into TS 3.0.3. Caused by Chloride Induced OD Stress Corrosion Cracking of Piping.Made Code Repairs & Coated Piping.With 990506 Ltr ML17241A3331999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for St Lucie,Units 1 & 2.With 990517 Ltr ML17229B0801999-04-0707 April 1999 LER 99-002-00:on 990311,SG ECT Error Caused Operation with Condition Prohibited by Ts.Caused by Deficiencies in Data Analysis Guideline Instructions.Licensee Will Change Data Analysis Guidelines for Lead Analysts.With 990407 Ltr ML17229B0841999-04-0707 April 1999 Rev 2 to PSL-ENG-SEMS-98-102, Engineering Evaluation of ECCS Suction Lines. ML17229B0791999-04-0707 April 1999 LER 99-001-00:on 990309,discovered Inadequate Design & IST SRs for Iodine Removal Sys (Irs).Caused by Original Design Inadequacies & Personnel Error.Naoh Tank Vent Valve V07233 Was Tagged Open.With 990407 Ltr ML17229B0961999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for St Lucie,Units 1 & 2.With 990408 Ltr ML17229B0541999-03-10010 March 1999 LER 99-001-00:on 990211,inadequate TS SRs for SIT & SDC Isolation Valves Were Noted.Caused by Failure to Correctly Implement TS Srs.Submitted LAR to Align Required TS SR with Design Bases Requirements Being Verified.With 990310 Ltr ML17229B0461999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for St Lucie,Units 1 & 2.With 990310 Ltr ML17229B0051999-01-31031 January 1999 Monthly Operating Repts for Jan 1999 for St Lucie,Units 1 & 2.With 990211 Ltr ML17229A9901999-01-20020 January 1999 LER 98-009-00:on 981223,noted That Facility Operated Outside of Design Basis.Caused by non-conservative MSLB Analysis Inputs.Will Review SR Component Differences Between Units & Will re-baseline LTOP Analysis.With 990120 Ltr ML17229A9961999-01-14014 January 1999 SG Tube Inservice Insp Special Rept. ML17229A9821999-01-0404 January 1999 LER 98-010-00:on 981207,RCS Boron Sample Frequency Required by Ts,Was Exceeded by Twelve Minutes.Caused by Personnel Error.Equipment Clearance Order Was Lifted to Draw Required Sample & Operations Procedure Was Changed.With 990104 Ltr ML17229A9831998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for St Lucie,Units 1 & 2.With 990111 Ltr ML17229A9611998-12-22022 December 1998 LER 97-002-01:on 981204,containment Sump Debris Screen Was Not IAW Design.Caused by Inadequate C/As for Sump Screen Anamolies.All Identified Sump Screen Deficiencies Were Dispositioned &/Or Repaired.With 981222 Ltr ML17229A9561998-12-15015 December 1998 LER 98-008-00:on 981118,missed TS SG U Tube Insp.Caused by Encoding Errors While Using Remote Positioning Fixtures.All SG Tube Surveyed.With 981215 Ltr ML17241A3581998-12-0909 December 1998 Changes,Tests & Experiments Made as Allowed by 10CFR50.59 for Period of 970526-981209. ML17229A9421998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for St Lucie,Units 1 & 2.With 981215 Ltr ML17229A9301998-11-25025 November 1998 LER 98-005-01:on 980807,discovered That New MOV Methodology Caused Past PORV Block Valve Operability Problem.Caused by Inadequacies in Original Vendor MOV Methodology.Planned Valve Mods Will Be Implemented During Cycle 11 1998 Outage ML17229A9021998-11-0404 November 1998 LER 98-008-00:on 981008,inadequate Reactor Protection Sys Trip Bypass TS Was Noted.Caused by Poorly Worded Ts. Submitted LAR to Clarify Power Requirements for High Rate of Power Trips.With 981104 Ltr ML17241A4931998-11-0101 November 1998 Statement of Account for Period of 981101-990930 for Suntrust Bank,As Trustee for Florida Municipal Power Agency Nuclear Decommissioning Trust (St Lucie Project). ML17229A9051998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for St Lucie,Units 1 & 2.With 981110 Ltr ML17229A8871998-10-19019 October 1998 Part 21 Rept Re Potential Defect in Swagelok Stainless Steel Front Ferrule,Part Number SS-503-1 Which Was Machined with Improper Length.C/A Includes Insp Equipment That Will 100% Identify Short Length ML17229A8781998-10-19019 October 1998 Part 21 Rept Re Potential Defect in Swagelok Stainless Steel Front Ferrule,Part Number SS-503-1,which Was Machined with Improper Length.Insp Equipment That Will 100% Identify Short Length ML17229A8771998-10-14014 October 1998 LER 98-006-00:on 980918,inadvertent Afas Actuation Was Noted.Caused by Degradation of Multiple Afas Power Supplies. Replaced Afas Power Supplies & Revised Procedures.With 981014 Ltr ML17229A8761998-10-14014 October 1998 LER 98-007-00:on 980918,identified Discrepancies Between Fire Protection Design Requirements & Field Conditions. Caused by Inadequate Translation & Implementation of Fire Protection Requirements.Procedures Revised.With 981014 Ltr ML17229A8721998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for St Lucie Units 1 & 2.With 981009 Ltr ML17229A8511998-09-0202 September 1998 LER 98-005-00:on 980807,discovered That PORV Margins Were Insufficient to Accommodate Addl Conservatism.Caused by Inadequacies in Original Vendor MOV Methodology.Will Implement Planned Valve Actuator mods.W/980902 Ltr ML17229A8611998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for St Lucie,Units 1 & 2.With 980911 Ltr ML18066A2771998-08-13013 August 1998 Part 21 Rept Re Deficiency in CE Current Screening Methodology for Determining Limiting Fuel Assembly for Detailed PWR thermal-hydraulic Sa.Evaluations Were Performed for Affected Plants to Determine Effect of Deficiency ML17229A8481998-08-0707 August 1998 Rev 1 to PSL-ENG-SEFJ-98-013, St Lucie Unit 2,Cycle 10 Colr. ML17229A9461998-08-0707 August 1998 Rev 0 to PCM 98016, St Lucie Unit 2,Cycle 11 Colr. ML17229A8301998-07-31031 July 1998 Monthly Operating Repts for July 1998 for St Lucie,Units 1 & 2.W/980814 Ltr ML17229A8201998-07-29029 July 1998 LER 98-007-00:on 980630,inadequate Procedure May Have Resulted in SBO Recovery Complications.Caused by Inadequate Procedures.Attached Caution Tags to Appropriate Control switches.W/980729 Ltr ML17229A7981998-06-30030 June 1998 Monthly Operating Repts for June 1998 for St Lucie,Units 1 & 2.W/980713 Ltr ML17229A7701998-05-31031 May 1998 Monthly Operating Repts for May 1998 for St Lucie,Units 1 & 2.W/980612 Ltr ML17229A7411998-05-28028 May 1998 LER 98-004-00:on 980430,discovered Waste Gas Decay Tank Operation W/O Available Oxygen Analyzers,Which Is Prohibited by Ts.Caused by Inadequate Licensee Review of License Amend. Oxygen Analyzer recalibrated.W/980528 Ltr 1999-09-30
[Table view] |
Text
REGULA,Y INFORMATION DISTR I BUT I YSTEM ( R IDS )
ACCESSION NBR: 8802020148 DOC. DATE: 88/01/29 NOTARIZED: NO DOCKET ¹ FACIL: 50-389 St. Lucie Plant> Unit 2> Florida Poeer 5 Light Co. 05000389 AUTH. NAME AUTHOR AFFILlATION JOHNSON'. B. Fl or i da Poeer 5 Light Co.
WOODY. C. O. Florida Power 5 Light Co.
REC IP. NAME RECIPIENT AFFILIATION
SUBJECT:
LER 87-007-01: on 871125. reactor tripped on loss of load due to turbine trip. Caused bg personnel error. Permanent magnet generator 5 exciter bearing replaced Zc exciter bearing thermocouple removed. W/880129 ltr.
DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ENCL SIZE:
TITLE: 50. 73 Licensee Event Report (LER) i Incident Rpti etc.
NOTES:
REC IP IENT COPIES REC IP IENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 TOURIGNYi E 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/NAS 1 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 ARM/DCTS/DAB 1 DEDRO 1 1 NRR/DEST/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 NRR/DEST/ICSB 1 1 NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 1 NRR/DEST/SGB 1 NRR/DLPG/HFB 1 NRR/DLPG/GAB 1 1 NRR/DOEA/E*B 1 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 A)R /SIB 1 1 NRR/PMAS/ILRB 1 1 REG FILE 02 1 1 RES TELFORDi J 1 1 IB 1 1 RES/DRPS DIR 1 1 RGN2 FILE 01 1 1 EXTERNAL: EG5G GROHi M 5 5 FORD BLDG HOY> A 1 H ST LOBBY WARD 1 1 LPDR" 1 1 NRC PDR 1 1 NSIC HARRIS> J 1 1 NSIC MAYST G 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 46 ENCL 45
NRC Form 3SSA U.S, NUCLEAR REGULATORY COMMISSION 19413 l LICENSEE ENT REPORT (LER) TEXT CONTINUA ION APPROVED OMB NO. 3150&104 EXPIRES: 9/31/BB FACILITY NAME III OOCKET NUMBER Ill LER NUMBER IBI PAGE 0)
St. Lucie, Unit 2 YEAR @~a.
NvM Err xo,: REvrsroN SFOVENT/AL iM NVM Ell o s o o o 3 89 '87 007 0 1 0 2 OF 0 4 TEXT /ifmoro s/rsco is rsr/rr/rsd, rrso sddio'orrs/ H/IC Fonrr 3////A'/ (IT)
DESCRIPTION OF ENTENTE On 25 November, 1987, St. Lucie Unit Two was operating at 50 percent power steady state in Mode 1. The unit was returned to service on 23 November following a refueling outage and was holding at 50 percent power while repairs were in progress on the 2A Steam Generator Feed Pump (SGFP) (EIIS:SJ) due to a small water leak that developed on the vent line at the pump casing. The reactor was being maintained in a steady state condition with all automatic controllers placed in automatic with the exception of the Control Rod Drive System (EIZS:JD) which was in OFF.
At 2331 hours0.027 days <br />0.648 hours <br />0.00385 weeks <br />8.869455e-4 months <br />, the Reactor Protective System (EIZS:JC) initiated a reactor trip on loss of load due to a turbine trip. The turbine tripped on a main generator (EIIS:TB) lockout. The control room was alerted with information that smoke was seen coming out of the Main Generator Exciter (EZIS:TL). The Assistant Nuclear Plant Supervisor (ANPS) instructed the Turbine Operator (TO) to check for rubs on the rotating components of the turbine-generator. The TO reported evidence of turbine-generator rubs to the control room and the ANPS instructed the Reactor Control Room Operators (RCOs) to open the vacuum breakers on the main condenser (EIZS:SG) to aid in slowing down the turbine.
A fire team was assembled and stationed with fire fighting equipment at the vicinity of the main generator exciter. There were no reports of an actual fire.
The trip was an uncomplicated trip and all systems functioned normally. The Steam Bypass Control System (SBCS) (EIIS:JI) operated to reduce primary average temperature (T-avg) to the zero percent power setpoint of 532 degrees F. Auxiliary feedwater (EIZS:BA) was initiated manually to control the steam generator (S/G) level for Reactor Coolant System (RCS) (EIZSEAB) heat removal. The standard post trip actions were completed and the unit was immediately stabilized in Hot Standby, Mode 3.
NRC FORM 316A 19831
NRC Form 3ddA V.S. NUCLEAR REGULATORY COMMISSION (983)
LICENSE ENT REPORT (LER) TEXT CONTINU ON APPROVEO OMS NO. 3150MI(H EXP!RES: 8/3(188 FACILITY NAME (I) DOCKET NUMBER (3) LER NVMSER (8) PACE (3)
SEQUENTIAL REVISION YEAR @g NUM tR NUM ER St. Lucie, Unit 2 o s o o o 0 0 7 0 1 0 3 OF 0 4 TERT (Ilmoro <<>>oo b ror)rrr'rod, Ir>> odds'onel NRC Farm 3ddl3 I ()T)
CAUSE OF TBB EVENTS The immediate cause of the main generator lockout was loss of the generator field. The loss of field was caused by destruction of the exciter Permanent Magnet Generator (PMG) that occurred when the exciter bearing failed allowing the PMG armature to rub on the PMG stator.
Further investigation into the failure of the exciter bearing indicated that a ground was caused by a completed electrical circuit between the exciter bearing and the exciter base. This completed electrical circuit bypassed the insulation between the bearing pedestal and the exciter base. The ground was caused by an improper installation of an instrument cable (EIIS:IT). The instrument cable provides the terminal connection from the thermocouple of the N9 exciter bearing housing to its terminal box, which provides remote temperature indication in the control room. The as-found condition of the instrument cable indicated that the braided wire cable shield was not properly positioned in the clamp; therefore, a ground developed at the exciter bearing. Examination of the exciter bearing revealed pitting marks on the bearing surface, characteristic of current flowing across the bearing journal to the bearing pad, which resulted in the bearing failure.
The improper arrangement of the instrument cable cannot be conclusively identified as a wiring error during the installation of the new main generator exciter.
The PMG and the instrument cable were meggered to detect for possible grounds and the results were acceptable. It has been postulated that one of two circumstances may have occurred: 1) the instrument cable was installed correctly with the braided wire shield in the clamp when it was meggered; then at some later date, the instrument cable was accidently stepped on causing the cable shield to become separated from the clamp; or 2) the instrument cable, being clamped incorrectly to the pedestal, had not yet been connected to the terminal box when the megger test was performed.
After placing the main generator back in service, the ground should have been detected during the performance of the weekly generator exciter ground check.
The preventative maintenance Plant Work Order (PWO) requires voltages to be read across the N9 bearing shaft to ground and across the 59 bearing pedestal to ground. The data is to be evaluated to ensure no grounds have developed in the main generator exciter. Early recognition of the ground would have prompted immediate action to remove the main generator from service for the necessary repairs.
The root cause of the event was a cognitive personnel error by a utility main-tenance supervisor in misinterpretation of the main generator exciter ground voltage readings. The appropriate procedure was properly followed. However, lack of understanding of the significance of the generator exciter ground check and inadequate acceptance criteria in the PWO were contributing factors in the personnel error. There were no unusual characteristics of the work location that directly contributed to the personnel error.
NRC fORM 3ddA (983)
URC Form 366A U.S. NVCLEAR RECULATORY COMMISSION (983)
LICENSEE NT REPORT (LER) TEXT CONTINUA ON APPROVED OMB NO. 3150WIOi EXPIRES: 8/31/88 FACILITY NAME (11 DOCKET NUMBER (2) LER NUMBER (6) PACE (3)
YEAR SEOUENTIAL REVISION NUMBER NUM Ell St. Lucie, Unit 2 p 5 p p p 3 8 9 8 7 0 0 7 0 1 0 4 OF 0 4 TEXT /I/mort t/Mcoit ror)rr/rtd. Ihto tdChr/ont/HRC Forrrr 36(L('ti (17)
ANALYSIS OF THE EVENT:
The event is reportable under 10 CFR 50.73 (a)(2)(iv), "any event or condition that resulted in manual or automatic actuation of any Engineered Safety Feature, including the Reactor Protection System."
This event was observed to be a routine reactor trip on loss of load. The resulting transient was well enveloped by the St. Lucie Unit II2 Final Updated Safety Analysis Report section 15.2.1.2 "Limiting Reactor Coolant System Pressure Event-Isolation of Turbine (100% power)." All Plant Safety Functions were met and there were no additional complications. Consequently, the health and safety of the public were not affected by this event.
CORRECTIVE ACTIONS.
- 1. The Permanent Magnet Generator was replaced.
- 2. The Exciter Bearing was replaced.
- 3. An evaluation was made and'the Exciter Bearing thermocouple was determined to be unnecessary type.
and it was removed to prevent future incidents of this
- 4. The preventative maintenance plant work order was revised to adequately define the acceptance criteria and the proper actions when the acceptance criteria are not met.
- 5. Training was given to all Electrical Maintenance personnel to elaborate on the importance of properly evaluating the data during performance of the weekly generator exciter ground check. h
- 6. The plant training group will evaluate this item to determine appropriate training requirements and methods.
ADDITIONAL INFORMATION:
FAILED COMPONENT INFORMATION:
Westinghouse Exciter Bearing (89 bearing)
Part I)613F432 GOl PREVIOUS SIMILAR EVENTS:
See LER 5389-84-011 for a previous reactor trip due to exciter bearing failure.
NRC FORM 366*
(983)
P. O. 14000, JUNO BEACH, FL 33408.0420 SKNLI5 2 9 1988 L-88-41 10 CFR 50,73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555
, Gentlemen:
Re: St. Lucie Unit 2 Docket No. 50-389 Reportable Event: 87-07 Revision 1 Date of Event: November 25, 1987 Reactor Trip on Loss of Load Caused by Main Generator Exciter Bearin Failure Due to Personnel Error The attached Licensee Event Report (LER) is being submitted pursuant to the requirements of 10 CFR 50.73 to provide an update on the subject event.
Very truly yours, C. 0. ody Executive Vice President COW/GRM/gp Attachment cc: Dr. J. Nelson Grace, Regional Administrator, Region ZI, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant GRM/022.LER an FPL Group company