05000335/LER-1995-001, :on 950216,during Portion of Surveillance Test for 1A3 4160 Volt Bus Degraded Voltage relay,27-5 Relay Failed to Operate Due to Procedural Deficiency.Ops Verified All Equipment Responded as Expected
| ML17228B063 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 03/17/1995 |
| From: | Lyons E, Sager D FLORIDA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| L-95-088, L-95-88, LER-95-001, LER-95-1, NUDOCS 9503200180 | |
| Download: ML17228B063 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(x) |
| 3351995001R00 - NRC Website | |
text
4 R.IC)R.IWY
(ACCELERATED RIDS PROCESSING)
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION 'NBR:9503200180 DOC.DATE: 95/03/17 NOTARIZED: NO FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power
& Light Co.
AUTH.NAME AUTHOR AFFILIATION LYONS,E.E.
Florida Power
& Light Co.
SAGER,D.A.
Florida Power
& Light Co.
RECIP.NAME RECIPIENT AFFILIATION DOCKET 05000335
SUBJECT:
LER 95-001-00:on 950216,during portion of surveillance test for 1A3 4160 volt bus degraded voltage relay,27-5 relay failed to operate due to procedural deficiency.Ops verified all equipment responded as expected.W/950317 ltr.
DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:
TITLE: 50.73/50.9 Licensee Event Report (LER), Zncident Rpt, etc.
NOTES:
RECIPIENT ID CODE/NAME PD2-2 PD INTERNAL: ACRS AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DOPS/OECB NRR/DRCH/HICB NRR/DRSS/PRPB NRR/DSSA/SRXB RGN2 FILE 01 EXTERNAL: L ST LOBBY WARD NOAC MURPHY,G.A NRC PDR COPIES LTTR ENCL 1
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~F-ZLE CENTERS 02 NRR/DE/EELB NRR/DISP/PIPB NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DSSA/SPLB RES/DSIR/EIB LZTCO BRYCE,J H
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1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACTTHE DOCUMENTCONTROL DESK, ROOhI P! -37 (EXT. 504-2083 ) TO ELlhIINATE YOUR NAMEFROM DISTRIBUTIONLISTS FOR DOCUMENTS YOU DON'T NEED!
FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED:
LTTR 28 ENCL 28
Florida Power & Light Company, P.O. Box 128, Fort Pierce, FL 34954-0128 March 17, 1995 L-95-088 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, D. C.
20555 Re:
St. Lucie Unit 1 Docket No. 50-335 Reportable Event:
95-001 Date of Event:
February 16, 1995 1A3 4160 Volt Bus Load Shed Durin e lacement of Failed 2X-5 Rela Due to Procedural Deficienc The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.
Very truly yours, D. A.
er Vice P e ident St.
Lu 'lant DAS/EJB Attachment cc: Stewart D. Ebneter, Regional Administrator, USNRC Region II Senior Resident Inspector, USNRC, St. Lucie Plant 9503200i80 9503i7 PDR ADOCK 05000335 PDR an FPL Group company
NRC FORH 366 (5-92)
U.S.
NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 5/31/95 Z1CmSZZ EVENT RZPOZT (ZZR)
(See reverse for required nunber of digits/characters for each block)
ESTIMATED BURDEN PER
RESPONSE
TO COMPLY WITH THIS INFORMATION COLLECTION REOUEST:
50.0 NRS.
FORWARD COMMENTS REGARDING BURDEN ESTIHATE TO THE INFORMATION AND RECORDS MANAGEHENT BRANCH (MNBB 7714), U.S.
NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104),
OFFICE OF MANAGEMENT AND BUDGET
'WASHINGTON DC 20503.
FACILITY NAHE (1)
St. Lucie Unit 1 DOCKET NUHBER (2) 05000335 PAGE (3) 1 OF 4 TITLE (4) 1A3 4160 Volt Bus Load Shed During Replacement of Failed 2X-5 Relay due to MONTH DAY YEAR EVENT DATE (5)
YEAR LER NUMBER (6)
SEOUENTIAL NUMBER REVISION NUHBER REPORT DATE (7)
DOCK>T NUMBER FACILITY NAME YEAR N/A MONTH DAY OTHER FACILITIES INVOLVED (8) 02 16 95 95
--001--
03 17 FACILITY NAME N/A DOCKET NUMBER OPERATING MODE (9)
POWER LEVEL ('lo) 100 THIS REPORT IS SUBHITTED PURSUANT 20.402(b) 20 '05(a)('l)(i) 20.405(a)(1)(ii) 20.405(a)(1)(iii) 20.405(a)(1)(iv) 20 '05(a)(1)(v) 20.405(c) 50.36(c)(1) 50.36(c)(2) 50.73(a)(2)(i) 50.73(a)(2)(ii) 50.73(a)(2)(iii)
X 50.73(a)(2)(iv) 50.73(a)(2)(v) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(x) 73.71 (b) 73.71(c)
OTHER (Speci fy in Abstract beloM and in TextTO THE REQUIREMENTS OF 10 CFR 5:
(Check one or more) (11)
LICENSEE CONTACT FOR THIS LER (12)
NAME Edward E. Lyons, Shift Technical Advisor TELEPHONE NUMBER (Include Area Code)
(407) 465-3550 x3151 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE
SYSTEM X
EB COMPONENT MANUFACTURER A348 REPORTABLE TO NPRDS
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS SUPPLEMENTAL REPORT EXPECTED (14)
YES (If yes, complete EXPECTED SUBMISSION DATE).
X No EXPECTED SUSHI S SION DATE (15)
MONTH DAY YEAR ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typeMritten lines)
(16)
On 2/9/95 at 1840, Operations (Ops) was performing the monthly Channel Functional Test on the Undervoltage/Degraded voltage relaying scheme.
During the portion of the surveillance test for the 1A3 4160 volt bus degraded voltage relaying, the 27-5 relay failed to operate.
On 2/16/95 at 1100, Electrical Maintenance (EM) began the process of chanciing out the 2X-5 relay.
At 1145, as a jumper was being reiiioved, it inadvertently came in contact with terminal 2 on the 2X-6 relay.
This made up the deciraded voltage actuation circuit and the 1A3 4160 volt bus was shed.
The 1A Emergency Diesel Generator started and loaded on to the 1A3 4160 volt bus.
All ecLuipment responded as expected.
The root cause of the event was due to procedural deficiency.
Corrective actions for the event are:
1)
Ops verified all equipment respceded as expected,
- 2) Ops restored power to the 1A3 4160 volt bus per ONOP 1-0910054, 3)
EM completed the change out procechue for the 2X-5 relay, 4)
Ops performed the surveillance test of the 1A3 4160 volt bus degraded voltage relaying with satisfactory results, 5)
EM changed out all remaining 2X relays on both trains on Unit 1 and 6) A checklist will be developed to enhance St. Lucie Plant Policy 105 implementation.
NRC FORM 66 (5-92)(5-92)
U.S.
NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION APPROVED BY OMB NO. 3150-0104 EXPIRES 5/31/95 ESTIMATED BURDEN PER
RESPONSE
TO COMPLY WITH THIS INFORMATION COLLECTIOH REQUEST:
50.0 HRS.
FORWARD COMHENTS REGARDIHG BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MAHAGEMENT BRANCH (MNBB 7714), U.S.
NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AHD TO THE PAPERWORK REDUCTION PROJECT (3180-0104),
OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503.
FACILITY NAME (1)
St. Lucie Unit 1 DOCKET NUMBER (2) 05000335 YEAR 95 LER NUMBER (6)
SEQUENTIAL NUHBER
--001--
REVISION NUMBER PAGE (3) 2OF4 TEXT (If more space is required, use additional copies of HRC Form 366A)
(17)
On February 9, 1995 at 1840, Operations was performing the Technical Specification required monthly Channel Funct).onal Test on the Undervoltage/Degraded voltage relaying scheme.
During the portion of the surveillance test for tIie 1A3 4160 volt bus, degraded voltage relay, (EIIS:JE) 27-5'relay failed to operate.
Technical Specification 3.3.2.1 states that with the number of operable Channels one less than the Total Number of
- Channels, operation may proceed until performance of the next required channel functional test provided the inoperable channel is placed in the tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
The 27-5 relay was placed in the tripped condition at 1910 by installing an electrical jumper across terminals 1 and 2 on the 2X-5 relay.
The 2X-5 relay is a timing relay actuated by the 27-5 relay.
The 2X-5 relay, in conjunction with the 2X-6 relay that is actuated by the 27-6 relay, make up the normal 2 out of 2 logic for degraded voltage protection.
With the jumper on the 2X-5 relay the logic for degraded voltage protection was 1 out of l.
Subsequent non-intrusive trouble shooting performed by the electrical maintenance department revealed that the 2X-5 relay had failed and required replacement.
A procedure was developed by Electrical Maintenance to change the relay out on line.
Electrical Maintenance presented the procedure to plant management stating that the relay could be changed out on line but not without some risk of load shed of the 1A3 4160 volt bus or possibly the undervoltage/degraded voltage relaying scheme being rendered inoperable due to the confined wiring arrangement.
At this point plant management invoked St. Lucie Plant Policy PSL-105 which provides guidance for a Technical Subcamittee to be formed to review proposed actions that have risk to plant operations.
The subcommittee included ~rs from Technical Staff, Operations, Site Engineering, Electrical Maintenance and Plant Licensing.
The subcalmlittee was tasked with reve.ewing &e proposed procedure for impact on the plant, technical accuracy and to evaluate the consequences of various fax.lure modes associated with the procedure.
After a ccmprehensive review of the proposed procedure the subcaT(nittee provided the following malformation to the Facility Review Group (FRG):
The relay could be changed out on line with little additional risk of a plant trip.
This recaanenychtion was based on a detailed circuit analysis and a historical review of a similar event in the past in which the 1A3 4160 volt bus was load shed due to an undervoltage relay problem and the plant remained on-line. The subcaTrnittee also recaanendel the following ccmpensatory measures to be implemented prior to the relay change out:
- 1) Electrical namtenance supervision shall conduct a tailboard meeting prior to caTlnencement of work.
- 2) Independent verification shall be performed.
- 3) Electrical Maintenance shall utilize "mini-grabber" type jumpers.
- 4) The operating crew shall review QNOP 1-0910054, "LOSS OF A SAFETY RELATED A.C. BUS," and consider potential impact on unit and appropriate contingency actions.
- 6) Electrical maintenance shall insulate exposed leads.
- 7) Ensure spare fuses for the undervoltage relaying circuit were available at the work location in the event that the D.C. control power was zzadvertently shorted.
The FRG concluded that the relay change out could proceed without imposing undue safety risk.
NRC-FORM 66A (5-92)
HRC FORM 366A (5-92)
AS.
NUCLEAR REGULATORY COMMISSION LX~EE EVENT REPORT (LER)
TEXT CONTORTION PPROVED BY OMB NO. 3150-0104 EXPIRES 5/31/95 ESTIMATED BURDEN - PER
RESPONSE
TO COMPLY NTH THIS INFORMATION COLLECTION REQUEST:
50.0 HRS.
FORMARD COMMENTS REGARDIHG BURDEN ESTIMATE TO THE INFORMATION AHD RECORDS MANAGEMENT BRANCH (MNBB 7714),
U.ST NUCLEAR REGULATORY COMMISSION, MASHIHGTON, DC 20555-0001 AND TO THE PAPERllORK REDUCTION PROJECT (3180-0104),
OFFICE OF MANAGEMENT AND BUDGET llASHIHGTOH DC 20503.
FACILITY NAME (1)
St. Lucie Unit 1 DOCKET NUMBER (2) 05000335 YEAR 95 LER NUMBER (6)
SEQUENTIAL NUMBER
--001--
REVISIOH NUMBER PAGE (3) 3OF4 TEXT (If more space is required, use additional copies of NRC Form 366A)
(17)On 2/16/95 at 1100, following extensive tailboards with Operations and Maintenance personnel, Electrical Maintenance began the process of changing out the 2X-5 relay.
Steps 1 through 34 of a 38 step procedure were completed without ancient.
Step 35 called for the jumper that was keeping the 27-5 relay in trip to be removed to allow the surveillance test to be completed.
This jumper was, fran terminal 1 on the 2X-1 relay to terminal 1 on the 2X-6 relay.
At 1145, after the 2X-5 relay was replaced, as the jumper was being removed frcm terminal 1 on the 2X-6 relay it ~dvertently came in contact with terminal 2 on the 2X-6 relay.
This made up the degraded voltage actuation circuit and the 1A3 4160 volt bus was sheB.
The 1A Emergency Diesel Generator (EIIS:EK) started and loaded on to the 1A3 4160 volt bus.
All equipment responded as expected.
The event had minimal impact on the plant due to the cc(0pensatory measures reccmnended by the subcar(Iu.ttee being in lace.
Offsite power was restored to the 1A3 4160 volt bus at 1207 and the channel unctional test for degraded voltage was c(mpleted at 1247.
The root cause of the event was due to procedural deficiency.
The Technical subccoTIIittee was asked to critically reevaluate the event.
The team came up with the following considerations for future Technical subccmLittee reviews:
Provide more detailed review of the sequence in which the ends of jumpers are landed and remcmd to minimize the impact of inadvertent contact with adjacent terminals, evaluate conseqLIences of shorting of adjacent wires and other wires which could be easily shorted, review specific methods of insulating close proximity adjacent terminals and possibly utilize jumpers with series toggles switches to open circuit the jumper prior to disconnection.
This event is reportable under 10 CFR 50.73.a.2.iv as "any event or condition that resulted in manual or automatic actuation of any engineered safety feature, including the Reactor Protective System (RPS) (EIIS:JC)."
Only one train of safety related canponents was temporarily de-energized during the event.
The 1A EDG started and loaded onto the safety related bus as designed.
The redundant safety related train was available for service and the plant reIIazned in a stable condition throughout the entire event.
Offsite power was always available to both electrical trains during this event.
Thus, the health and safety of the public were not affected at any time during the event.
FPL supplied failed DSC relays to National Technical Systems (NTS) so that they could be analyzeel and a cause for the failures could be determined.
NTS concluded free visual ctions and unit functional testing that the failures were caused by natural aging of the units since installation, in the environment in which the relays were being installed.
This event is not applicable to both units as Unit 2 does not use Agastat DSC relays in the degraded grid circuit.
HRC-FORM 366A ( -92)
HRC FORM 366A (5-92)
U.ST NUCLEAR REGULATORY COMMISSION Z,zmmSZZ ZVZNT RZPORT (re)
TEXT CONTINUATION APPROVED BY OMB HO. 3150-0104 EXPIRES 5/31/95 ESTIMATED BURDEN PER
RESPONSE
TO COMPLY WITH THIS IHFORHATION COLLECTION REQUEST:
50 '
HRS.
FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE IHFORHATION AND RECORDS MANAGEHENT BRANCH (MHBB 7714), U.S.
NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104),
OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503.
FACILITY NAME (1)
St. Lucie Unit 1 DOCKET NUMBER (2)
YEAR 05000335 c)5 LER NUMBER (6)
SEQUENTIAL NUMBER
--001--
REV IS ION HUMBER PAGE (3) 4 OF 4 TEXT (If more space is required, use additional copies of HRC Form 366A)
(17)
- 1) Operations verified all equipment responded as expected.
- 2) Operations restored power to the 1A3 4160 volt bus per ONOP 1-0910054.
- 3) Electrical Maintenance canpleted the change out procedure for the 2X-5 relay.
- 4) Operations performed the surveillance test of the 1A3 4160 volt bus degraded voltage relaying with satisfactory results.
- 5) Electrical Maintenance changed out all remaining 2X relays on both trains on Unit 1.
- 6) A checklist will be developed to enhance St. Lucie Plant Policy 105 implementation.
Caqmnent Failures:
Amerace Corp Agastat Time Delay Relay Model DSCXX0125DP LER 335-94-002 "Inadvertent Load Shed of the 1A3 4160 Volt Bus due to Procedural Inadequacy"