ML16251A413
| ML16251A413 | |
| Person / Time | |
|---|---|
| Issue date: | 06/12/1992 |
| From: | Ward D Advisory Committee on Reactor Safeguards |
| To: | Selin I, The Chairman NRC COMMISSION (OCM) |
| References | |
| ACRS-R-1476, NUDOCS 9206240391 | |
| Download: ML16251A413 (18) | |
Text
June 12, 1992 Docket Nos. 50-269, 50-270 and 50-287 LICENSEE:
Duke Power Company FACILITY:
Oconee Nuclear Station, Units 1, 2, and 3
SUBJECT:
SUMMARY
OF JUNE 4, 1992, MEETING ON ELECTRICAL DISTRIBUTION SYSTEM ISSUES AT THE OCONEE NUCLEAR STATION On June 4, 1992, the NRC staff met with representatives of Duke Power Company (DPC) to review recent operating events associated with the Oconee electrical system, the status of electrical system Design Basis Documentation (DBD) reviews, and the results of a licensee conducted Electrical Distribution System Functional Inspection (EDSFI).
The DPC presentation began with Mr. D. M. Jamil, Oconee Electrical Engineering, describing a recent event involving defective anti-pumping relays (X-relay) installed in several Keowee hydro station breakers and an event involving low closing coil voltage on the 'E',
'S,' and 'Sk' breakers.
Mr. Jamil then provided an update of the status of electrical DBDs, and the status and schedule for significant electrical system modifications. The DPC presentation concluded with Mr. R. Dobson, Electrical Engineering Manager, providing a brief overview of the licensee conducted EDSFI audit and a summary of general conclusions.
After a brief caucus, it was the consensus of the NRR, AEOD, and Region II representatives that, based on the current programs and schedule presented by DPC during the meeting, no acceleration of the schedule for the NRC EDSFI (now scheduled for January 1993) appears warranted.
Meeting participants are listed in Enclosure 1. Handouts distributed by DPC during the presentation are provided in Enclosure 2.
/s/
L. A. Wiens, Project Manager Project Directorate 11-3 Division of Reactor Projects I/II
Enclosures:
DISTRIBUTION:
As stated See next page cc w/enclosures:
See next page OFFICIAL RECORD COPY C:OCOMTGSM OFC
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- L.WIENS:rs :. ATTHEWS DATE : 6/; / 2 : 6/1-k192
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2055 June 12, 1992 Docket Nos. 50-269, 50-270 and 50-287 LICENSEE:
Duke Power Company FACILITY:
Oconee Nuclear Station, Units 1, 2, and 3
SUBJECT:
SUMMARY
OF JUNE 4, 1992, MEETING ON ELECTRICAL DISTRIBUTION SYSTEM ISSUES AT THE OCONEE NUCLEAR STATION On June 4, 1992, the NRC staff met with representatives of Duke Power Company (DPC) to review recent operating events associated with the Oconee electrical system, the status of electrical system Design Basis Documentation (DBD) reviews, and the results of a licensee conducted Electrical Distribution System Functional Inspection (EDSFI).
The DPC presentation began with Mr. D. M. Jamil, Oconee Electrical Engineering, describing a recent event involving defective anti-pumping relays (X-relay) installed in several Keowee hydro station breakers and an event involving low closing coil voltage on the 'E',
'S,' and 'Sk' breakers.
Mr. Jamil then provided an update of the status of electrical DBDs, and the status and schedule for significant electrical system modifications. The DPC presentation concluded with Mr. R. Dobson, Electrical Engineering Manager, providing a brief overview of the licensee conducted EDSFI audit and a summary of general conclusions.
After a brief caucus, it was the consensus of the NRR, AEOD, and Region II representatives that, based on the current programs and schedule presented by DPC during the meeting, no acceleration of the schedule for the NRC EDSFI (now scheduled for January 1993) appears warranted.
Meeting participants are listed in Enclosure 1. Handouts distributed by DPC during the presentation are provided in Enclosure 2.
L. A. Wiens, Project Manager Project Directorate 11-3 Division of Reactor Projects I/II
Enclosures:
As stated cc w/enclosures:
See next page
Mr. J. W. Hampton Duke Power Company Oconee Nuclear Station cc:
Mr. A. V. Carr, Esquire Mr. M. E. Patrick Duke Power Company Compiance 422 South Church Street Duke Power Company Charlotte, North Carolina 28242-0001 Oconee Nuclear Site P. 0. Box 1439 J. Michael McGarry, III, Esquire Seneca, South Carolina 29679 Winston and Strawn 1400 L Street, NW.
Mr. Alan R. Herdt, Chief Washington, DC 20005 Project Branch #3 U. S. Nuclear Regulatory Commission Mr. Robert B. Borsum 101 Marietta Street, NW. Suite 2900 Babcock & Wilcox Atlanta, Georgia 30323 Nuclear Power Division Suite 525 Ms. Karen E. Long 1700 Rockville Pike Assistant Attorney General Rockville, Maryland 20852 North Carolina Department of Justice Manager, LIS P. 0. Box 629 NUS Corporation Raleigh, North Carolina 27602 2650 McCormick Drive, 3rd Floor Clearwater, Florida 34619-1035 Mr. R. L. Gill, Jr.
Licensing Senior Resident Inspector Duke Power Company U. S. Nuclear Regulatory Commission P. 0. Box 1007 Route 2, Box 610 Charlotte, North Carolina 28201-1007 Seneca, South Carolina 29678 Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta Street, NW. Suite 2900 Atlanta, Georgia 30323 Mr. Heyward G. Shealy, Chief Bureau of Radiological Health South Carolina Department of Health and Environmental Control 2600 Bull Street Columbia, South Carolina 29201 Office of Intergovernmental Relations 116 West Jones Street Raleigh, North Carolina 27603 County Supervisor of Oconee County Walhalla, South Carolina 29621
ENCLOSURE 1 LIST OF ATTENDEES DUKE POWER COMPANY STATION BLACKOUT MEETING JUNE 4, 1992 NAME ORGANIZATION L. Wiens NRR/PDII-3 D. Matthews NRR/PDII-3 J. M. Davis DUKE/OCONEE B. L. (Jack) Davis DUKE/OCONEE ENGINEERING M. Patrick DUKE/OCONEE COMPLIANCE R. Gill DUKE/CORPORATE LICENSING D. Deatherage DUKE/OCONEE OPERATIONS R. L. Dobson DUKE/ELECTRICAL ENGINEER D. M. Jamil DUKE/ELECTRICAL ENGINEER L. J. Azzarello DUKE/MECHANICAL/NUCLEAR ENGINEER B. B. Desai NRC/RESIDENT INSPECTOR/OCONEE M. S. Sills DUKE/OCONEE ENGINEERING R. P. Colaianni DUKE/CORPORATE LICENSING T. Koshy NRC/DOEA/EAB M. B. Shymlock NRC/RII/EB-PSS C. Julian NRC/RII/EB-DRS S. Mazumdar NRC/AEOD E. J. Brown NRC/AEOB/ROAB H. Ornstein NRC/AEOD/ROAB A. Toalston NRC/DST/SELB P. Gill NRC/DST/SELB F. Rosa NRC/DST/SELB G. C. Lainas NRC/DRPE J. Hampton DUKE/OCONEE SITE VICE PRESIDENT
ENCLOSURE 2 ELECTRICAL SYSTEM STATUS UPDATE
- Keowee X-Relay Problem
- Switchgear Closing Coil Voltage Problem
- DBD Status
- Significant Activities
- EDS SITA Audit Results
KEOWEE X COIL PROBLEM
- 1.
"X" coil is the Westinghouse DB25 and DB50 Antipump relays.
- 2.
Westinghouse DB Breakers are used in both Keowee units in the following applications:
Field Breaker Field Supply Breaker Field Flash Breaker ACB5 ACB6 ACB7 ACB8 Load Center 1X and 2X Breakers
- 3.
Concern is mechanical binding of relay after a Keowee unit shutdown which could prevent automatic restart of associated Keowee unit.
- 4.
First problem investigation report was issued in June 1991 when Keowee Unit #1 failed a performance test. All Commercial Grade "X" relays were replaced with vendor certified 1E relays. Westinghouse was notified of the problem.
- 5.
"X" relay failure reported again on January 29, 1992.
- 6.
Failure was reported in LER #269/92-02 and Westinghouse was notified of the problem.
- 7.
Compensatory procedures were put in place until problem is resolved.
- 8.
Modification is in progress to replace "X" relay with different design.
Project completion of modification is early July 1992.
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0 SWITCHGEAR COIL VOLTAGE PROBLEM 125VDC DBD -
Open item.
a Voltages at Switchgear close coil were calculated to be below minimum published voltage due to long cable runs.
a Calculations assume worst case allowable conditions.
a Switchgear successfully tested by manufacturer to voltage levels compatible with calculated values.
a The specific breakers were all successfully tested to voltage levels below calculated values.
Enhancement modification was completed by April 15, 1992 to correct problem.
OCONEE NUCLEAR STATION Power System 230/525KV
- Keowes, Lee Sw itch yards Hydroelectic CT Generators Genersters 2C0K Unes ts sUm NORMA STATU RCP.cu ou SA36ENI MA3GFIEDEde wm
%Alp Ni~~~~~T NCMTSWE I~Li*
Breaker Length of #12 Minimum Close Voltage Calculated Tested Ell 3600 ft.
67.8 V 55.0 V E2, 4110 65.2 V 49.1 V El2 3600 67.8 V 57.0 V E22 4110 65.2 V 56.5 V E13 4200 64.8 V 56.0 V E2z 4710 62.4 V 53.0 V SI, 2520 74.1 V 63.5 V S2, 2746 72.7 V 52.5 V S12 2520 74.1 V 47.0 V S22 2746 72.7 V 55.0 V S3 4602 62.9 V 58.5 V S23 5175 60.4 V 56.0 V SKI 3532 68.2 V 4288 64.4 V 56.6 V 5172 60.4 V SK2 3636 67.6 V 4316 64.2 V 53.7 V 5316 59.8 V
OCONEE ELECTRICAL DBD'S COMPLETE 230 KV Switchyard Power 4 KV Auxiliary Power System 125 VDC Vital I&C Power Reactor Protective System Engineered Safety Features Actuation System Keowee Emergency Power ATWS 600/208 VAC Safety Power System 230KV Switchyard 125VDC Power Lee Emergency Power Inadequate Core Cooling Monitoring Security 1992 1993 Integrated Control System Keowee 125VDC power 120VAC Vital I&C Power Nuclear Instrumentation 600/208/120 VAC SSF Power 125VDC SSF Power 4160VAC SSF Power Control Rod Drive Fire Detection ASP/Loss of Control Room 1994 1995 Area Radiation Monitoring Evacuation Alarm Plant Computer Meteorological Instr Process Radiation Monitoring Reactor Coolant Pump Monitor
SIGNIFICANT RECENTLY COMPLETED ITEMS AND MODIFICATIONS a
230KV Switchyard Power Circuit Completed 1989 Breaker Replacement a
New 230KV Switchyard degraded Completed 1990 grid protection system a
Power System Coordination Calc Completed 1991 Safety related relay setting Cale Completed 1991 a
16MVA non-safety related Auxiliary Completed 1992 Power System Expansion a
Completed the following DBD's:
4KV (including Switchyard logic)
Completed 1989 230KV Switchyard Power System Completed 1990 Keowee Emergency Power System Completed 1990 125VDC Vital I & C System Completed 1990 600V/208V/120V Power System Completed 1991 230KV Switchyard 125VDC System Completed 1991 Lee Emergency Power System Completed 1991 m
Other Corrective Items List:
RBS Motor Relay Setting PCB Capacitor Changeout EPSL Control Power Change Cable Separation EPSL Single Failure Lee Emergency Power Upgrade Switchyard Isolate Enhancement Keowee spare Auxiliary Transformer Keowee Overload Fault Pressure Relay Changes Switchyard Relay Setting Changes Breaker Coordination Keowee ACB Control Circuit Interlock Switchgear Coil Voltage Upgrade Several Calcs documenting system adequacy
SIGNIFICANT ON-GOING ITEMS AND MODIFICATIONS a
Central Switchyard degraded grid Sched. Completion 6/92 protection Mod a
230KV Switchyard Battery Sched. Completion 10/92 Replacement a
Enhanced Technical Specification Planned Submittal 1992 3.7 m
525KV/230KV Switchyard Auto Bank Sched. Completion 1992 Transformer Replacement a
DBD Open Item Calculations Sched. Through 1993 m
Keowee Generator Breaker Sched. Completion 1994 Replacement (ACB 1, 2, 3, & 4) a Safety related and non safety Sched. Completion 1994 related battery charger and inverter replacement -
all three units, switchyard, and Keowee n
Emergency Power Switching Logic Sched. Completion 1994 enhancement Mod a
Keowee Intake Structure Modification Sched. Completion 1994
SELF INITIATED TECHNICAL AUDIT (SITA)
EDSFI m
EDSFI - SITA performed between March 23 and May 8, 1992 by Southern Technical Services, Inc.
Basic Guidance for audit was NRC Temporary Instruction (TI) 2515/107 "Electrical Distribution System Functional Inspection a
Team Consisted of:
Team Leader Two Electrical Design Engineers One Mechanical Design Engineer Two Electrical Field Engineers
GENERAL CONCLUSIONS m
Design and implementation of the EDS at Oconee generally acceptable.
E Additional documentation is necessary to demonstrate EDS adequacy under certain Design Basis scenarios.
Engineering and Plant Support organizations adequately structured.
N Areas requiring further evaluation:
Short Circuit Overduty Routine Keowee Unit Operation Seismic Design Basis Tornado Loading HVAC Analysis Classification of Keowee Components Inservice testing of Keowee Mechanical support systems Relay Calibration Program Configuration Control of Sliding Links Labeling Program Low Voltage Switchgear Maintenance Equipment Trending Program.
STRENGTHS
- 1.
Design of the relay protection schemes for EDS and offsite source.
- 2.
Quality and usefulness of EDS Design Basis Documents.
- 3.
Quality of EDS Calculations.
- 4.
Familiarity of EDS Engineering Staff with details and bases of system design and calculations.
SCHEDULE FOR RESPONSE m
SITA Report was received on May 18, 1992.
a No formal review of findings by Duke Power Company yet.
m Responses to report findings and follow-up items are due to Duke Power Company Quality Verification Department in late July.
MEETING
SUMMARY
DATED June 12, 1992 DISTRIBUTION FDocket File)
NRC/LOCAL PDRs PDH1-3 READING T.MURYLEY/F.MIRAGLIA J.PARTLOW S.VARGA G.LAINAS D.MATTHEWS L.WIENS L.BERRY OGC E.JORDAN ACRS (10)
L.REYES, RH J.WECHSELBERGER,.EDO E.ROSSI B.B.DESAI, RESIDENT INSPECTOR/OCONEE T.KOSHY M.B.SHYMLOCK C.JULIAN S.MAZUMDAR E.J.BROWN H.ORNSTEIN A.TOALSTON P.GILL F.ROSA