ML15260A271
| ML15260A271 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 02/14/1992 |
| From: | Gibson A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Hampton J DUKE POWER CO. |
| References | |
| NUDOCS 9203030237 | |
| Download: ML15260A271 (32) | |
Text
February 14, 1992 Docket Nos. 50-269, 50-270, 50-287 License Nos. DPR-38, DPR-47, DPR-55 Duke Power Company ATTN:
Mr. J. W. Hampton Vice President Oconee Site P. 0. Box 1439 Seneca, SC 29679 Gentlemen:
SUBJECT:
MANAGEMENT MEETING
SUMMARY
OCONEE UNITS 1, 2 AND 3 This letter refers to the management meeting at our request on February 5,
- 1992, in the Nuclear Regulatory Commission (NRC)
Region II Office.
Items discussed included:
items.identified during the Design Basis Documentation Program Evaluations and Self Initiated Technical Audits of the Oconee Electrical Systems and the corrective actions initiated on the identified problems. A list of attendees, a meeting summary and copy of your handouts are enclosed.
Based on information presented during this meeting, the NRC will conduct the Electrical Distribution System Functional Inspection at Oconee site beginning in early Spring of 1993.
In accordance with Section 2.790 of the NRC's "Rules and Practice" Part 2, Title 10, Code of Federal Regulations, a copy of this letter and its enclosures will be placed in the NRC Public Document Room.
Should you have any questions concerning this matter, please contact us.
Sincerely, Original signed by Albert F. Gibson Albert F. Gibson, Director Division of Reactor Safety
Enclosures:
- 1. List of Attendees
- 2. Meeting Summary
- 3. Meeting Handouts cc w/encls:
(See page 2) 9203030237 920214 PDR ADOCK 05000269 PDR
Duke Power Company 2
February 14, 1992 cc w/encls:
A. V. Carr, Esq Duke Power Company 422 South Church Street Charlotte, NC 28242-0001 County Supervisor of Oconee County Walhalla, SC 29621 Robert B. Borsum Babcock and Wilcox Company Nuclear Power Generation Division Suite 525, 1700 Rockville Pike Rockville, MD 20852 J. Michael McGarry, III, Esq.
Winston and Strawn 1400 L Street, NW Washington, D. C. 20005 Office of Intergovernmental Relations 116 West Jones Street Raleigh, NC 27603 Heyward G. Shealy, Chief Bureau of Radiological Health South Carolina Department of Health and Environmental Control 2600 Bull Street Columbia, SC 29201 Manager, LIS NUS Corporation 2650 McCormick -Drive Clearwater, FL 34619-1035 R. L. Gill Nuclear Production Department Duke Power Company P. 0. Box 1007 Charlotte, NC 28201-1007 Karen E. Long Assistant Attorney General N. C. Department of Justice P. 0. Box 629 Raleigh, NC 27602 M. E. Patrick Compliance Duke Power Company P. 0. Box 1439
- Seneca, SC
.29679 bcc w/encls:
(See page 3)
Duke Power Company 3
February 14, 1992 bcc w/encl:
L. Wiens, NRR J. Knight, NRR S. Mazumdar, NRR J. Johnson, RII W. Miller, RH G. A. Belisle, RII A. R. Herdt, RII P. Harmon, RII Document Control Desk NRC Resident Inspector U.S. Nuclear Regulatory Commission Route 2, Box 610 Seneca, SC 29678 RII:DRS RHI:DRS1 RII:DR R I DS MShymlock:er lis'le CJulian AG n
02/1/92 02/L/921 02/;j/92 02/
92
ENCLOSURE 1 LIST OF ATTENDEES Duke Power Company J. W..Hampton, Vice President, Oconee Nuclear Station (ONS)
J. M. Davis, Safety Assurance Manager, ONS B. L. Peele, Site Engineering Manager, ONS M. E. Patrick, Regulatory Compliance Manager, ONS P. L. Dobson, Electrical Engineering Manager, ONS D.. Jamil, Electrical Engineering Supervisor, ONS.
Nuclear Regulatory Commission A. F. Gibson, Director, Division of Reactor Safety (DRS), Region II (RH1)
L. A. Reyes, Director, Division of Reactor Projects (DRP), RII E. W. Merschoff, Deputy Director, DRS, PT J. R. Wchrson, Deputy Director, DRP, PII C. A. Julian, Chief, Engineering Branch, DRS, RII T. A. Peebles, Chief, Operations Branch, DRS, PIT A. P. Herdt, Chief, Reactor Projects Branch 3, DRP, RI N. B. Shymlock, Chief, Plant Systems Section, DRS, RII L. A. Wiens, Oconee Project Manager, Project Directorate 11-3, Office of Nuclear Reactor Regulation (NRR)
- j. E. Knight, Section Chief. Electrical System Branch (SELB), NRR B. A. Breslau, Team Leader, Electrical Distribution System Functional Inspection (EDSFI), DRS, RI E. H. Girard,.Team Leader, EDSFI, DRS, PII S. Mazumdar, Reactor Operations Analysis Branch, Office for Analysis and Evaluation of Operational Data (AEOD/ROAB), NPP E. J. Brown, AEOD/ROAS, NRP P. E. Harmon, Senior Resident inspector, Oconee, DRP, Section 3A, RH W. H. Miller, Jr. Project Engineer, DRP, Section 3A, PhI F. H. Burrows, Technical Reviewer, SELB, NRR R. L. Mcore, Reactor Engineer, DRS, RII G. T. MacDonaTd, Reactor Engin~er, DRS, RI M. N. Miller, Reactor Engineer, DRS, PII J. L. Shackleford, intern, DRS, RII
ENCLOSURE 2 Management Meeting Summary February 5, 1992 Representatives from Duke Power Company's (DPC)
Oconee Nuclear Station (ONS) met with the NRC in the Region II Office in Atlanta, Georgia, on February 5, 1992.
Following opening remarks by.Mr. A. F. Gibson, Director. Divisionof Reactor Safety, and introduction of individuals present, Mr. J. W. Hampton, Vice President, ONS discussed the agenda for DPC's presentation, Enclosure 3.
The DPC presentation began.with
- r. R. L. Dobson, Electrical Ennineerino
Mr. D. V. Jani, E.ectrical Engineering Supervisor,
- ONS, discussed the chronology of events and cr program that had identified problems with the ONS electrical distribution system.
Then the corrective actions related to iden.tified problems were summarized.
Mr. R. L. Dobson, then summarized the findings from the DPC Self Initited Technical Audit of ONS's Emergency Power Distribution System including the Emergency Power Switching Logic System. The ONS Design Basis Documentation (DBD)
Program was discussed which included a list of completed DBD's and a projected schedule for those to be ccnducted through 19C95.
Mr. J. W. Hampton then summarized theDPC's presentation, and Mr. A. F. Gibson made some closing comments and the meeting was adjourned.
Enclos
- 3 OCONEE NUCLEAR STATION ELECTRICAL POWER SYSTEM NRC INFORMATION MEETING FEBRUARY 5, 1992
AGENDA INTRODUCTION SYSTEM DESCRIPTION EVENTS/PROGRAMS CORRECTIVE ACTION
SUMMARY
INTRODUCTION OCONEE SYSTEM VERY FLEXIBLE AND RELIABLE SEVERAL LERS SUBMITTED 1987 - 1991 INFORMATION SHARING MEETING IN WASHINGTON JUNE 1989 MOST IDENTIFIED BY DUKE IN PLANNED EFFORT FEW OF THESE DISCOVERIES WERE SAFETY SIGNIFICANT COMPREHENSIVE ACTIONS BEING TAKEN
STANDARD NUCLEAR PLANT A
B DIGDI A
B0 B
B U
U S
S
OCONEE NUCLEAR STATION Power System 230/525KV Keowee Lee Switchyards Hydroelectric CT Generators Generators 4 Double Circuit
.i 230KV Lines 3 525KV Lines eoed uIUIIWUUm u
u uIWIium IIIIWIU IiiuIuiiiiiiu u IuI I Iu un IU Line CENTRAL LAR SWITCH4YARD 1T CTI Keowee NORMAL STARTUP Underground SOURCE SOURCE Feeder CT4 CTS To CT2 STANDBY SKI SK2 SL1 SL2 IT BUSESj 44EE S*
AI2I RC1P RCP RCP RCP IAl 11 A2 1B2 TO UNIT 2 TO UNIT 3 MAIN FEEDER MAIN FEEDER BUSES BUSES
( t l AUNIT 1 N1 N2 MAIN FEEDER El E2 81 S2 BUSES MF91 MF82 1 reI lie I
1TE
KEOWEE (N.
oVILLE)
(CETRAL CEAAL)
DACUS OCONEE CALHOUN (FUT 1) w w
I230IKV R525 KV L
a ei (a
(wy_
y 13 19 31SENT1 I-I FUT2)
FUT3 JCASSE A~
a, Aur 0i Fi 60 MA 60 MVA
~
~24CV 525 LJa
- Il wanam ae a..a ieJilJy so8.
A S
N Ad (Fu 7) NORCROSS (Fur 2) uFUT3 j JOCASSE' (GA. POWER) ll LEI T
CT2 CT33 60OR 430 Rttt 60tVA (CFUTAL 4)FUS we19452 Io VA CTS 19KV Ioi EE NUCLEAR STATION 20 LAIA525-230KV.
AIOOKV/4.IG
+/-s2ILoff ASWITCHING STATION 1 ALL DISC. SW5 55 r
aED *.
K lit a.---~-
0j I
16004T5 Z30 RL.v Vi.
~
a l
- _._lOEE-64 4
8 PCB'S 230kV SWITCHYARD ix ACB1 Ax ACB3 AC4 MCCC XA UNIT UNIT MCC SXA TO CT4 MCC. 1XS MCC 2XS
SYSTEM DESCRIPTION TYPICAL PLANT TWO DIESELS, TWO SAFETY TRAINS SINGLE FAILURE ONE INOPERABLE TRAIN RIGID 72 HOUR LCO PERMITTED NO SINGLE FAILURE ONE TRAIN UNAVAILABLE OCONEE DESIGN MAIN FEEDER BUS - DOUBLE BUS/DOUBLE BREAKER - ONE NEEDED NORMAL SOURCE IS AUXILIARY TRANSFORMER STARTUP SOURCE FROM 230 KV SWITCHYARD PROVIDES ABILITY TO FEED RCP's WITH LOOP EMERGENCY SOURCE IS KEOWEE - TWO UNITS - ONE NEEDED; HIGHLY RELIABLE TWO PATHS FOR KEOWEE - OVERHEAD VIA SWITCHYARD OR UNDERGROUND TWO STANDBY BUSES (ONE NEEDED) FED FROM KEOWEE OR LEE DIVERSE POWER SOURCE AVAILABILITY 230 KV SWITCHYARD (4 DOUBLE CIRCUIT LINES DIVERSE PATHS) 525 KV SWITCHYARD (VIA AUTOTRANSFORMER 3 CIRCUITS)
KEOWEE OVERHEAD KEOWEE UNDERGROUND LEE COMBUSTION TURBINES (ONE NEEDED)
CENTRAL SWITCHYARD (100 KV)
OTHER UNITS 72 HOUR LCO PERMITTED
EMERGENCY POWER SWITCHING LOGIC (EPSL)
SYSTEM INTELLIGENCE TWO REDUNDANT CHANNELS POWER SEEKING WILL NOT SWITCH IF POWER AVAILABLE AFFECTS TRANSFERS OF MAIN FEEDER BUS SOURCES INPUT = VOLTAGE SENSING OUTPUT = BREAKER TRIP/CLOSE PERMISSIVES SINGLE FAILURES LEAVE SYSTEM INTACT CAN TOLERATE SOME MULTIPLE FAILURES 24 HOUR LCO LOCA UNIT KEOWEE STARTS - AVAILABLE APPROX. 12 - 16 SEC.
TRANSFERS TO STANDBY IF STARTUP SOURCE NOT AVAILABLE AT T= II SEC. -- LOAD SHEDS LOOP UNIT KEOWEE STARTS - AVAILABLE IN 12 - 16 SEC.
TRANSFERS TO STANDBY IF STARTUP SOURCE NOT AVAILABLE AT T= 31 SEC. -- LOAD SHEDS RETRANSFER TO STARTUP CONCLUSION:
COMPLEX SYSTEM FLEXIBLE SYSTEM HIGHLY RELIABLE SYSTEM
7/86 1/87 7/87 1/88 7/88 1/89 7/89 SSFI HPI MOTOR RELAYING LEE TRANSIENT STAN.DBY BUS CAPABILITY FROM CENTRAL TOPFORTESTING TOPFOR DBD SITA STANDBY BKR SINGLE. FAILURE
= POSTULATED EVENT
= PROGRAM DIRECT INFLUENCE INDIRECT INFLUENCE OCONEE EMERGENCY POWER SYSTEM PROGRAMS/POSTULATED EVENTS
7/86 1/87 7/87 1/88 7/88 1/89 7/89 9/89 TECH TECHI SPEC ROIND CLARIFY REWR EPSL FUNCTIONAL CTr4REMOVAL DSG RIIG*
UISFROM SERVICE SIJY ISIIN oL RX TRIP EHC GROUND LOSS OF TWO MAIN FEEDER BUS FEEDE BUS..............................................
UNT3LOSS.
OFPOWER EPSL FERRORESONANCE MODEL
= POSTULATED EVENT CABLE FIRE-CABLE DATA SEPARATION BASE
=
PROGRAM EPSL SINGLE FAILURE DIRECT INFLUENCE
.... INDIRECT INFLUENCE 525 KV TRANSIENT OCONEE EMERGENCY POWER PROGRAM/POSTULATED EVENT
1/89 8/89 1/90 3/90 5/90 8/90 1/91 4/91 5/91 12/91 3/92 KEOWEE ACB 600/
EP SINGLE FAILURE 208 VAC PROBLEM DBD OEP# ONMR 371 START 10/90 4KV SPARE RBS DBD MOTOR KEOWEE LEE EMERGENC OVERLOAD OF EEG EMERG.
POWER KEOWEE UNITDB DDD DBD 2 3oxy DEGRADED KOE DBD KOE GRID BKR PRE COORDINATION EDSFI SI TA RELAY/
OCONEE BREAKER XS2 SETTING COORDINATION STARTUP TRANSFORMERS AND
=
POSTULATED EVENT YELLOW BUS ZONE DIFFERENTIAL RELAY SETTING
=
PROGRAM 125 VDC DBD OCONEE EMERGENCY POWER SYSTEM PROGRAM/POSTULATED EVENT
CHRONOLOGY 06/86 SSFI ON EMERGENCY FEEDWATER SYSTEM DEFICIENCY NOTED IN DOCUMENTATION OF KEOWEE DYNAMIC ANALYSIS 08/86 DUKE DEVELOPED INTERNAL ACTION LIST OF CALCULATIONAL FILES TO BE REVIEWED FOR COMPLETENESS AND UPGRADED INCLUDING:
KEOWEE DYNAMIC ANALYSIS LEE DYNAMIC ANALYSIS
.MOTOR RELAYING STUDY 10/86 ECCW AND SSF EVENTS PROVIDED EMPHASIS DESIGN BASIS DOCUMENTATION EFFORT (DBD)
SELF-INITIATED TECHNICAL AUDIT (SITA)
TOPFORM 06/87 MOTOR RELAYING STUDY LER 269/87-05 POTENTIAL FOR HPI MOTOR TRIPPING ON LOCA/LOOP SSFI FOLLOW-UP NOT A PROBLEM UNTIL MDEFWP ADDITION 1979 REVIEW OF FUTURE MODS TO ASSESS IMPACT TO ELECTRICAL POWER SYSTEM (TOPFORM) 10/87 2 FUNCTIONAL UNITS OF EPSL REMOVED LER 269/87-09 (VOLUNTARY)
ONE STANDBY BUS REMOVED FOR MAINTENANCE TWO FUNCTIONAL EPSL UNITS REMOVED CONFLICT IN TECH SPECS - LCO ALLOWS REMOVAL OF STANDBY BUS BUT NOT TWO FUNCTIONAL UNITS TOTAL TIME WOULD HAVE BEEN WITHIN LCO TRAINING PACKAGES TECH SPEC INTERPRETATION PLANNED TECH SPEC CHANGE
02/88 CT-4 REMOVAL FROM SERVICE LER 269/88-04 NO EVENT - DESIGN REVIEW FROM 10/87 EVENT CONTROL POWER FUSES FROM SK-1, 2, ALSO POWER FOR RETRANSFER TO STARTUP LOGIC NORMAL REMOVAL OF SK-1, 2, REMOVED FUSES RENDERING LOGIC INOPERABLE INITIATED DESIGN STUDY OF MAINTENANCE PRACTICES SCHEDULED ELECTRICAL SITA
.INITIATED DESIGN CHANGES TO ADD FUSES 04/88 SWITCHYARD BREAKER FERRO-RESONANCE LER 270/88-02 SWITCHYARD BREAKERS REPLACED CONDITION OF FERRO-RESONANCE OCCURRED CERTAIN CONDITIONS COULD HAVE PREVENTED TRANSFER TO STANDBY NOT PREDICTABLE - NEW PHENOMENON TOPFORM PROGRAM WAS IN PLACE DE TRAINING INVESTIGATE EPSL MODEL 08/88 LOSS OF BOTH MAIN FEEDER BUSES LER 287/88-04 UNIT IN REFUELING ONE MFB OUT FOR MAINTENANCE SECOND MFB INADVERTENTLY TRIPPED DURING MOD TO ENHANCE LOAD SHED RESET CAPABILITY PROCEDURE DEFECTIVE NOT A SYSTEM DESIGN PROBLEM 09/88 LOSS OF POWER LER 287/88-05 UNIT IN REFUELING EPSL TESTING AT END OF REFUELING PROCEDURE/MANAGEMENT INADEQUACY NOT A SYSTEM DESIGN PROBLEM
03/89 SINGLE FAILURE POTENTIAL LER 269/89-06 NO EVENT - DESIGN IDENTIFIED SINGLE RELAY FAILURE COULD LOCKOUT E-1, 2 ON STARTUP SOURCE BUT NOT SWITCHYARD BREAKERS VOLTAGE WOULD BE SENSED ON STARTUP BUS, PREVENTING TRANSFER TO STANDBY ALL THREE UNITS MODIFIED 03/89 REACTOR TRIP LER 287/89-02 SWITCHYARD TRANSIENT RESULTED IN REACTOR TRIP NOT EMERGENCY POWER SYSTEM RELATED 06/89 STANDBY BREAKER POTENTIAL SINGLE FAILURE LER 269/89-09 PROCEDURE/TECH SPEC INADEQUACY CONDITION WHEN ONE STANDBY BUS OUT OF SERVICE - SUSCEPTIBLE TO SINGLE FAILURE RETRANSFER TO STARTUP BLOCKED SIMILAR RESULT FROM PROCEDURAL MITIGATION OF LEE PROBLEM TECH SPECS DO NOT ADDRESS THE REMOVAL OF ONE STANDBY BUS TIME LESS THAN 72 HOURS - CONSISTENT WITH STANDARD SPECS FOUND AS PART OF DESIGN BASIS DOCUMENTATION 06/89 POWER STANDBY BUS FROM CENTRAL LER 269/89-10 IF STANDBY BUS POWERED FROM CENTRAL RATHER THAN LEE DEGRADED VOLTAGE WOULD NOT TRIP SL-1, 2 FOLLOW-UP FROM LEE SITUATION WOULD HAVE BEEN IDENTIFIED AS PART OF DESIGN BASIS DOCUMENTATION NO PAST OPERABILITY CONCERN
08/89 RBS MOTOR 2B LER 270/89-06 SPARE MOTOR WAS INSTALLED IN 1980 WITHOUT CHANGING RELAY SETTING RELAY COULD HAVE TRIPPED MOTOR UNDER WORST CASE VOLTAGE AND LOADING CONDITIONS RBS MOTOR 2A WAS STILL AVAILABLE ACCEPTABLE SUBSTITUTE PROGRAM WAS INITIATED IN 1988 THAT PROVIDES EVALUATION OTHER SPARE MOTORS WERE EVALUATED, TAGGED, AND PROCEDURES REVISED OTHER DUKE PLANTS NOTIFIED IDENTIFIED AS A RESULT OF 4 KV DBD 09/89 SWITCHYARD ISOLATION PUSHBUTTON LER 269/89-14 STATION PROCEDURES DID NOT REQUIRE SWITCHYARD ISOLATE PUSHBUTTON TO BE PLACED IN A TEST POSITION WHEN CERTAIN SWITCHYARD PCB's WERE BEING TESTED THIS HAD THE POTENTIAL FOR MAKING THE OVERHEAD. PATH INOPERABLE FOR ALL THREE UNITS DURING LOOP UNDERGROUND PATH WAS NOT IMPACTED DISCOVERED BY OPERATIONS PERSONNEL AFTER COMPLETION OF EMERGENCY POWER SYSTEMS TRAINING PROCEDURES WERE REVISED TO INCLUDE THIS REQUIREMENT REMOVAL AND RESTORATION OF OTHER AUXILIARY ELECTRICAL SYSTEM PROCEDURES WERE REVIEWED BY DESIGN ENGINEERING MODIFICATION WAS PERFORMED TO ENHANCE SWITCHYARD ISOLATE CIRCUIT 03/90 DEGRADED GRID LER 269/90-04 AND LER 269/90-05 230 KV SWITCHYARD VOLTAGE DEGRADED BELOW THE ANALYZED MINIMUM VOLTAGE OF 219 KV COULD HAVE BEEN PERMITTED TO POWER THE UNIT AUXILIARIES
10/88 LEE CIRCUIT TRANSIENT CAPABILITY LER 269/88-13 FOLLOW-UP FROM SSFI 1979 ADDITION OF MDEFW PUMPS REDUCED MARGIN REVISED PROCEDURES - REQUIRED S BREAKERS IN MANUAL, INOPERABILITY OF STANDBY BUSES INITIATED DESIGN CHANGE 01/89 CABLE SEPARATION LER 269/89-04 DISCOVERED AS A RESULT OF FIRE DAMAGE NOT A FUNCTIONAL PROBLEM CABLES DID NOT MEET FSAR COMMITMENTS INITIATED REVIEW OF CABLES/ROUTING AND DESIGN DOCUMENTATION 01/89 TEST PROCEDURE LER 270/89-01 STANDBY BUSES ENERGIZED FROM CENTRAL 2 EVENTS STANDBY BUS IN LCO PROPERLY BUT FAILED TO DO REDUNDANT PATH TESTING SPECIAL TEST PERFORMED.AND DID NOT HAVE S BREAKER SWITCHES IN MANUAL DIRECT RESULT OF LEE INOPERABILITY 02/89 REACTOR TRIP LER 270/89-02 INSTALLING MOD TO CORRECT 2/88 EVENT PERSONNEL ERROR/MANAGEMENT DEFICIENCY CREATED GROUND/OTHER EXISTING ON EHC SYSTEM NOT A SYSTEM DESIGN PROBLEM
03/90 DEGRADED GRID (continued)
SETTING OF E BREAKER AND EGTPS RELAYING WERE NOT ADEQUATE CONSIDERING MINIMUM ANALYZED SWITCHYARD VOLTAGE POTENTIAL FOR TRIPPING OF INDIVIDUAL SAFETY RELATED LOADS POTENTIAL FOR MAKING OVERHEAD PATH FROM KEOWEE UNAVAILABLE NOTIFIED OTHER DUKE PLANTS
.IDENTIFIED AS A RESULT OF 230 KV DBD ADDED A SECOND LEVEL OF DEGRADED GRID PROTECTION INITIATED RELAY SETTING DOCUMENTATION/
JUSTIFICATION EFFORT 08/90 KEOWEE OVERLOAD LER 269/90-12 SINGLE FAILURE COULD OVERLOAD KEOWE E GENERATORS - IF KEOWEE UNITS WERE GENERATING TO GRID PRIOR TO ACCIDENT, COULD RESULT IN LOSS OF BOTH GENERATORS GENERATION TO GRID WAS PROHIBITED TILL PROBLEM WAS FIXED ADDED LOGIC AND TIME DELAY IN KEOWEE ACB I &
ACB 2 AND PCB9 IDENTIFIED BY KEOWEE EMERGENCY POWER DBD 01/91 KEOWEE ACB SINGLE FAILURE LER 269/91-01 SINGLE FAILURE IN KEOWEE UNDERGROUND ACB's THAT COULD RESULT IN TIEING BOTH KEOWEE GENERATORS TOGETHER MAY CAUSE DAMAGE TO.GENERATORS MODIFIED ACB CONTROL CIRCUIT IDENTIFIED AS A RESULT OF A REVIEW OF OPERATING EXPERIENCE REPORT (INPO) COUPLED WITH KEOWEE DESIG.N BASIS DOCUMENTATION EFFORT
04/91 KEOWEE BREAKER COORDINATION LER 269/91-03 BREAKER COORDINATION PROBLEM THAT COULD HAVE RENDERED THE AUXILIARY POWER FOR A KEOWEE UNIT INOPERABLE IN THE EVENT OF A FAULT ON A NON-SAFETY RELATED EQUIPMENT CORRECTED PROBLEM BY REMOVING BREAKERS AND CHANGING SOME BREAKER SETTINGS NOTIFIED OTHER DUKE PLANTS IDENTIFIED BY RELAY SETTING/BREAKER COORDINATION DOCUMENTATION EFFORT 05/91 230KV SWITCHYARD RELAY SETTING LER 269/91-04 RELAY SETTING OF ZONE. PROTECTION DIFFERENTIAL RELAYS FOR UNIT I STARTUP TRANSFORMER AND THE YELLOW BUS WERE SET INCORRECTLY POTENTIAL FOR INADVERTENTLY TRIPPING AND LOCKING OUT THESE PIECES OF EQUIPMENT IF A FAULT OCCURRED ON ADJACENT NON-SAFETY RELATED EQUIPMENT UNDERGROUND PATH WAS NOT IMPACTED RELAY SETTINGS WERE CHANGED NOTIFIED OTHER DUK E.PLANTS IDENTIFIED AS A RESULT OF RELAY SETTING/
BREAKER COORDINATION DOCUMENTATION EFFORT 05/91 MCC XS2 BREAKER COORDINATION LER 269/91-07 BREAKER COORDINATION PROBLEM THAT COULD HAVE CAUSED MCC XS2 TO TRIP ON A FAULT ON A NON-SAFETY RELATED PANELBOARD TWO OTHER POWER SYSTEM STRINGS WOULD STILL HAVE BEEN AVAILABLE AND FULLY CAPABLE OF MITIGATING ACCIDENT BUT VULNERABLE TO SINGLE FAILURE PANELBOARD WAS REMOVED FROM THE SAFETY BUS NOTIFIED OTHER DUKE PLANTS IDENTIFIED AS A RESULT OF RELAY SETTING/
BREAKER COORDINATION DOCUMENTATION EFFORT
CORRECTIVE ACTIONS SSFI FOLLOW-UP - ELECTRICAL COMPLETE TOPFORM - IMPLEMENTED SITA MAINTENANCE PRACTICE DESIGN STUDY COMPLETE TECH SPEC CLARIFICATION - COMPLETED DBD CABLE INVENTORY TRAINING - DE AND ONS EPSL - COMPUTER MODEL TECH SPEC REWRITE EFFORT - TO BE SUBMITTED MID 92 DOCUMENT RELAY SETTING PRE-EDSFI SITA - SCHEDULED FOR 03/92 IPE SUBMITTAL
STATION MODIFICATIONS MOTOR RELAY SETTINGS - COMPLETE PCB CAPACITOR CHANGES - COMPLETE CONTROL POWER FUSING - COMPLETE CABLE SEPARATION - UI COMPLETE EPSL SINGLE FAILURE - COMPLETE LEE UPGRADE - COMPLETE SWITCHYARD ISOLATION ENHANCEMENT MODIFICATION COMPLETE DEGRADED GRID MODIFICATION - COMPLETE KEOWEE OVERLOAD MOD - COMPLETE RELAY SETTING CHANGES - COMPLETE BREAKER CHANGEOUT - COMPLETE KEOWEE ACB CONTROL CIRCUIT MOD - COMPLETE UNDERVOLTAGE ON CT5 - ONGOING
SUMMARY
OF SELF INITIATED TECHNICAL AUDIT SITA-89-01 EMERGENCY POWER DISTRIBUTION SYSTEM Conducted from June 19, 1989 through September 11, 1989.
Involved Design Engineering Department, the Oconee Nuclear Station, the Lee Steam Station, and Keowee Hydro-Electric Station.
Purpose was to assess the operational readiness and functionality of Oconee's Emergency Power Distribution System (EPDS), including the Emergency Power Switching Logic.
Items identified:
12 - Findings 8 - Audit follow-up Items 11 -- Document discrepancies 9 - Observations 2 - Recommendations.
Only 3 items remain OPEN: I Finding and 2 Audit Follow-up items.
The open finding deals with improvement in management attention. direction, and monitoring of action items identified in engineering studies, technical reports, and task force,-reports.The resolution to this item was considered satisfactory however the item will be re-evaluated during future SITA audits. One follow-up item is awaiting the completion of a Design Study which is scheduled for completion in October of 1992. The other item deals with the resolution of LER 269/89-09. This resolution involves the clarification of Technical Specification 3.7, "Auxiliary Electrical Svstems." The clarification for the LER related item has been complete, however, the Technical Specification is undergoing a rewrite and is scheduled for submittal in mid 1992.
OCONEE COMPLETED DBD'S 230 KV Switchyard Structures CCW Structures Keowee Structures Fire Protection Emergency Feedwater CCW System High Pressure Injection System Component Cooling Service Air Instrument Air Control Room A/C 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 Design Basis Events (plant level)
OCONEE DBD 1992-95 PROJECTED SCHEDULE 1992 1993 Cable Tray Supports Auxiliary Building Transformer/Switchgear Enclosure Turbine Building Reactor Bldg/Unit Vent (91-92)
Tornado/Wind Seismic SSF Keowee 125VDC power Nuclear Instrumentation Integrated Control System 125VDC SSF Power 120VAC Vital I&C Power 600/208/120 VAC SSF Power 4160VAC SSF Power Control Rod Drive Reactor Coolant Fire Detection Coolant Treatment ASP/Loss of Control Room Coolant Storage Recirculated Cooling Water System Class (plant level)
Gas Waste Disposal Feedwater Auxiliary Steam Condensate SSF Potable Water Radwaste Facility SSF Diesel Air High Pressure Service Water SSF Diesel Service Water Containment Isolation SSF HVAC Low Press in/Core Flood SSF Aux Service Water Low Press Service Water SSF HVAC Service Water RB Spray SSF RC Makeup Spent Fuel Cooling Pent Room Ventilation RB Ventilation RB Cooling Vacuum Main Steam (92-93)
SSF (92-93)
Single Failure
OCONEEDBD 1992-95 PROJECTED SCHEDULE 1994 1995 Flooding ISFSI Missiles Area Radiation Monitoring Evacuation Alarm Plant Computer Meteorological Instr Process Radiation Monitoring Reactor Coolant Pump Monitor LIq Waste Disp Hydrogen Purge RWF HVAC.
Fuel Oil RB Purge Lube Oil N2 Purge Breathing Air Chem Add/Sample SSF C02 Aux Bldg Vent Steam Bleed Spent Fuel Vent Pipe Rupture
IPE SUBMITTAL DECEMBER 1990 Corrective Actions Due to "Loss Of Power" Contribution to Risk SSF Operator Action SSF Job Task Analysis - determine feasibility of enhancing performance of required actions.
Actions Complete -
procedural enhancements for manning the SSF have been made.
SSF Simulator - determine feasibilty of constucting and training on SSF control board simulator.
Complete -
determined that sufficient training and familiarization can be accomplished with OJT-type training in the actual SSF control room.
SUMMARY
HIGHER NUMBER OF REPORTABLE ITEMS OF POSTULATED EVENTS HAVE OCCURRED THAN DESIRED.
MOST HAVE LITTLE SAFETY SIGNIFICANCE.
MOST IDENTIFIED THROUGH SELF-INITIATED PROGRAMS.
HEIGHTENED UNDERSTANDING OF SYSTEM AMONG DESIGNERS AND STATION PERSONNEL.
SYSTEM REMAINS FLEXIBLE AND RELIABLE.