ML15261A292
| ML15261A292 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 01/27/1989 |
| From: | Ernst M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Tucker H DUKE POWER CO. |
| References | |
| NUDOCS 8902070101 | |
| Download: ML15261A292 (17) | |
See also: IR 05000269/1988034
Text
ACCELERATED
DISTRIBUTION
DEMONSTRATION
SYS'TEM
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:8902070101
DOC.DATE: 89/01/27
NOTARIZED: NO
DOCKET #
FACIL:50-269 Oconee Nuclear Station, Unit 1, Duke Power Co.
05000269
50-270 Oconee Nuclear Station, Unit 2, Duke Power Co.
05000270
50-287 Oconee Nuclear Station, Unit 3, Duke Power Co.
05000287
AUTH.NAME
AUTHOR AFFILIATION
ERNST,M.L.
Region 2, Ofc of the Director
RECIP.NAME
RECIPIENT AFFILIATION
TUCKER,H.B.
Duke Power Co.
SUBJECT: Forwards enforcement conference summary re Insp Repts
50-269/88-34,50-270/88-34 & 50-287/88-34..
DISTRIBUTION CODE: IE01D COPIES RECEIVED:LTR L
ENCL
SIZE:
TITLE: General (50 Dkt)-Insp Rept/Notice of Violation Response
NOTES:
RECIPIENT
COPIES
RECIPIENT
COPIES
ID CODE/NAME
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NRR/PMAS/ILRB12
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NOTE TO ALL "RIDS" RECIPIERT:
S
PLEASE HELP US 'ID REDUCE wASTE!
ONACT THE DOCUMENT CDNTROL DESK,
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TOTALNUMBER OF COPIES REQUIRED:
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ENCL
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Docket Nos. 50-269, 50-270, 50-287
'
63
License Nos. DPR-38, DPR-47, DPR-55
Duke Power Company
ATTN:
Mr. H. B. Tucker, Vice President
Nuclear Production Department
422 South Church Street
Charlotte, NC 28242
Gentlemen:
SUBJECT:
ENFORCEMENT CONFERENCE SUMMARY
(NRC INSPECTION REPORT NOS. 50-269/88-34, 50-270/88-34 AND
50-287/88-34)
This letter refers to the Enforcement Conference held at our request on
January 6, 1989.
This meeting concerned activities authorized for your Oconee
facility.
The issues discussed at this conference related to the inadequate
design of the Lee Station transmission system.
A brief summary, a list of
attendees,
and a copy of your handout are enclosed.
We are continuing our
review of these issues to determine the appropriate enforcement action.
In accordance with Section 2.790 of the NRC's "Rules of 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,
Malcolm L. Ernst
Acting Regional Administrator
Enclosures:
1. Enforcement Conference Summary
2. List of Attendees
3. Handout
cc w/encls:
M. S. Tuckman, Station Manager
State of South Carolina
bcc w/encl:
NRC Resident Inspector
DRS Technical Assistant
H. Pastis, NRR
Document Control Desk
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ENCLOSURE 2
LIST OF ATTENDEES
U. S. Nuclear Regulatory Commission
J. P. Stohr, Acting Deputy Regional Administrator
C. W. Hehl, Deputy Director, Division of Reactor Projects (DRP)
E. W. Merschoff, Deputy D.irector, Division of Reactor Safety (DRS)
G. R. Jenkins, Director, Enforcement and Investigation Coordination Staff
(EICS)
V. L. Brownlee, Branch Chief, DRP
T. E. Conlon, Section Chief, DRS
F. Jape, Section Chief, DRS
P. H.* Skinner, Senior Resident Inspector, Oconee, DRP
B. R. Bonser, Project Engineer, DRP
B. Uryc, Enforcement Coordinator, EICS
P. J. Fillion, Reactor Inspector, DRS
Duke Power Company
H. B. Tucker, Vice President Nuclear Production
M. Tuckman, Station Manager, Oconee
R. L. Swiegart, Superintendent of Operations, Oconee
R. C. Futrell, Manager, Nuclear Safety Assurance
R. L. Gill, Techical System Manager, Regulatory Compliance
R. L. Dobson, Electrical Engineer Manager, Oconee
B. L. Peele, Division Project Manager, Design Engineering
E. LeGette, Shift Supervisor, Compliance
J. E. Stoner, Jr., Engineering Consultant
D. Deatherage, Operations
ENCLOSURE 1
ENFORCEMENT CONFERENCE SUMMARY
On January 6, 1989, representatives from Duke Power Company (DPC) met with the
NRC in the Region II office in Atlanta, Georgia to discuss the inadequate
design of the Lee Station transmission system.
Following the opening. remarks by J. P. Stohr,
NRC,
Acting Deputy Regional
Administrator.,
DPC gave a presentation (see Enclosure 3) which addressed.NRC
concerns on the subject listed above.
The DPC presentation covered a system
description, sequence of events, a root cause discussion, corrective action,
and safety significance.
The NRC is presently considering enforcement action on this issue.
This
meeting served to enhance Region II's understanding of the issue and DPC's
corrective actions.
ENCLOSURE 3
OCONEE NUCLEAR STATION
LEE COMBUSTION TURBINE POWER CIRCUIT
NRC ENFORCEMENT CONFERENCE
JANUARY 6, 1989
AGENDA
LEE COMBUSTION TURBINE POWER CIRCUIT
- INTRODUCTION
- SYSTEM DESCRIPTION
- SEQUENCE OF EVENTS
- ROOT CAUSE DISCUSSION
- CORRECTIVE ACTIONS
- SAFETY SIGNIFICANCE
- SUMMARY
INTRODUCTION
LEE COMBUSTION TURBINE POWER CIRCUIT
VOLTAGE ON THE STANDBY BUSES WHEN POWERED
FROM LEE WAS UNACCEPTABLE FOR SUPPLYING
THE INRUSH OF 3 UNIT LOOP O.R 1 UNIT LOCA WITH
2 UNIT LOOP
EVENT IDENTIFIED BY DUKE AS PART OF FOLLOW-UP
ACTIONS FROM SSFI
LEE WAS DECLARED INOPERABLE UPON PRELIMINARY
DETERMINATION
CORRECTIVE ACTION SHOULD RESTORE LEE TO FULL
OPERABILITY BY MARCH 1989
OVER 50 ITEMS WERE IDENTIFIED BY DUKE
INTERNALLY FOR FOLLOW-UP FROM SSFI.
THIS WAS THE LAST ELECTRICAL ITEM.
SYSTEM DESCRIPTION
LEE COMBUSTION TURBINE POWER CIRCUIT
OCONEE EMERGENCY POWER SOURCE IS KEOWEE
HYDRO STATION
-2 HYDRO-ELECTRIC GENERATORS
-2 TRANSMISSION PATHS TO STATION
- OVERHEAD THRU 230 KV SWITCHYARD
- UNDERGROUND VIA BURIED CABLE
- TECH SPECS FOR ALL THREE UNITS DEPEND ON KEOWEE
LEE COMBUSTION TURBINE IS A BACKUP IN CERTAIN
CONDITIONS
-1 KEOWEE INOPERABLE > 72 HOURS (45 DAYS/3 YEARS)
- LOSS OF ALL 230 KV TRANSMISSION LINES (24 HOURS)
- PLANNED INOPERABILITY OF BOTH KEOWEE
<72 HOURS
- UNPLANNED INOPERABILITY OF BOTH KEOWEE
<24 HOURS
- KEOWEE STEPUP TRANSFORMER INOPERABLE
> 72 HOURS (28 DAYS)
DESCRIPTION OF LEE
- LEE STEAM STATION IS LOCATED APPROXIMATELY
30 MILES FROM OCONEE
-3 COMBUSTION TURBINES AVAILABLE
- 100 KV TRANSMISSION LINE THAT CAN BE ISOLATED TO
SUPPLY ONLY OCONEE
- TRANSFORMER CT-5 DIRECTLY SUPPLIES STANDBY BUSES
VIA BREAKERS SL-1 AND SL-2
- NO AUTOMATIC. ALIGNMENT OF LEE - MUST BE MANUALLY
STARTED, TRANSMISSION LINE MUST BE MANUALLY
ALIGNED, SL-1, 2 MUST BE MANUALLY CLOSED, NOT A
QUICK START OPERATION
- ONCE ALIGNED TO STANDBY BUSES, EMERGENCY POWER
SYSTEM IS AUTOMATIC AND IMMEDIATELY AVAILABLE
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TRAINING US
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SEQUENCE OF F 7ENTS
LEE COMBUSTION TURBINE POWER CIRCUIT
1967
LEE COMBUSTION TURBINES COMMITTED AS AN
ALTERNATE EMERGENCY POWER SOURCE
- NO SUPPORTING TRANSIENT CALCULATIONS
DOCUMENTED IN FILES
- IN RETROSPECT, SYSTEM WOULD HAVE FUNCTIONED
1979
MOTOR DRIVEN EMERGENCY FEEDWATER PUMPS (6)
ADDED TO STATION FOLLOWING TMI
- NO CALCULATIONS WERE PERFORMED ON LEE
TRANSIENT ADEQUACY
- IN RETROSPECT, SYSTEM BECAME INOPERABLE
6/86
NRC PERFORMED A SSFI ON EMERGENCY FEEDWATER
SYSTEM
- DEFICIENCY NOTED IN DOCUMENTATION OF KEOWEE
DYNAMIC ANALYSIS
8/86
DUKE DESIGN DEVELOPED AN 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
RESPONSE TO NRC CONTAINED COMMITMENT
TO REVIEW ELECTRICAL AND MECHANICAL
SYSTEM CALCULATIONS FOR COMPLETENESS
6/87
KEOWEE DYNAMIC ANALYSIS AND MOTOR
RELAY ANALYSIS COMPLETED
POTENTIAL FOR HPI PUMP TRIPS DUE TO
EXTENDED DEGRADED VOLTAGE IN SOME
CIRCUMSTANCES
WITH CHANGES, THE KEOWEE SUPPLY WAS
ACCEPTABLE AND IT WAS ASSUMED THAT LEE
WAS O.K.; GIVEN LOWER PRIORITY
10/17/88
PRELIMINARY CALCULATIONS COMPLETED ON
LEE INDICATING UNACCEPTABLE VOLTAGE FOR
3 UNIT LOOP OR I LOCA WITH 2 LOOP
-LEE DECLARED INOPERABLE
- NRC RED PHONE REPORT
- OPERATIONS PROCEDURE CHANGED
10/21/88
FINAL CALCULATION COMPLETED
11/16/88
LER 269/88-13 SUBMITTED
12/15/88
TECH SPEC CHANGE SUBMITTED
01/06/89
NRC REGION II MEETING
ROOT CAUSE
LEE COMBUSTION TURBINE POWER CIRCUIT
ORIGINAL DESIGN IN 1967 DID NOT DOCUMENT
TRANSIENT ANALYSIS
QUALITY OF DESIGN CALCULATION FILES NOT TO
PRESENT STANDARDS
MODIFICATION IN 1979 DID NOT CONSIDER LEE
TRANSIENT ANALYSIS
- QUITE POSSIBLE THAT IT WOULD HAVE BEEN
CONSIDERED IF ORIGINAL ANALYSIS WAS
DOCUMENTED IN 1967
SAFETY SIGNIFICANCE
LEE COMBUSTION TURBINE POWER CIRCUIT
LEE IS USED INFREQUENTLY AS A BACKUP EMERGENCY
POWER SOURCE
POTENTIAL IS FOR TRIPPING ONE OR MORE MOTORS
DURING THE INITIAL PHASES OF LOOP OR LOOP AND
3 UNIT LOOP
- LOW PROBABILITY EVENT (MULTIPLE OFFSITE LINES)
PROBABILITY OF EVENT AT TIME WHEN LEE WAS IN
OPERATION WAS EVEN LOWER
- STATION IS ANALYZED FOR LOSS OF ALL AC POWER
- STANDBY SHUTDOWN FACILITY IS ANOTHER BACKUP
FOR LOOP
- LOW PROBABILITY EVENT
- PROBABILITY OF EVENT AT TIME WHEN LEE WAS IN
OPERATION WAS EVEN LOWER
- LOCA LOADS COME ON IN 11 SECONDS
- LOOP LOADS COME ON IN 31 SECONDS
- IF LOCA AND LOOP ARE OFFSET BY APPROXIMATELY
1 MINUTE SYSTEM WOULD HAVE FUNCTIONED
CONCLUSION - SIMULTANEOUS OCCURRENCE OF A LOCA
ON ONE UNIT WITH A CONCURRENT LOOP ON THE OTHER
TWO UNITS WHILE RELYING ON LEE TO ENERGIZE THE
STANDBY BUSES IS EXTREMELY LOW PROBABILITY AND
THE INCREMENTAL RISK IS CONSIDERED NEGLIGIBLE.
CORRECTIVE ACTIONS
LEE COMBUSTION TURBINE POWER CIRCUIT
LEE COMBUSTION TURBINE SYSTEM DECLARED INOPERABLE
INCIDENT PROMPTLY REPORTED TO NRC
OPERATING INSTRUCTIONS WERE PROMPTLY ISSUED
TO OPERATION
OPERATIONS PROCEDURES FOR LOSS OF POWER AND THE
100 KV POWER SUPPLY WERE REVISED
FURTHER ANALYSES WERE PERFORMED WHICH JUSTIFIED
TWO OCONEE UNITS SHOULD IT BE NECESSARY
PROPOSED AMENDMENT TO TECHNICAL SPECIFICATIONS
WAS SUBMITTED
MODIFICATION DESIGNED TO RESOLVE ISSUE - TO BE
INSTALLED BY MARCH 1989 ON ALL THREE UNITS
TOPFORM PROGRAM FOR DESIGN ENHANCEMENT
IMPLEMENTED IN 1987
- REVIEWED PROGRAM AND DETERMINED TOPFORM
WOULD PROVIDE REASONABLE ASSURANCE TO PREVENT
THIS EVENT
- TOPFORM REQUIRES PERIODIC REVIEW OF CALCULATION
FILES
-
TOPFORM REQUIRES ENHANCED DESIGN DOCUMENTATION
- TOPFORM REQUIRES MORE CROSS DISCIPLINARY REVIEWS
OF DESIGN CHANGES
- CONTINUED SELF EVALUATIONS SUCH AS SELF INITIATED
TECHNICAL AUDITS WILL PROVIDE ASSURANCE THAT WE
MEET OUR DESIGN BASIS
SUMMARY
LEE COMBUSTION TURBINE POWER CIRCUIT
DESIGN DEFICIENCY IDENTIFIED WITH LEE TRANSMISSION
LINE AS A RESULT OF DUKE INTERNAL FOLLOW-UP
FROM NRC SSFI INSPECTION
COMPLETION OF SSFI FOLLOW-UP ACTION PLANS PROVIDES
ADDITIONAL ASSURANCE OF THE OPERABILITY OF THE
STATION
SSFI FOLLOW-UP ACTIONS HAVE IDENTIFIED THREE
REPORTABLE SITUATIONS - LEE COMBUSTION TURBINE,
HPI OVERCURRENT SETTINGS AND HPI PIGGYBACK MODE
OF OPERATION
CORRECTIVE ACTIONS TO SSFI IN GENERAL AND TO THIS
SITUATION IN PARTICULAR WERE PROMPT AND
COMPREHENSIVE AND WENT BEYOND THE REQUIREMENTS
OF THE SSFI
NORMAL SURVEILLANCE OR QUALITY ASSURANCE
ACTIVITIES WOULD NOT HAVE DETECTED THIS SITUATION
THE PROBABILITY OF THE CIRCUMSTANCES OCCURRING
WAS EXCEPTIONALLY LOW
CORRECTIVE ACTION PRESENTLY UNDERWAY
CURRENT DESIGN METHODS SHOULD PREVENT THIS TYPE
OF SITUATION