ML20168A580
| ML20168A580 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1979-LTR-00 | |
| Download: ML20168A580 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
153167 Date:
September 26, 1979
Title:
Gas Turbine Power Supplies Fail at Oconee The failure sequence was:
- 1. With Units 1 and 2 at approximately 100% power, both Keowee Hydro units were removed from service for repair and a Lee Steam Station gas turbine started to provide power to the standby buses.
- 2. The Lee Station gas turbine repeatedly tripped during operation, resulting in unavailability of power to the standby buses.
Corrective action:
Investigation revealed no reason for the gas turbine's tripping.
Proce-dures were revised to reqt ire immediate shutdown of the Oconee Units in the event the Keowee Hydro Units are out of service and the Lee Station Turbine trips.
Design purpose of failed system or component:
The Lee Steam Station Gas Turbines are used to provide power to the Oconee standby buses in the event the normal source of emergency power, the Keowee Hydro units, are removed from service for maintenance.
Unavailability of system per WASH 1400:
- on-site electrical power:
1 x 10-2 /D Unavailability of component per WASH 1400:
- not considered Unavailabilities are in units of per demand D.
Failure rates are in units of per hour HR'*.
Reactor at Keowee Hydro Units Lee Steam Station Approximately Removed from Service Gas Turbine 100% Power for Repair Repeatedly Trips, Resulting in Repeated Loss of Power to the Standby Buses Potential Severe Core Damage 4
No -
no Loop No 1140 NSIC 153167 -
Actual Occurrence for Gas Turbine Power Supplies Fail at Oconee
Loss of Turbine Emer-Auxiliary PORV PORV.or High Long Offsite Generator gency Feedwater and Demanded PORV Isola-Pressure Term Power Runs Back Power Secondary tion Valve Injection Core and Assumes Heat Removal Closure Cooling House Loads Potential Severe Core Damage Sequence No.
No No Yes Yes Yes No Yes 2
3 4
5 6
7 8
9 10 11 12 13 i
(F)
Yes No Yes III-NSIC 153167 -
Sequence of Interest for Gas Turbine Power Supplies Fail at Oconee
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER:
153167 DATE OF LER:
October 1, 1979 DATE OF EVENT:
September 26, 1979 SYSTEM INVOLVED:
emergency power COMPONENT INVOLVED:
gas turbine generator CAUSE:
repeated generator trips SEQUENCE OF INTEREST:
loss of offsite power ACTUAL OCCURRENCE:
loss of standby power source during power operation REACTOR NAME:
Oconee 1 and 2 (Oconee 3 in cold shutdown)
DOCKET NUMYBER:~ 50-26 9 and 50-2 70 REACTOR TYPE:
PWR DESIGN ELECTRICAL RATING:
887 MWe REACTOR AGE:
6.4 yr (Oconee 1)
VENDOR: B&W ARCHITECT-ENGINEERS:
DPC/Bechtel OPERATORS:
Duke Power Co.
LOCATION:
30 miles west of Greenville, SC DURATION:
2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> PLANT OPERATING CONDITION:
both plants at approximately 100%/ power SAFETY FEATURE TYPE OF FAILURE: (9inadequate performance; (b) failed to start; (c) made inoperable; (d) ____________
DISCOVERY METHOD:
operational event COMMENT: -