ML20168A468
| ML20168A468 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1979-013-00 | |
| Download: ML20168A468 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
148892 Date:
February 22, 1979
Title:
Diesel Generator Sequencer Found in Test Mode at Farley 1 The failure sequence was:
- 1. With the plant at 94% power, diesel generator lB preventive maintenance.
- 2. The 1-2A diesel generator sequencer was found to that diesel generator inoperable.
The sequencer faulty switch mechanism.
was removed from service for be in the test mode, rendering was in the test mode due to a Corrective action:
The sequencer was returned to operation and the faulty switch mechanism repaired.
Design purpose of failed system or component:
The sequencer provides control signals for load shedding and load sequencing in connection with diesel generator starting and loading.
Unavailability of system per WASH 1400:
- Electric power:
1 x 16-2 /D Unavailability of component per WASH 1400:
- Diesel generator:
3 x 10-'/D Unavailabilities are in units of per demand D-1.
Failure rates are in units of per hour HR-1
Reactor at Diesel Generator Diesel Generator 94% Power lB Removed from 1-2A Inoperable Due Service for Pre-to its Sequencer ventive Maintenance Being in the Test Mode as a Result of a Faulty Switch Potential Severe Core Damage No -
no loss of offsite power NSIC 148892 -
Actual Occurrence for Diesel Generator Sequencer Found in Test Mode at Farley 1
Loor of Turbitie Emer-Auxiliary PORV PORV or High Long Gffsite 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 No Sequence No.
2 3
4 5
6 7
8 9
10 11 12 13 NSIC -
148892 -
Sequence of Interest for Diesel Generator Sequencer Found in Test Mode. at Farley 1 success requires operator action to transfer loads to a smaller, river water pump diesel generator.
- not included in mitigation procedures.
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER:
148892 DATE OF LER:
March 22, 1979 DATE OF EVENT:
February 22, 1979 SYSTEM INVOLVED:
Emergency power COMPONENT INVOLVED:
Diesel generator sequencer CAUSE:
Sequencer in test mode due to faulty switch SEQUENCE OF INTEREST:
Loss of off site power ACTUAL OCCURRENCE:
Sequencer in test while other diesel generator was unavailable REACTOR NAME:
Farley 1 DOCKET NUMBER:
50-348 REACTOR TYPE:
PWR DESIGN ELECTRICAL RATING:
829 MWe REACTOR AGE:
1.5 yr VENDOR:
Westinghouse ARCHITECT-ENGINEERS:
Bechtel/SSI OPERATORS:
Alabama Power Co.
LOCATION:
24 miles.SE of Dothan, Alabama DURATION:
24(a) hours PLANT OPERATING CONDITION:
94% power SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate performance; (b) failed to start; (D
made inoperable; (d) ____________
DISCOVERY METHOD:
Operator observation COMMENT:
-