ML20168A452
| ML20168A452 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1979-058-00 | |
| Download: ML20168A452 (4) | |
Text
B-697 PRECURSOR DESCRIPTION AND DATA NSIC Accession Number: 153333 Date: November 15, 1979
Title:
Flowpath from AFW Pump to Two Steam Generators Made Inoperable at Cook 1 The failure sequence was:
With the reactor at 100% power and the turbine driven AEW pump out of service for repair, the motor control center which provides power for valves which direct flow from one motor-driven AFW pump to two of the four steam generators was removed from service for inspection.
Corrective action:
The motor control center was returned to service.
Design purpose of failed system or component:
The motor control center provides power to the two motor operated valves associated with the AFW flow path from the motor-driven AFW pumps to two of the four steam generators.
Unavailability of system per WASH 1400: *AEW (loss of net + 8 hrs): 2.5 x 1-Unavailability of component per WASH 1.400: -
Unavailabilities are in units of per demand UD Failure rates are in units of per hour HR-'
Reactor at 100% Power Supply for Valves Potential Power with Turbine- from Motor-Operated AFW Severe Driven AFW Pump Pump to Two of Four Gore Damage Out of Service Steam Generators Removed from Service for Inspection
.1.
No - Flowpath from one motor-operated AFW pump to two steam generators still available plus no loss of feedwater.
- No 0%
NSIC 153333 - Actual Occurrence for Flowpath from AFW Pump to Two Steam Generators Made Inoperable at Cook 1
Potential Sequence Severe No.
Core Damage No 1 No 2 Yes 3 Yes 4 No 5 No to 6
Yes 7 Yes 8 No 9
-No 10
.Yes 11
.Yes 12 Yes 13 NSIC 153333 - Sequence of Interest for Flowpath from AFW Pump to Two Steam Generators Made Inoperable at Cook 1
B-700 CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER: 153333 DATE OF LER: November 29, 1979 DATE OF EVENT: November 15, 1979 SYSTEM INVOLVED: Auxiliary Feedwater COMPONENT INVOLVED: Motor Operated Valves CAUSE: Motor Control Center removed from service for inspection while the turbine-driven AFW pump was out of service for repair, human error SEQUENCE OF INTEREST: loss of of feedwater ACTUAL OCCURRENCE: unavailability of two AFW system valves plus the turbine driven AFW pump REACTOR NAME: Cook 1 DOCKET NUMBER: 50-315 REACTOR TYPE: PWR DESIGN ELECTRICAL RATING: 1054 MWe REACTOR AGE: 4.8 yr VENDOR: Westinghouse ARCHITECT-ENGINEERS: American Electric Power Corp.
OPERATORS: -Indiana and Michigan Electric Co.
LOCATION: 11 miles south Of Benton Harbor, Michigan DURATION: 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> PLANT OPERATING CONDITION: 100% power SAFETY FEATURE TYPE OF FAILURE: (a) inadequate performance; (b) failed to start; 5
lc~ýjmade inoperable; (d)____________
DISCOVERY METHOD: operator observation COMMENT: The Cook 1 FSAR states the LOFW analysis for Cook 1 assumes flow to all four steam generators. The failure reported herein resulted in flow to only two steam generators.