ML20168A564
| ML20168A564 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1979-002-00 | |
| Download: ML20168A564 (4) | |
Text
B-587 PRECURSOR DESCRIPTION AND DATA NSIC Accession Number: 147399 Date: March 22, 1979
Title:
Both Diesel Generators Unavailable at Kewaunee The failure sequence was:
- 1. With the reactor at full power, diesel generator lB was removed from service for maintenance.
- 2. During the testing of diesel 1A, manual speed control was lost due to excessive wear to the bronze pinion in the syncho-notor gear housing.
The pinion damage was caused by improper gear alignment and failure of a governor limit switch.
Corrective action:
The pinion and limit switch were replaced and adjusted and the diesel generator was tested and returnr4 to service.
Design purpose of failed system or component:
The diesel generators provide power to safety-related equipment when offsite power and the unit generator are unavailable.
Unavailability of system per WASH 1400: *Emergency power:
1 x 10- 2 1D Unavailability of component per WASH 1400: *Diesel generator:
3 x 10-2 /D Unavailabilities are in units of per demand D-1.
Failure rates are in units of per hour HR-1.
Reactor at Power Diesel Generator and Diesel Gen-lA Fails to Run erator lB Removed Due to Loss of From Service for Manual Speed Maintenance Control -
A Result of a Worn Pinion in the Synchro-Motor Gear Housing and a Failed Limit Switch Potential Severe Core Damage No -
No loop No td' NSIC 147399 -
Actual Occurrence for Both Diesel Generators Unavailable at Kewaunee
/
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 Clo::,ure Cooling House toads Potential Severe Core Damage Sequence No.
_______________________________________No No No Yes Yes No No Yes 2
3 4
5 6
7 8
9 10 11 12 13 00 Yes No Yes
-LIU NSIC 147399 -
Sequence of Interest for Both Diesel Generators Unavailable at Kewaunee
- Not included in operating procedures
B-590 CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER: 147399 DATE OF LER: March 22, 1979 DATE OF EVENT: February 21, 1979 SYSTEM INVOLVED: Emergency power COMPONENT INVOLVED: Diesel generator CAUSE:
Excessive wear on pinion In synchro-gear motor housing plus failed limit switch SEQUENCE OF INTEREST: Loss of offsite power ACTUAL OCCURRENCE:
Unavailability of two diesel generators while at power REACTOR NAME:
Kewaunee DOCKET NUMBER:
305 REACTOR TYPE:
PWR DESIGN ELECTRICAL RATING: 535 M~We REACTOR AGE: 5.0 yr VENDOR: Westinghouse ARCHITECT-ENGINEERS: Flour Power OPERATORS: Wisconsin Public Service Corp.
LOCATION:
27 miles East of Green Bay, Wisconsin DURATION:
4(a) hours PLANT OPERATING CONDITION:
100% power SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate perform nce; (b) failed to start; (c) made inoperable; failed to run DISCOVERY METHOD:
Testing COMMENT: