ML20168A439
| ML20168A439 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1977-001-00 | |
| Download: ML20168A439 (5) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
121533 Date:
January 4, 1977
Title:
Two Diesel Generators Trip at Brunswick 1 The failure sequence was:
- 1. A complete loss of offaite power test was underway with all four diesel generators starting.
- 2. Diesel generators 3 and 4 soon tripped however for reasons unspecified.
The lock out relays were reset and diesel generators 3 and 4 operated properly.
- 3. About 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> later a subsequent test was carried out in which diesels 2, 3, and 4 tripped. The problem was traced to low lube oil pressure and temperature switches.
Corrective action:
- 1. The setpoint for the lube oil pre-filter heater was increased from 150'F to 2300F.
- 2. The setpoint for the jacket water system heater was increased from 180OF to 2000F.
- 3. The setpoint for the low Li~be oil pressure switch time de~lay was changed from 30 sec to on~e inute.
(See next page)
Design purpose or faile system or component:
Emergency power provide a.c. power to the plant when offsite sources are unavailable.
Unavailability of system per WASH 1400:
Emergency Power:
10-I/D Unavailability of component per WASH 1400: Diesel Engine failure to run:
3 x 10-4/hr lUnavallabilities are In units of per demand D-1.
Failure rates are in units of per hour HR-1.
Corrective action:
(continued)
- 4. The diaphragms in the pre-lube/pre-filter valves were found to be broken on units 3 and 4. This prevented heated lube oil from being circulated to the diesel lube oil sump.
All 4 Diesels Start Numbers 3 and 4 The Lock Out Relays Were Approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> An Orderly Shutdown During Complete Diesels Trip Reset And The Diesels Later The Diesels Was Initiated To Loop Test Within 1 Min Start and Operate Pro-Were Tested Again Investigate The perly Diesels With Units Problem 2, 3, and 4 Trip-ping Potential Severe Core Damage No NSIC 121533 -
Actual Occurrence of Two Diesel Generators Trip at Brunswick 1
Loss of Reactor Diesel Reactor Made Sub-RCIC/HPCI ADS/LPCI Long Offsite Scram Start and critical by the Initiates Cs Term Power Load SBLCS Or Rods Are Initiates Core Manually Driven In Cooling Potential Severe Core Damage Sequence No.
No Yes No Yes Yes No Yes Yes No Yes No Yes Yes Yes "Yes 1
2 3
4 5
6 7
8 9
10 11 12 13 14 15 NSIC 121533 -Sequence of Interest for Two Diesels Trip at Brunswick 1
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER: 121533 DATE OF LER:
January 18, 1977 DATE OF EVENT:
January 4, 1977 SYSTEM INVOLVED:
Emergency Power COMPONENT INVOLVED:
Diesel Generators CAUSE:
Mechanical failure, design error SEQUENCE OF INTEREST:
Loss of offsite power ACTUAL OCCURRENCE:
Two Diesel Generators Trip at Brunswick 1 REACTOR NAME:
Brunswick 1 DOCKET NUMBER:
50-325 REACTOR TYPE: BWR DESIGN ELECTRICAL RATING:
821 MWe REACTOR AGE:
0.2 yr VENDOR:
General Electric ARCHITECT-ENGINEERS:
United Engineers & Constructors OPERATORS:
Carolina Power and Light LOCATION:
Three miles N of Southport, NC DURATION:
360 (a) hrs.
PLANT OPERATING CONDITION:
76% rated power SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate performance; (b) failed to Start; (c) made inoperable; nd3 failed to run DISCOVERY METHOD: testing COMMENT: