ML20168A440
| ML20168A440 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1975-005-00 | |
| Download: ML20168A440 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
102146 Date:
April 9, 1975
Title:
Loss of Offsite Power at Brunswick 2 The failure sequence was:
- 1. The plants 1A and 2A 230kv buses had been incorrectly tied together.
- 2. With the reactor in cold shutdown, a single phase to ground fault caused the lockout relays for busses 1A and 2A to trip.
- 3. The diesels started and loaded as expected.
- 4. The relays were reset and of fsite power restored (,,4 min).
Corrective action:
This problem was corrected.
Design purpose of failed system or component:
The off site power source provides power to the plant when the unit generator isn't functioning.
Unavailability of system per WASH 1400:*
Unavailability of component per WASH 1400: *maintenance error:
3 x 10-3 /D Unavailabilities are in units of per demand D-1.
Failure rates are in units of per hour HR-1.
Reactor in cold Diesels start and shutdown, when phase load as expected to ground fault trips breakers Potential Severe Core Damage I
________________No No -
core in cold shutdown NSIC 102146 -
Actual Occurrence of Loss of Offsite Power at Brunswick 2
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 JInitiates Core Manually Driven In jCooling 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 102146 -
Sequence of Interest for Loss of Offsite Power at Brunswick 2
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER:
102146 DATE OF LER:
April 9, 1975 DATE OF EVENT:
March 26, 1975 SYSTEM INVOLVED:
Electric power COMPONENT INVOLVED:
relays CAUSE:
improper tying together of the 1A and 2A 230kv buses, human error SEQUENCE OF INTEREST:
loss of offsite power ACTUAL OCCURRENCE:
loss of offsite power REACTOR NAME:
Brunswick 2 DOCKET NUMBER:
50-32 4 REACTOR TYPE:
BWR DESIGN ELECTRICAL RATING:
821 MWe REACTOR AGE:
.05 yr VENDOR:
GE ARCHITECT.-ENGINEERS:
United Engineers, and Constructors OPERATORS:
Carolina Power and Light LOCATION:
3 miles N of South Port, NC DURATION:
N/A PLANT OPERATING CONDITION:
cold shutdown SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate performance; (b) failed to start; (0made inoperable; (d)
DISCOVERY METHOD:
operation COMMENT-
-