ML20168A445
| ML20168A445 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1978-020-00 | |
| Download: ML20168A445 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
137543 Date:
April 13, 1978
Title:
Diesel Generator Fails to Start Following a Loss of All Offeite Power at Calvert Cliffs 1 The failure sequence was:
- 1. With the plant shutdown, switchyard breaker protective relaying automatically opened the switchyard breakers, resulting in a loss of offsite power.
- 2. Diesel generator 11 failed to start.
- 3. Diesel generator 12 started and provided power to safety-related loads.
Corrective action:
None -
the cause of the diesel-generator failing to start was not determined.
Design purpose of failed system or component:
- 1. Off site power provides the preferred source of power to safety-related equipment when the unit generator is not operating.
- 2. The diesel-generators provide a standby source of power to safety related loads when neither the unit generator nor offsite power is available.
Unavailability of system per WASH 1400:
- off site power:
2 x 10-5/hr onsite power:
1 X 10 2/1)
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
With the Reactor Diesel-Generator 11 Diesel-Generator 12 Shutdown, Switchyard Fails to Start Starts and Provides Breaker Protection Power to Safety-Relaying Automatically Related Loads Opened Breakers, Resulting-in a Loss of Off site Power Potential Severe Core Damage
-No - steam driven auxiliary feedwater system available for reactor cooling at RCS temperatures above n,25OPF.
NSIC 137543 - Actual Occurrence for Diesel Generator Fails to Start Following a Loss of All Offaite Power at Calvert Cliffs 1
L~,ss of Turbine Emer-Auxiliary PORV PORV or High Long Offsite Generator gency Feedwater and Demanded PORV Isola-Pressure Term Power Runs Back Power Secondary Ition Valve Injection Core and Assumes Heat Removal Closure Cooling House Loads Severe Core Damage Sequence No.
2 3
4 5
6 7
8 9
10 11 12 13 NSIC 137543 -
Sequence of Interest for Diesel Generator Fails to Start Following a Loss of All Off site Power at Calvert Cliffs 1 Not included in mitigation procedures.
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER:
137543 DATE OF LER: April 14, 1978 DATE OF EVENT:
April 13, 1978 SYSTEM INVOLVED:
off site power, onsite power COMPONENT INVOLVED: diesel generator CAUSE:
failure to start SEQUENCE OF INTEREST:
loss of off site power ACTUAL OCCURRENCE:
loss of offsite power while shutdown REACTOR NAME:
Calvert Cliffs 1 DOCKET NUMBER:
50-317 REACTOR TYPE:
PWR DESIGN ELECTRICAL RATING:
845 MWe REACTOR AGE:
3.5 yr VENDOR:
Combustion Engineering ARCHITECT-ENGINEERS:
Bechtel OPERATORS:
Baltimore Gas & Electric Co.
LOCATION:
40 miles south of Annapolis, Nd.
DURATION:
N/A PLANT OPERATING CONDITION:
shutdown SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate perfornance;(afailed to start; (c) made inoperable; (d)
DISCOVERY METHOD:
during operation COMMENT:-