ML20168A443
| ML20168A443 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1979-050-00 | |
| Download: ML20168A443 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
150271 Date:
June 19, 1979
Title:
Both RIIR Service Water Pumps Inoperable at Brunswick 2 The failure sequence was:
- 1. The reactor was operating at 88% power.
- 2. The operator gave a mechanic clearance to uncouple 2B RHR pump for alignment check.
- 3. Mechanic uncoupled pump 2A by mistake.
Corrective act ion:
Seven hours later the error was discovered and pump 2A was recoupled and tested to ensure operability.
Design purpose of failed system or component:
Th~e RHR provides reactor core cooling and water level control during normal and scrammed shutdown periods.
The RHR can also be operated in the LPCI mode.
Unavailability of system per WASH 1400:
- 1.1 x 10-4 /D Unavailability of component per WASH 1400:
- 3 x 10-3 /D operator error I
Unavailabilities are in units of per demand D-1.
Failure rates are in units of per hour HR'*.
With the reactor at 88%
Mechanic uncouples pump 2A power, the operator gives by mistake, leaving both clearance to uncouple RHR pumps out of service for pump 2B for alignment 7 days check Potential Severe Core Danage No -
normal operation &
HPCI in service.
No NSIC 150271 -
Actual Occurrence of Both RHR Service Water Pumps Inoperable at Brunswick 2
Potential Sequence Severe No.
Core Damage No1 Yes 2
No 3
Yes 4
Yes 5
Yes 6
Yes 7
NSIC 150271 -
Sequence of Interest of Both RHR Service Water Pumps Inoperable at iFor success the operator must rack the pumps backin within 2-24 hours.
Brunswick 2
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER:
150271 DATE OF LER:
July 12, 1979 DATE OF EVENT:
June 19, 1979 SYSTEM INVOLVED:
RHR COMPONENT INVOLVED:
service water pumps CAUSE:
human error SEQUENCE OF INTEREST:
loss of feedwater ACTUAL OCCURRENCE:
Both RHR service water pumps inoperable at Brunswick 2 REACTOR NAME:
Brunswick 2 DOCKET NUMBER:
50-324 REACTOR TYPE:
BWR DESIGN ELECTRICAL RATING:
821 MWe REACTOR AGE:
4.25 yr VENDOR:
GE ARCHITECT-ENGINEERS:
United Engineers and Constructors OPERATORS:
Carolina Power and Light LOCATION:
Three miles N of South Port, NC DURATION:
7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> PLANT OPERATING CONDITION:
88% power SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate performance; (b) failed to start; Onade inoperable; (d)
DISCOVERY METHOD: operator surveillance COMMENT:
-