ML20168A740
| ML20168A740 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1974-LTR | |
| Download: ML20168A740 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
91676 Date:
May 17, 1974
Title:
Malfunction of Auxciliary Feedwater Pumps at Turkey Point 3 The failure sequence was:
- 1. With the reactor at power, an attempt was made to start all three auxiliary feedwater pumps.
- 2. Two of the pumps failed to start due to overtightened packings.
- 3. The third pump failed to start due to a turbine regulating valve pneumatic controller malfunction.
Corrective action;
- 1. The packing on the "A" AFW pump was loosened and later replaced.
After replacement, a sticking governor linkage was also discovered.
- 2. The "B" A91 pump was repacl-ed.
- 3. The."C" AFW pump governor was exercised and its pneumatic controller output signal was increased in value.
Design purpose of failed system or component:
- 1. The auxiliary feedwater system provides feedwater to the steam generators for reactor cooling when main feedwdter is unavailable.
Unavailability of system per WASH 140G:*
Auxiliary feedwater system:
2.5 x 1lO4 (start + 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />)
Unavailability of component per WASH 1400:*
pump, failure to start: 1
- 10-3/D
- Unavailabilitieq are in units of per demand D-1. Failure rates are in units of per hour HR-'.
of Reactor Auxiliary PORV PORV or High Long Term Potential Sequence Tri Fedater and DeanV PORV ola-Pressure Core Severe No.
'ater Secondary tion Valve Injection Cooling Core Heat Removal Closure Damage No 1
No 2
Yes 3
Yes 4
No 5
No 6
Yes 7
rYes 8
No 9
No 10 LA Yes11 Yes 12 Yes 13 NSIC 91676 -
Sequence of Interest for Malfunction of Auxiliary Feedwater Pumps at Turkey Point 3
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NU~MBER:
91676 DATE OF LER:
May 17, 1974 DATE OF EVENT:
May 8, 1974 SYSTEM INVOLVED:
Auxiliary feedwater COMPONENT INVOLVED:
Auxiliary feedwater pumps CAUSE:
Overtightened packings, turbine regulating valve pneumatic controller malfunction human maintenance error SEQUENCE OF INTEREST:
Loss of feedwater ACTUAL OCCURRENCE:
Failure of three auxiliary feedwater pumps to start, and run during testing.
REACTOR NAME:
Turkey Point 3 DOCKET NUMBER:
50-250 REACTOR TYPE:
PWR DESIGN ELECTRICAL RATING:
693 MWe REACTOR AGE:
1.9 yr VENDOR:
Westinghouse ARCHITECT-ENGINEERS:
Bechtel OPERATORS:
Florida Power & Light Co.
LOCATION:
- Z5. miUesa.outh_: of Miami, Fla.
DURATION:
360(a) hours PLANT OPERATING CONDITION:
At 98% power SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate performance; nbfailed to start; (c) made inoperable; (d) __________
DISCOVERY METHOD:
During testing COMMENT:
The three ANW pumps which failed to start also provide auxiliary feedwater to Unit 4.