ML20168A563
| ML20168A563 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1975-020-00 | |
| Download: ML20168A563 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
108078 Date:
November 14, 1975
Title:
Auxiliary Feedwater Pump Flows Restricted at Kewaunee The failure sequence was:
- 1. Resin beads were leaking from a mixed-bed demineralizer in the makeup water system and travelling to the condensate storage tank..-
- 2. During a unit startup, AFW pumps IA and lB suction strainers became clogged with resin beads, resulting in low pump flow.
- 3. The turbine-driven AFW pump (1C) suction strainer was also clogged, which resulted in low flow from that pump also.
Corrective action;
- 1. The condensate storage tank and the pump suction strainers were cleaned and returned to service.
- 2. At a later date the fine mesh strainers were to have been removed.
Design purpose of failed system or component:
- 1. The auxiliary feedwater pumps provide water to the steam generators for reactor cooling in the event the main feedwater system is not operable.
Unavailability of system per WASH 1400: lkauxiliary feedwater:
2.5 X 10-4 (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:
- strainers not included pumps, failure to start:
1 x 10-3 /D pumps, failure to run:
3 x 10-5 /hr Unavailabiliries are in units Of per demand D-1.
Failure rates are in units of per hourHR-1.
Unit in Mixed-bed Reduced auxiliary Reduced auxiliary startup demineralizer feedwater flow feedwater flow operations leaking resin from IA and lB from 1C turbine-beads to con-motor-driven AFW driven ANW pumip densate storage pumps due to due to suction tank suction strainers strainer clogged I
clogged with resin Iwith resin Potential Severe Core Damage No -
Main feedwater pumps operable No No No NSIC 108078 -
Actual Occurrence for Auxiliary Feedwater Pump Flows Restricted at Kewaunee
ot Reactor Auxiliary P0W PR rHigh JLong Term IPotential Sequence Trip Feedwater and Demanded POV soa Pressure oeSvr o
.water Secondary tion Valve Injection Cooling Core Heat Removal Closure Damage No 1
No 2
Yes 3
Yes 4
No 5
No 6
110.
Yes Yes 7
No 9
No 10 L
-Yes11 (F)
Yes12 Yes 13 NSIC 108078 -Sequence of Interest for Auxiliary Feedwater Pump Flows Restricted at Kewaunee
- not included in mitigation procedures
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER:
108078 DATE OF LER:
November 14, 1975 DATE OF EVENT:
November 5, 1975 SYSTEM INVOLVED:
Auxiliary Feedwater COMPONENT INVOLVED:
AFW Pump Strainers CAUSE:
Strainers clogged with resin beads SEQUENCE OF INTEREST:
Loss of feedwater ACTUAL OCCURRENCE:
Inoperable AFW pumps during plant start-up REACTOR NAMtE:
Kewaunee DOCKET NUMBER:
50-305.
REACTOR TYPE:
PWR DESIGN ELECTRICAL RATING:
535 MWe REACTOR AGE:
1.9 yr VENDOR:
Westinghouse ARCHITECT-ENGINEERS:
Pioneer Services OPERATORS:
Wisconsin Public Service Corp.
LOCATION:
27 injnes east of Greenbay, Wisc.
DURATION:
36t0(a) hours PLANT OPERATING CONDITION:
Plant startup SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate performance;, (b) failed to start; 0
made inoperable; (d) _______
DISCOVERY METROD: during operation COMMENT:
-