ML20085G000
| ML20085G000 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 11/09/1973 |
| From: | Eric Thomas TENNESSEE VALLEY AUTHORITY |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| AO-BFAO-7332W, NUDOCS 8308240149 | |
| Download: ML20085G000 (3) | |
Text
I i
m (n)
( )
- ~
v LJ t
j TENNESSEE VALLEY AUTHO AlW r-sq-i CHATTANOOGA, TENNESSEE.
/c 37401'L t
/ <m s
}
(
l Ei.~
.a November 9, 1973 e tg SM'h'8%Pe"Z PAATNEASHIP p
j B
p'*,(
s R 6,.o Q
e cm N v m s73 - #;i 1 Mr. John F. O'Icary, Director E-Z Directorate of Licensing L Sjk,'
g Office of Regulation
.c.' of
/,<, # #
- )
U.S. Atomic Energy Cc iscion Washington, DC 20545
!w,,,0 i~
Dear Mr. O' Lear /:
TE:!!IESSEE VALIEY AUTHCRITY - BRCk'::S FEa.Tl NUCLEAR PUJiT U:IIT 1 -
DOCKET !!0 50-259 - FACILITY CPERATII G LICE:!SE DPR AEN0EAL OCCURRE:;CE REPCZD EFAG-7332'd The enclosed report is to provide details concerning an FFCI condensate j
healer low level criten calfunction which occurred on Erowns Ferg Nuclear Plcat unit 1 on October 31, 1973, and is submitted in cecordance with Appendix A to Regulatog Guide 1.16, Revision 1, Cetober 1973 Very tr21y yours, TEli::ESSEE VALLEY !.UTHORITY I,
7 T,
,sd/O nu i
E. F. Thena.s Director of Pcwer Production Enclosure CC (Enclosure):
l Mr. Ilomen C. Moseley, Director Region II Regulatory 0 3 rations Office, USAEC 230 Peachtree Street, 157 Atlanta, Georgia 30303 49 731109 l
S M 05000259 f
l PDR l
' ]!
l i
\\
8100 i
COPY SENT REGTON
[
(_ _
_q y.-
O O
ABNOK4AL CCCURRE: ICE REPORT Beport Ilo.--EFAO-7332W Report Date--:fovember 9,1973 Occurrence Date--October 31, 1973 Facility--Browns Ferry Ituelear Plant Identification of Occurrence Unit 1 HPCI condensate header low level switch calfunction.
Conditions Prior to Occurrence Reactor at 30-percent power, 300 MWe, during startup test program.
Description cf Cecurrence During accelerated surveillanco testing on October 31, 1973, level switch IS-73-56A was found to operate outside technical specification trip level setting, Table 3 2.3, of equal to or greater than elevation 551 feet.
Ievel switch B was tested i= ediately and operated properly. A simple' adjustment of spring tensica made switch IS-73-56A operable. The switches are Robertshaw Model 83481 levelac level switches.
Analysis of Occurrence The level switches are arranged in a one out of two logic. Either switch will initiate transfer of the EPCI suction fro = the condensate storage tank to the suppressica chamber.
If required, transfer would have been initiated by the redundant switch.
Corrective Action The vendor representative was called in to detemine the cause of the continued switch malfunctions. Theinitialswitcheswereratedat1/4 ampere /250Vd-c.
They were replaced with switches rated at 1/2 a= pere /250V d-c.
(See letter from -
J. E. G111 eland to F. E. Kruesi, Director, Directorate of Regulatory Operations, AEC, dated July 18,1973.)
l Investigationindicatedthatthe1/2-ampereswitchcontactswerenotcompatible with the trip mechanism. Specifically, the new switch required a greater travel and greater pressure by the mechaniss to operate the contacts. The original type of switches will be installed as soon as they can be obtained and are
- 'suppressors installed around the level switch load to prevent arcing of these s
i contacts. An accelerated testing frequency of once a week has been initiated l
for both switches. This test frequency will apply to the interim period with
[
l l
j L
$I
u y-O O.
-e-the 1/2-c= pere switches and to the 1/4-c= pere switches until three consecutive tests have been accomplished satisfactorily en a weekly basis. The testing frequency vill then be increased to biveekly and the orig nal test schedule i
of once a month will ^ce recumed after three consecutive tests have been satisfactorily perfomed on the biveekly frequency.
i Failure Data Robertshaw Model 83481 Ievelac level switch. Serial numbers: Switch A--D-73-Io176; Switch B--D-73-Io160 Switch Date Failure Corrective Action
~
LS-73-56B 6/18/73 Switch contacts /
Installed higher current failed [
rating contacts IS-73-56B 8/16/73 Failed to operate Readjusted switch mechanism IS-73-56A and B 10/17/73 Failed to operate Readjusted switch mechanism a
a I
I i
\\
k b
b
'I