ML20137M361
| ML20137M361 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 01/21/1986 |
| From: | Jens W DETROIT EDISON CO. |
| To: | Adensam E Office of Nuclear Reactor Regulation |
| References | |
| VP-86-0002, VP-86-2, NUDOCS 8601280243 | |
| Download: ML20137M361 (3) | |
Text
- -___
Wape H. Jeu
%wWa@W Nuclear Operahons Detroit On <ra;rthDueHighway 6400 No
o " *
u ci.a, Operations January 21, 1986 VP-86-0002 Director of Nuclear Reactor Regulation Ms. Elinor G.
Adensam, Chief Licensing Branch No. 1 Division of Licensing U.
S.
Nuclear Regulatory Commission Washington, D.
C.
20555
Dear Ms. Adensam:
,1
Reference:
1)
Fermi 2 NRC Docket No. 50-341 I
NRC License No. NPF-43 2)
Detroit Edison to NRC Letter, " Design of Alternative Shutdown Approach", EF2-72001, October 22, 1984 3)
Detroit Edison to NRC Letter, " Submittal of Deviations from Staff Interpretations of Fire Protection Features in 10CFh50, Appendix R and Justification", EF2-72717, August 3, 1984 4)
Detroit Edison to NRC Letter, " Alternative Shutdown in the Control Center Complex",
EF2-72718, August 16, 1984 5)
Detroit Edison to NRC' Letter, " Alternative Shutdown System", VP-85-0221, January 3, 1986
Subject:
Alternative Shutdown System Reference 5 reported two instances in which cable routing i
was,recently found to deviate from Detroit Edison's commitments in Reference 2 to NRC's fire protection
~
requirements.
Following discovery of the second instance, Edison requested Impe11 Corporation to perform an independent review of the Alternate Shutdown System design.
,00 8601280243 860121 l
PDR ADOCK 05000
,1 F
p
,f
_ _ _ ~
Ms.
E.
G Adensam January 21, 1986 VP-86-0002 Page 2 This review identified a third instance in wh ic h required
( able is : outed in an alternate shutdown area.
The contio1 e i rc n i t s for three vaIves (Suppiession Chamber
[
Level Instrument Line Solenoid Isolation Valve EV-T50N412A; g
Torus Level In
- ii.i i ' i.
Ei leriid Irelat ion Vaisi 3
EV-F41F400; and solenoid valve E V - T 5 0 -- F 4 2 1 A, which controis air operated valve V5-2232 on the torus level instrument 1ine' run through Iire areas for which the Dedicated Shutdown Panel (H21-P623) is required.
Closur: of any one of the tbrce va1ves (EV-T50-N412A, EV-E41-F400 or EV-T50-F421A) would cause loss of torus level indication the Dedicated Shutdown Panel Torus level indication is on iequired for alternate shutdown, as specified in NRC Information Not ic e 84-09, and as commitred by Detroit Edison in Reference 2 and Fermi-2 FSAR Sect io "' '
/.
Detro t Fdisen'*
analysis i n d i c a t e t, tlat if a " hot s ti e r t "
occuried in the control c i rc u i t s for valves EV-T50-F412A EV-E41-F400, tbey might c1ose inadvertent 1y.
The procedure or for use of the Dedicated Shutdown Pane 1 in a fire requirea stripping the DC buses, which would deenergize these valves.
TI n
>?
?.
"1( t liit"
( or c<
- 1. fore tie valves sere deenergized, the valves could close and, f
b c( ause they fail "As-Is" on loss of power, they would not reopen after they were deenergized.
'; imilarly, if the control circuit for solenoid valve EV-T50-F421A short8 or is deenergized, this solenoid valve could
,ii's i
,u.,ing selv.
V5-2232 to close
(
Valve VS-2232 also closes on loss of air supply.
The Station Air S y 8 t e rb is not iequired for a1terna e ahutdown and is a s s i: m e d to be unavailable during iires requiriny use of the Dedicated Shutdewn Panel.
To correct these delicieneses, Det roi t Edison wilI reroute the torus level sensing 1ine to c on n ec t the torus level tiansmitter (C16-N405) to the torus side of air operated valve VS-2232.
This will eliminate concerns about inadvertent closure of V5-2232.
Detroit Edison also pinns to install local control capability for the two isolation valves ( E V -T 5 0 - F 412 A, and E V -- E 41 - F 4 0 0 )
on the torus level sensing 1ine Iic.' <mt io l 5 iii be provided through tiansfer switches and back1ighted r ii s h h u t t o r4 s t<>
be installed on Dedicated Shutdown Panel H21-P625.
The procedure for use of the Dedicated Shutdown Panel (Station Procedure 20.000.lH) will be revised to reflect tbese equipment changes.
~c-
-- 7 Ms. Elinor G. Adensam Janucry 21, 1986
^
VP-86-0002 Page 3 These actions will be completed prior to startup from the current outage.
These changes modify the fire protection program but do not decrease the level of fire protection from that described in the Final Safety Analysis Report through Amendment 60 and approved in the SER through Supplement No. 5.-
These changes do not result in a failure to complete the fire protection program approved by the Commission prior to license issuance nor do they involve an unreviewed safety question.
Hence, they may be made without prior approval of the Commission as allowed by License Condition 2.C.(9)(c).
Should you have any questions regarding this matter, please call Mr.
A.
E.
Wegele (313) 586-4210.
Sincere 7[f 2g cc:
Mr.
P.
M.
Byron Mr.
M.
D.
Lynch Mr.
C.
B.
Ramsey 4
+
4 e
_ _,