ML20116N298
| ML20116N298 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 11/18/1992 |
| From: | Orser W DETROIT EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-92-001, IEB-92-1, NUDOCS 9211230306 | |
| Download: ML20116N298 (2) | |
Text
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Novenber 18, 1992 NRC-92-0127 U. C. Nuclear Regulatory Commission Attn Document Control Deck Washington, D. C.
20555 Referencecs 1)
Fermi 2 NRC Docket T 50-341 NRC L'.cence N.
NPF-43 2)
NRC Eulletin No. 92-01, " Failure of Thetme-Lag 330 Fit e Barrier Systet-to Maintain Cabling in Wide Cable Trays and Small Conduits Free From Fire Damage", dat ed June 24, 1992.
- 3) Detroit Edison Let ter to NRC, " Detroit Edison Response t o NRC Bulletin 92-01", NRC-92-0091, daeed July 73, 1992
- 4) NRC Bulletin No. 92-01, suppleme t 1. " Failure of Thermo-Lag 330 fire Barrier System to Perform its Specified Fire undurance Function", dated Au6ust 26, 1992
- 5) Detroit Edison Letter to NRC, " Detroit Ediscn Response to NRC Bu11et3n 92-01, Supplement 1,"
NRC-92-0116, dat cd September 3C,1992 Subj ect :.
Additional Information on Detroit Edison Response to'NRC Bulletin 92-01, Supplement 1 The purpose of this.etter is to provide additior,al information on Detroit Edison's response to Bulletin 92-01, Supplement 1 (Reference 5).
Our response' stated that the rmall. HVAC toom (Fire Zone 9) located directly above the computer room on elevation 677' 6" (whick serves as a' HVAC chase) where the combustible loading is extreme'.y low doer not have an artcoatic fire detection system.
However, an automatic fire detection system is provided in other areas-of the I1re Zone 9 below this 'small room.
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U Sh'RC 1;ov ecibe r 18, 1992 1:RE-?2-0127 rage 2 A question wac received from the 1;PE regarding the reocons for not having a f ir e detex tion ryotea f or the cmall HVAC toom.
The followirg i r.
the explanation why this rocm does not need a fire cetection c y c t er..
o There are no expored combustiblec in thin t o oti. Fence, a fire involving in situ c ombuc cibleo is not postulated for this area.
The stor age of combustibles in thic area is not pos t ul a t ed o
because t he r oom is connec t ed wit h r on-cotabust ible taet al ductwork with little floor space available for any storage and the exist ing adminiott ative controle do not per mit any stutage in thin area.
Therefore, even if a fire detetion syrtem was installed in this coa 11 room it would not be expect ed to activat e due to the lack of potential for a fire.
The areount of The ino-Lag 330-1 taterial uned in the 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rct ed fir e m c nsicts of two cua11 asseul>1ien wall enclosing +M s2}
(a p p r ox in.a t el y It pieced at the top of t he wall it celf.
Speci fically, the Thermo-Lag is not uced t o pr ovide livisional oeparation, rather it is in place t o ceal two small gaps between t he top of the block wall and the ceiling of the room.
Because these assemblies ate inst alled in the top of the wall and there are no expeced combuutibles in the cua11 room, flame propagation into or out of this amall room is not postuland.
Additionally, since this room is consider ed a part of the control room (Fire Zone 9), alternate safe shutdown capabilities are expected to be used if evacuation of the control roon is required due to a fire.
If you have any questione, plesce contac t Mt. Girij S. Shukla at
'313) 586-4270.
Sincerely.
0 Ww cc:
E. Bradley (NUMARC)
T. G. Colburn A. B. Davic M. P. Fhillips S. Stasek J. Silberg (Shaw, Fittman, Pe tto & Trowbridge)
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