ML18029A273
| ML18029A273 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 11/15/1984 |
| From: | Domer J TENNESSEE VALLEY AUTHORITY |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8411200275 | |
| Download: ML18029A273 (6) | |
Text
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RESULATORY~IFORNATION DISTRIBUTION SYEN (RIBS)
ACCESSION NBR;e411200275 Doc ~ DATE: 84/11/15 NOTARIZED; YES DOCKET FACIL:50-259 Browns Ferry Nuclear Power Stations Unit 1< Tennessee 05000259 50 260 Browns Ferry Nuclear Power Stations Unit 2< Tennessee 05000260 50 296 Browns Ferry Nuc,lear, Power Stations. Unit 3< Tennessee 05000296 AUTH BYNAME AUTHOR AFFILIATION DOMERr J ~ A ~
Tennessee Valley Authority RECIP,NAME RECIPIENT AFFILIATION DENTON~H ~ Rs Office of Nuclear Reactor Regul ationi Director
SUBJECT:
Forwards Page 8~4 of Vol 1 of 841031 1 tr on App R
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10CFR50're fire protection. Page inadvertently omitted from submittal'ISTRIBUTION CODE A006D "COPIES RECEIVED L'TR ENCL'IZEB TITLE! OR Submittal 'ire Protection NOTES:NMSS/FCAF 1cy. icy NMSS/FCAF/PM'L:06/26/73 NMSS/FCAF. 1cy, 1cy NMSS/FCAF/PM, OL:06/2e/74 NMSS/FCAF icy, icy NMSS/FCAF/PM, OL 07/02/76 05000259 05000260 05000296 INTERNALB RECIPIENT ID CODE/NAME NRR ORB2 BC 01 ACRS 11 ELD/HDS4 IE/NHITNEYe L NRR NAMBACH NRR/DL 0 IR RGN2 COPIES LTTR ENCL 3
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TENNESSEE VALLEYAUTHORITY CHATTANOOGA, TENNESSEE 37401 400 Chestnut Street Tower II November 15, 1984 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Dear Mr. Denton:
In the Matter of the Tennessee Valley Authority Docket Nos. 50-259 50-260 50-296 Please refer to L. M. Mills'etter to you dated October 31, 1984 regarding Appendix R to 10 CFR 50, Fire Protection, for our Browns Ferry Nuclear Plant.
Enclosed is page 8-4 of volume 1 which was inadvertently omit;ted from t;he October 31 submittal.
If you have any questions, please get in touch with us through the Browns Ferry Project; Manager.
Very truly yours, TENNESSEE VALL Y AUTHORITY Subscribed a
.> me this d sworn to efore day of ames A. Domer Nuclear Engineer 1984.
Notary Public My Commission Expires 0/'T Enclosure cc (Enclosure):
U.S. Nuclear Regulatory Commission Region II ATTN:
James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. R. J. Clark Browns Ferry Project Manager U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue
'Bethesda, Maryland 20814 5 841119 05000259 PDR ADOCK An Equal Opportunity Employer
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4.
Exception The walls that separate the turbine building and each unit's reactor building provide 3-hour fire rated separation between redundant safe shutdown equipment and are in compliance with Section III.G.2 except for the doors into the main steam and feedwater piping tunnels.
These doors are identified as number 32 (unit 1),
36 (unit 2),,and 50 (unit 3) on drawings 47W216-4 and -7 (see Volume 2, Tab 4) and have no fire endurance ratings..
Justification The walls, floors, and ceilings of the main steam and feedwater piping tunnels are reinforced concrete and exceed 3-hour fire-rated construction.
There are no fixed combustibles in the pipe tunnels.
(See Browns Ferry Nuclear Plant FSAR, Figures 12.2-4, 12.2-6, 12.2-44, and 12.2-45 for general arrangement of the pipe tunnels.)
For the thermal effects of a fire in a turbine building to propagate to its corresponding reactor building the fire would have to breach a blowout panel at the turbine building end of the tunnel, make a 34-foot vertical drop, and then travel 75 feet horizontally to the blowout panels at the turbine building-reactor building interface.
The fire would have to breach this blowout panel, proceed for another 28-feet horizontally, and then make a vertical drop of 18 feet to reach the identified door opening on elevation 565 of the reactor building. It is TVA's position that a turbine building fire could not propogate to redundant equipment in the reactor building through the main steam and feedwater piping tunnel.
A fire in the reactor building (elevation 565) would have to propagate along this same path, except in reverse order.
In addition, the 565 elevation of the reactor buildings is provided with a pre-action suppression system actuated by cross-zoned ionization smoke detectors.
It is TVA's position that a reactor building fire will not propagate to the turbine building through the main steam and feedwater piping tunnel.
The turbine buildings and reactor buildings are also provided with Class III standpipe and hose systems designed in accordance with NFPA 14 and portable extinguishers installed in accordance with NFPA 10.
Replacing doors with numbers 32, 36, and 50 with 3-hour fiie-rated doors would not significantly enhance the fire protection features of the reactor building or turbine building.
Therefore, TVA requests an exemption from the requirement to have 3-hour fire-rated doors in the identified openings.
5.
Exemption, Intervening CombustiblesSection III.G.2.b requires separation of redundant trains by a horizontal distance of more than 20 feet with no intervening combustibles.
Contrary to this requirement, the reactor buildings have open ladder-type cable trays located between redundant cables that will be separated by more than 20 feet.
Insulation on cables in these trays is considered an intervening combustible.
Justification To be finalized upon completion of discussions between TVA and NRC.
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