ML20101G024

Forwards Rev 3 to Calculation 2-FP-0085 Raceway & Firezone R Cable Supports Analysis, in Ref Re Fire Detection & Automatic Suppression Sys Coverage

ML20101G024
Person / Time
Site:	Comanche Peak
Issue date:	06/19/1992
From:	William Cahill, Walker R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20101G029	List: ML20101G024 ML20101G047
References
TXX-92301, NUDOCS 9206250264
Download: ML20101G024 (2)

Text

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h 5- Log # TXX-92301

=- = file # 909.5 MIELECTR/C June 19.-1992 Wmiam J. Cahill, Jr.

Group Vice Prendent U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washiny on, DC 20555

SUBJECT:

CbMANCHE PEAK STEAM ELECTRIC STATION (CPSES) - UNIT 2 DOCKET NO, 50-446-l ROCKBE TOS CABLE REF: TXX-92232 dated April 7, 1992,.from William J. Cahiil . Jr. t^ -the NRC, l-Gentlemen:

The NRC requested additional detail about the supports associated with one hour fire rated cable at CPSES As described in the reference correspondence,.both fire detection and automatic suppression system coverage are provided where one hour fire-rated cabling is installed, except for.three areas. These areas are:

1. Auxiliary Building (790') - Laundry Holdup Area,-

2. Safeguards Building (790') - Valve Room 2-066, and

3. Safeguards Building (790') ~ Stairwell.(Room 2-0',4A).

f . Pursuant to your ' request, the " Raceway and Fire- Zone R Cable Supports Analysis

• has been revised to-incorporete the.fol10 wing'.information about unprotected steel-cable trays and support elements: 1

1. Details of,the type and extent nf combustibles present in all plant areas'where one-hour' fire-rited' cable is installed,

2. Details of the administrative controls which effectively monitor and' limit combustibles in the subject areas,. and

3. Details of test dit associated with non-fire rated ' cables

-installed'in cab,< '. rays containing one hour fire-rated cable.

Consistent with the Unit 1 approach for evaluating exposed supports associated-with protected raceways and the guidance provided by Generic Letter 86-10,- this-analysis demonstrates'thelfollowing:

2400il i 9206250264 920619 6 gp P OR -- ADOCK 0500 400 N. Olive Street LB.8I l Dallas Temas 75201 ; k e ..

s TXX-92301 Page 2 of 2 o In all areas where one hour fire-rated cable is installed and which contain significant quantities of combustible materials, provision is made for fire detection and automatic suppression and administrative controls to ensure design basis fire induced temperatures will not exceed the critical temperature of the steel support mechanisms as defined by NFPA.

o In the three plant areas described above, where one hour fire-rcted cable is installed without automatic suppression, or provision for fire detection, the inherently low combustible loadi*) and administrative controls ensure that a design basis-fire will not result in high enough temperatures to jeoperdize the integrity of unprotected cable support mechanisms.

Enclosed is the calculation performed documenting the evaluation. The appropriate areas of the Fire Protection Report are being revised to reflect the above information. If you should have any questions, please call Mr. J. D. Seawright at (214) 812-4375.

Sincerely, h* . )

• William J. Cahill, Jr.

By: M b.

Roger D. Walker Manager of Regulatory Affairs for NE0

, JDS/tg Enclosure c- Mr. R. D. Martin, Region IV Resident Inspectors,-CPSES (2)

Mr. B. E. Holian, NRR 4

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