ML20138R049

Forwards Addl Info Re SER Opem Item 7A Concerning Unrated Hatch Covers & Oversized Fire Dampers Installed at Facility. Safe Shutdown Analysis Allowed Combination of Fire Areas & Installation of Unrated Hatches & Oversized Fire Dampers

ML20138R049
Person / Time
Site:	Vogtle
Issue date:	11/11/1985
From:	Bailey J GEORGIA POWER CO.
To:	Adensam E Office of Nuclear Reactor Regulation
References
GN-737, NUDOCS 8511180400
Download: ML20138R049 (6)

Text

-

n O

Georgia Power Company Post Offce Box 4545 Atlanta, Georgia 30302 Teve 404 522-6om Vogtl0 Project Southern Company Servces, Inc Post Offce Box 2625 Birmengham, Alabama 35202 Telephone 205 870-6011 November 11, 1985 Director of Nuclear Reactor Regulation File: X6BB06 Attention: his. Elinor G. Adensam, Chief Log: GN-737 Licensing Branch #4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555 REF: NOVAK TO FOSTER DATED JULY 29, 1985 NRC DOCKET NU)tBERS 50-424 AND 50-425 CONSTRUCTION PERhtIT NU5tBERS CPPR-108 AND CPPR-109 V0GFLE ELECTRIC GENERATING PLANT - UNITS 1 AND 2 SER OPEN ITEh! 7A: FIRE DOORS AND FIRE DAbfPERS

Dear ifr. Denton:

Enclosed for your staff's review is additional information related to the untated hatch covers and oversized fire dampers installed at Plant Vogtle.

The safe shutdown analysis has allowed combination of fire areas and therefore the number of unrated hatches and oversized fire dampers installed in fire area boundaries. The enclosure provides additional justification for the VEGP request for deviation from the CbfEB 9.5-1 requirement to install 3-hour fire-rated fire doors and fire dampers in fire area boundaries.

If your staff regtires any additional information, please do not hesitate to contact me.

Sincerely, e .

J. A. Bailey Project Licensing blanager JAB /rlk/caa Enclosure xc: D. O. Foster G. Bockhold, Jr.

R. A. Thomas T. Johnson (w/o enclosure)

J. E. Joiner, Esgiire D. C. Teper (w/o enclosure)

B. W. Churchill, Esqlire L. Fowler bl. A. Fliller (2) W. C. Ramsey B. Jones (w/o enclosure) Vogtle Project File g L. T. Gucwa I

0511100400 051111 PDH ADOCK 05000424 E PDR

~

Attachment 1 Open Item: 7A Fire Doors and Fire Dampers SER Section: 9.5.1.4 Building Design VEGP Unrated Hatch Covers in Fire Area Boundaries Nine (9) of the original ten (10) unrated hatch covers are no longer located in fire area boundary barriers. As such, there is now only one (1) unrated hatch cover installed in a 3-hour fire area boundary barrier. This hatch cover is located at level A of the auxiliary building wing area and separates the train B component cooling water pump room (level A) from the level B corridor area just east of the auxiliary cooling water and safety injection pump rooms. The level B corridor contains Train A safe shutdown raceway.

The hatch opening is used to facilitate equipment maintenance by allowing transporting of large components to and from the plant shop areas. Permanent closure of the opening cannot be allowed from a maintenance standpoint and replacement or modification of the opening so as to obtain a rated closure is not warranted based on the low level of combustibles and the distance separating redundant safe shutdown trains.

The hatch opening is 7' x 12' and while the 1/4-inch thick A36 steel checkered plate hatch cover is not rated or designed as a fire barrier, it does represent a physical barrier and an impediment to fire propagation from one level of the auxiliary building to the other. The rest of the floor area separating the train B equipment area at level A from level B is rated as a three hour fire barrier.

Train A safe shutdown components (includes electrical raceway) are located at least 30 horizontal feet from the underside (level B) of the hatch opening.

Train B safe shutdown components (includes electrical raceway) are located at least 5 horizontal feet from the hatch opening (16' at level A,12' at level 1 and 5' at level 2). The aggregate separation distance between redundant cafe shutdown trains is at least 35 horizontal feet.

There are no combustible materials directly below or above the hatch as these areas are maintained free of obstruction to facilitate equipment moving.

There are no intervening combustibles between the hatch opening and the train 8 safe shutdown components located above the unrated hatch. The only combustible which represents an intervening combustible of significance below the hatch opening is a single cable tray which is at least 15 horizontal feet from the underside of the hatch opening at level B.

l l

l i

e The results of the fire hazards analysis as tabulated below, in addition to i the above, is used to justify this deviation. I Unrated hatch cover, Auxiliary Building Level A, Wing Area Size, ft. 7 x 12 Fire Area Separation 1-AB-LD-G & 1-AB-LA-B Fire Zone Separation 26A & 37 Fire Hazards Fire Zone 26A Fire Zone 37 Fire Load, Ib. 1,144 1,946 (cable insulation)

Combustible Loading, Btu /ft2 6,278 8,469 Fire Severity, min. 4.7 6.4 ,

VEGP Oversize Fire Dampers in Fire Area Boundaries Seven of the original 17 oversize fire dampers are not located in fire area boundary walls. As such, there are now only ten (10) fire damper assemblies (5 each in units 1 and 2) installed (6 vertically and 4 horizontally) in 3-hour fire area boundary barriers which should comply with the guidelines of BTP CMEB 9.5-1. These fire dampers do not bear a UL label of approval as ,

their. size exceeds the manufacturer's UL test limitations.  !

The manufacturer's "as-tested" configuration limits the size of a single fire  !

damper in multiple damper assemblies to 36" x 36". VEGP oversize fire dampers comply with the single damper in multiple damper assembly size limitations.

However, the VEGP oversize fire dampers do not com -

assembly size requirements which is limited to 36" ply when x 72" with the overallindamper installed a horizontal configuration and to 72" x 72" when installed in a vertical configuration. (Note that a 2" wide mullion is provided between single fire dampers in multiple damper assemblies.)

VEGP fire area boundaries have been established in accordance with the i

. guidance of BTP CMEB 9.5-1, Section B.3 " Establishment and Use of Fire Areas"  !

in that separation of redundant safety divisions, separation of safety-related I l systems from fire hazards in nonsafety-related areas and isolation to limit i

! the spread of fires between components that are major fire hazards within a safety division have been considered as well as separation of redundant safe

! shutdown trains.

In spite of the fact that the oversize fire damper assemblies are without a UL l label of approval, the manufacturer has certified that the fire dampers have i been fabricated of the same material, with the same method, and to the same j design and UL procedures as their standard UL approved 3-hour multiple fire "

damper assembly. These oversize fire damper assemblies have been evaluated

[

and found to be acceptable by Bechtel's registered fire protection engineer ,

whose evaluation is attached.

i l

I

• l ,

7

The results of the fire hazards analysis as tabulated below, in addition to the above is used to justify this deviation.

Results of Unit 1 Analysis A. Unrated Fire Damper A-1551-S7-612 Auxiliary Bldg.

Size, in. 94 x 48 Installation Configuration Vertical Number / Size of Single Dampers 6/30 x 23 Fire Area Separation 1-AB-L2-A & 1-AB-L1-B Fire Zone Separation 53 & 149 Fire Hazards Fire Zone 53 Fire Zone 149 Fire Load, lb. 1,567 578 Cable Insulation 21,000 0 Combustible Loading, Btu /f t2 42,545 12,149 Fire Severity, min. 31 . 9 9.1 B. Unrated Fire Damper A-1553-S7-603 Size, in. 48 x 96 Installation Configuration Vertical Number / Size of Single Dampers 2/32 x 23 4/30 x 23 Fire Area Separation 1-AB-L2-A & 1-AB-L2-B Fire Zone Separation 53 8 172 Fire Hazards Fire Zone 53 Fire Zone 172 Fire Load, 1b.

Cable Insulation 1,567 21 3 Charcoal 21,000 5,000 Combustible Loading, Btu /ft2 42,545 46,326 Fire Severity, min. 31 . 9 34.7 C. Unrated Fire Damper A-1553-S7-602 Size, in. 48 x 96 Installation Configuration Vertical Number / Size of Single dampers 2/32 x23 4/30 x 23 Fire Area Separation 1-AB-L2-8 & 1-EB-A I Fire Zone Separation 172 & 141

F 4

Fire Hazards Fire Zone 172 Fire Zone 141 Fire Load, Ib.

, Cable Insulation 213 32 5,000 3,553 Charcoal Combustible Loading, Btu /ft2 46,326 10,143 Fire Severity, min. 34.7 7.6 D. Unrated Fire Damper 1-1551-S7-626 Size, in. 64 x 54 Installation Configuration Horizontal Number / Size of Single Dampers 4/31 x 26 Fire Area Separation 1-AB-L1-B & 1-AB-LD-B Fire Zone Separation 149 & 46 Fire Hazards Fire Zone 149 Fire Zone 46 Fire Load, Ib.

Cable Insulation 578 2,577 Charcoal 0 0 Combustible Loading, Btu /ft2 12,149 4,188 Fire Severity, min. 9.1 3.1 E. Unrated Fire Damper A-1551 -S7-523 Size, in. 52 x 44 Installation Configuration Horizontal Number / Size of Single Dampers 4/25 x 21 Fire Area Separation 1-AB-LD-B & 1-AB-LD-A Fire Zone Separation 46 & 11 Fire Hazards Fire Zone 46 Fire Zone 11 Fire Load, Ib.

Cable Insulation 2,577 7,545 Charcoal 0 0 Combustible Loading, Btu /ft2 4,188 32,445 Fire Severity, min. 3.1 24.3

', t *, . * ,

l'

I have evaluated the 'following oversize

• fire dampers installed at Plant Vogtle:

Tag No. Size .

1. A-1551-57-612 94x48 Vertical '

2. A-1553-57-603 48x96 Vertical

3. A-1553-S7-602 48x96 Vertical l 4. 1-1551-S7-626 64x54 Horizontal

! 5. A-1551-57-523 52x44 Horizontal l 6. 2-1551-S7-626 64x54 Horizontal

7. A-1551-S7-524 52x44 Horizontal i 8. A-1553-S 7-607 48x86 Vertical

9. A-1553-S7-608 48x86 Vertical

, 10. A-1551-S7-613 80x48 Vertical l

l Based upon the review of Air Balance, Incorporated certification of materials l and construction letter of February 24, 1982; UL File R4708-Project 80NK10529 ,

December 1,1980, " Report on Vertically Mounted Fire Deepers of the Curtain '

Type for TWree Hour Classification"; UL File R4708-8-Assignment 690R3968 July 9,1969, " Report on Horizontally Mounted Fire Dampers of the Curtain and i

Round Single Blade Types for 1-1/2 Hour Classification"; my discussions with (

l

= Dennis Kubicki, NRC; the VECP blue prints and specifications; as well as a '

l review of NFPA 90A, and UL Standard 555; and various conversations with the UL

damper committee, it is my opinion that the above fire dampers meet, to an  ;

l engineering certainty, the standards of UL 555 and NFPA 90A and will function t j in the necessary manner as three hour fire barriers.

[ d- k l L. C. Barbe

• l Registered Fire Protection Engineer, California #435 i

l I

• Fire damper size limited to 72x36 for horizontal applications and 72x72 for vertical applications by UL test.

O l

i