ML20079G196

Structural Steel Analysis for Limerick Generating Station: Unit 1 Turbine Bldg,El 295-Ft 3 Inches,Pipe Chase Svc Room 523

ML20079G196
Person / Time
Site:	Limerick
Issue date:	01/04/1984
From:	PROFESSIONAL LOSS CONTROL, INC.
To:
Shared Package
ML20079G166	List: ML20079G163 ML20079G181 ML20079G188 ML20079G196 ML20079G202 ML20079G216 ML20079G220 ML20079G223 ML20079G227 ML20079G233
References
NUDOCS 8401190462
Download: ML20079G196 (6)

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(( Professional Loss Control, Inc.

I STRUCTURAL STEEL ANALYSIS for  !

LIMERICK CENERATING STATION Unit 1 Reactor Building El. 295'3" l Pipe Chase Service Room 523 January 4, 1984

@A01190462 840113 PDR ADOCK 05000352 F PDR P. O. Box 446 e Oak Ridge, Tennessee 37830 e (615) 482-3541

m k.

LIMERICK GENERATING STATION

1. AREA DESCRIPTION The area under consideration is the Pipe Chase Service Area, Room 523, on the 295'-3" elevation of the Unit 1 Reactor Building. Bounding walls are of reinforced concrete construction. The average wall thickness is 3.5 ft.

The total surface area for heat transfer is 1742 ft2 (see Attachment A for sketch-and calculation of surface areas).

2.. COMBUSTIBLE LOADI,NG Combustible loading in this area consists of cable insulation in cable trays. The total surface area of the cable trays is 104 ft2 with an average combustible loading of 4.0 lbs/ft2 of cable tray surface area. There are no combustible' liquids in this area.

3. VENTILATIPN PA'AMETERS R

One door located in the west wall and measuring 3' wide by 7' high enters this area.

4. CASES EXAMINED A spreading cable fire was assumed to originate in the area of heaviest cable concentration in order to present the worst case. The fire is assumed to start at a point source and spread horizontally along the cable trays in each direction at a rate of 10 feet per hour. The fire will spread along all of the horizontal cable trays intersecting the point source for a dis-tance of 7 feet in each direction before the original point source dies out after 40 minutes. A maximum surface area of 104 ft2 of cable trays (see Attachment B for a list of trays) will be involved at any one time, which corresponds to a heat output of 1836 kW. This heat output is assumed con-

.stant throughout the fire duration. The actual heat output as the fire spreads out of the area originally involved would be less since the quanti-ty of cabling that would be involved at any one time would be less.

5. RESULTS The case examined assumed one 3' x 7' door open with a spreading cable fire.. This resulted in a fuel controlled fire with a heat output of 1836 1

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kW and a duration of 40 minutes. The gas temperature at this time would be 817*F which is below the critical temperature of the structural steel (see Attachment C for results of analysis).

The location of cable trays relative to structural steel members was examined in the area. No cable trays were positioned so as to present a localized heating exposJre to the structural steel.

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Unit 1 Reactor Building.El. 295'-3" Pipe Chase Service Room 523 Surface Area Calculation

' Walls-

- North wall

~ (16' x 17') 272 ft2 South ~ wall (16' x 17') 272 ft2

-East wall (21' x 17') 357 ft2 West wall- (25' x 17') 425 ft2 1326 ft4-

' Ceiling Area 1 '(16' x 24') 384 ft2 Area.2- 1/2:(4'x'16') 32 ft2 Total Surfa'ce Area for Heat-Transfer 1742 ft2

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ATTACHMENT A

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The following cable trays are present' in the area defined for the source fire and all of the trays are assumed to be burning simultaneously:

Surface Tray No. Width (in.) Length (ft.) Area (ft2) 1ACXA95 24 . 5 10 1ACXA96 22 7- 14 1ACYA95 24' 5 10 1ACYA96 24 7 14 1MIAA01 24 14 28 1MIAB01 24 14 28 104 ft2 Average combustible loading per tray surface area = 4.0 lbs/f t?

Fire' duration for free burning tray fires =

4.0 lb/ft2 4 .1 l b = 40 minutes.

T~t4/ min Heat output with all trays in source fire area (above) burning

. simultaneously:

104 ft2 _ x 190 kW/m2 = 1836 kW 10.76 ft'/m' ATTACHMENT B-

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CASE-NUMBER: 1

' BUILDING: UNIT 1 REACTOR BUILDING .

ELEVATION AND AREA DESCRIPTION: 295.25' EL. PIPE CHASE SERVICE AREA CASE DESCRIPTION: ONE 3'x7- DOOR OPEN SPREADING CABLE FIRE n oo n * * * *

• x * * * *

• x x * * * * * * * * * * * * * * * *

• x * * * * *

• x x x *

• x *

• x * * * * * * * *

• x x x x x x x x x *

• x

• CEILING / WALL CEILING / WALL ~ Ao Ho Aw 0 THICKNESS- MATERIAL (ft) ,

(ft2) (ft) (ft2) (kW) conuww*uxxx**x**x***x********xx*x****x: 4

• x * * * *

• x x *

• x. *

• x x * * * *

• x x x * * * * *

• r

• o 3.5 CONCRETE 21.0 7:0 1742 1036

, FIRE IS FUEL CONTROLLED FIRE DURATION GAS TEMPER ATURE (min) (dea.F) 1 192 2 240 3 277

4. 309 5 336 6' ' 361 7 384 8 406 9 426 10 4 '. 5 11 463 12 401 13 497

~14 513 15 52Y 16 544 17 558

.1 lB 572 19 586 20 599 21 612 22 625 23 637 24 650 25 661 26 673 27 605 28- 696 29 707 30 718 31 728

32. 739 33 749 34 759 35 769 36 779 37' 789 38 799 39 808 40 817 ATTACfNENT C

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