Text

Structural Steel Analysis:Reactor Bldg,Elevation 253 Ft, General Floor Area,Fire Area 45A
	ML20078R784
Person / Time
Site:	Limerick
Issue date:	11/01/1983
From:	; PROFESSIONAL LOSS CONTROL, INC.
To:	;
Shared Package
ML20078R738	List: ML20078R735; ML20078R744; ML20078R759; ML20078R775; ML20078R784; ML20078R786; ML20078R791;
References
	NUDOCS 8311150293
	Download: ML20078R784 (8)
	v • d • e

, _ --- - -_- - ..._ _ . . . . . _ . . _ . _ . _ . _ _ - _ _ _ -- -_ _ . _ -

i

}(( Professional Loss Control, Inc.

STRUCTURAL STEEL ANALYSIS for LIMERICK ATOMIC GENERATING STATION Unit 1 Reactor Building, El. 253' General Floor Area

.. . Fire Area 45A November 1, 1983 Of[30fgjos --

eBR .

r 7922 West Chester Pike

Upper Darby, Pa. 19082 * (215) 853-1700

r LIMERICK GENERATING STATION

1. AREA DESCRIPTION l The area under consideration is the general floor area on the 253' ele-

.vation of the Unit 1 Reactor Building (Fire Area 4EA). The heaviest combustible loading encountered on this elevation is found in the CRD Hydraulic Equipment Area and Neutron Monitoring System Area. The area of heaviest combustible loading is bounded by column lines 19.4 & 23 and J & Fa (see Attachment A for a sketch of the area under considera-tion). The total surface area for heat transfer is approximately 11,774 ft .2 The bounding walls are constructed of reinforced concrete with an average thickness of 1.5 ft.

2. COMBUSTIBLE LOADING The heaviest concentration of cabling found within this area was along the east wall. The average combustible loading of the cable trays in this area is 4.7 lbs/ft2 of tray surface area. There are no combustible liquids in this area. Enclosed combustibles are not included in the combustible loading.-

3. VENTILATION PARAMETERS The area under consideration is open .to the remainder of this elevation on its south side. This opening is approximately 28.5 ft. wide and 29 ft. high.

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 north and south along the east wall and westward a distance of 8 feet in each direction along the cable trays before the original point source dies out after 47 minutes. A maximum s'urface area of 386 ft2 of cable trays (see Attachment B for a list of trays) will be involved at any one time, which corresponds to a hea't output of 6816 kW. This heat output is assumed constant throughout the fire duration.

The actual heat output as the fire spreads out of the area originally involved would be less since the quantity of cabling involved at any one time would be less.

1

--- - - . - . . _ . , . . . - . . . . - . _ . - . _ . . _ . . . . . ~ - - . . - . . . . . . . - - . . . - . . - -

5. RESULTS The fire duration was taken to be 180 minutes and the fire temperature reached after 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> was 940*F which is below the critical temperature for the structural steel (see Attachment C for results of analysis).

Since the- fire is assumed to occur in the area of heaviest combustible loading, the results are considered to be representative for the entire general floor area on the 253' elevation of the Reactor Building.

The positions of cable trays relative to structural steel members were examined throughout the 253' elevation of the Reactor Building in order to assess the potential for localized heating. Cable tray 1AGY05 is located 12" below the bottom of a girder type G-52 (54WF366).

Attachment D contains the results of calculations performed to deter-mine the response of the girder to localized heating. These calcula-tions are conservative because they assume that the entire length of the girder is subjected to a temperature of 1500*F when in actuality only a small section of the steel would be subjected to localized heat-ing. As can be seen from the results, the girder does not reach its single point failure temperature of 1300*F during the 50 minute expo-sure period (time required for a tray to burn to completion).

t #

2

a l, '\,

'i

,e.l

'~'

i ui d- !

.M '

9 N- ' n , '

, .-' g \ @. 1 ,h!:M

, . I

~'

h l 1 i N l8 I l

\ / I 8

,,\

% W ,.-

r 6 .

/ k{ *$

l. rf .,

' y

'~~ 'N -

?'

L n l 4

Unit 1 Reactor Enclosure 253' El.

Surface Area Calculation Walls North wall above Neutron Mon. (18' x 19') 342 ft2 North wall. Neut. Mon. to Stairway (35'x28.5') 997.5 ft2 North wall stairwell (8'x28.5')-(3'x7') 207 ft2 East wall (67' x 28.5') 1909.5 ft2 Column North & South Faces East Wall (16'x28.5') 456 ft2 Drywell Access Wall (16' x 28.5') 456 ft2 Drywell wall above Neutron Mon. . (22'x19') 418 ft2 Drywell wall from Neut. Mon to Access (49' x 28.5') 1396.5 ft2 Neutron Monitoring Walls (63' x 9.5') - (3' x 7') 577.5 ft2 6969 ft2 I'

ATTACHMENT A .

L :_= === _= _ - _ _ - . - - - - - - - - - - - - -

Ceiling Area 1 (27' x 11') 297 ft2 Area 2 1/2(27' x 41') - 240 ft2 313.5 2 Area 3 (46' x 74') 3404ft{t Area 4 1/2(22' x 6') - 21 ft2 45 ft2 Area 5 -

4' x 61') 244 ft2 Area 6 4' x 4') 16 ft2 Area 7- 4' x 42') 168 ft2

-Area 8 21' x 12') 252 ft2 Area 9 1/2(11' x 12') 66 ft2 4805.5 ft2 Total Surface Area for Heat Transfer = 11,774 ft2 0

ATTACHMENT A

tu.-..-..-...-.-...-. . . - - ~ .. .. - -. - - - - _ - ..- - - - . .

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 (ft21 1DCPA79 24" 2' 4 10CAA74 24" 16' 32 10CVA72 24" 5' 10 10CBA72 24" 10' 20 10CQA21 24" 12' 24 11CCA21 24" 16' 32 10CZA21 24" 9.5' 19 10CPA74 24" 7' 14 1CDPA75,76,78 24" 5' 10 1DCQA76 24" 11' 22 11CLA74 24" 11' 22 10CDA74 24" 11' 22 10lYA74 24" 11' 22 10CZA74 24" 8' 16 11CCA74 24" 8' 16 10CBA74 24" 8' 16 10CDB13 24" 11.5' 23

'~

101YB13 24" 15' 30 10CDB12 24" 8' 16 101YB12 24" 8' 16

, 386 ft2 Average Combustible Loading per Tray Surface Area = 4.7 lb/ft2 Fire Duration for Free Burning Cablg Tray Fire =

4.7 lb/ft 4 01 lb = 47 minutes ft'/ min Heat output with all trays in source fire area (above) burning simultaneously:

386 ft2 _ x 190 kW/m2 = 6816 kW 10.76 ft4/m' ATTACHMENT B

[djd.yy'7-' , ' ' '*'; '

f _ -

', CASE ANUMBEft 1,, .1 BUILDING: ' REACTOR ENCLOSURE UNIT 1 ELEVATION AND AREA DESCRIPTION: 253'EL. NORTHEAST CORNER TASE : DESCRIPTION : .

SPREADING CABLE FIRE

'. .c x x

w x * *

x x x x

x x x x x

x x x x x x

x x x x x x x * * *

x x x *-x x xa: y x x x x x x *

x x x x x x x x x x x x x x

,v ,

CEILING / WALL CEILING / WALL Ao Ho Aw Q THICKNESS MATERIAL (ft) (ft2) (ft) (ft2) (kW) 0"c a u x x x

x x x x x x x x

x x x x

x x x x x x x x x x

x x x x x x x x x x x

x x r t-x x x x x x x-x x r x x -x x x x x

x x ,

1.5 CONCRETE U26 27 11774 6816 b

FIRE IS FUEL CONTROLLED FIRE DURATION GAS TEff ER ATURE (Min) (deg.F) 10 277 20 362 30 427 40 402 50 530 60 573 70 614

~

80 6b1 90 606 o

e 100 719 110 751 120 701 130 010 140 830 150 065 160 891 170 916 100 940 s

. e

W .

s ,

I '::t ATTACHMENT C

.y. i

= . s e

.yyk &

>> 1

.. 'i .

g., *

,, Y.

'e . .

5' Q . :

.; ; ; , J ' .';: ' . tr -

. m :.,:- w- . ,a

y ..- ,

e,-- , s .; . w .t.z . . -

.r n s , t*

s

. CASE. NUMBER 1 .

, 'BUILDINGV UNIT 1 REACTOR BUILDINC ELEVATION AND AREA DESCRIPTION: 253' GENER AL FLOOR AREA CASE. DESCRIPTION: LOCALIZED HEATING OF MEMBER TYPE G-52 (54WF366)

. q-

' ~

=4 *e ,

. [,,4:'.j " EFFECTS OF LOCAL HEATING ON STRUCTURAL STEEL

, ,a ' ., y (g v *.

' FIRE TEMPERATURE (deg. F): 1500 WEIGHT OF STEEL MEMBER (lbs./ft): 366 SURFACE OF STEEL MEMBER HEATED (sq .f t ./f t ): 13.30 TIME STEEL TEMISERATURE

. (Min) (dog.F) 5.00 274 10.00 450 15.00 600 20.00 729 25.00 040 30.00 935 35.00 1016 1005 40.00 45.00 1145 50.00 1196 4

0 e

k e

e a 9 4

e b

4 4 g y'

sq** ATTACHMENT D h ,

O $ t

-wg ,- --_

ML20078R784

Text

Navigation menu

Search