ML071500212
| ML071500212 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 05/25/2007 |
| From: | - No Known Affiliation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2007-0170 | |
| Download: ML071500212 (7) | |
Text
Fire Modeling At the request of the Region III inspectors, an Office of Nuclear Reactor Regulation (NRR) fire protection engineer performed an analysis of the radiation protection office area to evaluate the potentially hazardous conditions (increased temperature and smoke layer level) that could be caused by a fire and assess the associated damage potential in the fire area.
The staff concluded that hot gas layer temperature in the radiation protection office could reach in excess of 1,006 OF (540 °C) in 9 minutes. The staff's analysis was based on computer fire modeling of the radiation protection office using CFAST (Consolidated Model of Fire Growth and Smoke Transport). CFAST was developed by the Building and Fire Research Laboratory (BFRL) at the National Institute of Standards and Technology (NIST) for fire modeling steady and unsteady state burning rates in multiple compartment configurations (multiple room capability, up to 15 rooms can be modeled) (Jones et al., 2000).
The primary combustibles in the radiation protection office are open bookshelves with paper materials, offices chairs, tables, computers, open plastic recycle bin, and plastic trash can.
Actual fire growth curves from testing have shown that the many common combustibles (e.g.,
cotton, polyester, mail bags, pallets stack) tend to be greater than the t2 medium fire growth (Nelson, 1987). The t2 relationship has proven to be useful and has been adopted into the National Fire Protection Association NFPA 72 to categorize fires for detector spacing requirements and into NFPA 92B for design of smoke control system. For the purpose of this analysis a t 2 medium fire growth rate for these fires was assumed for fire modeling.
The main ignition sources in radiation protection office include coffee makers, toaster, pizza oven, freezer, microwaves, and printer. The electrical failure of one of the ignition source is postulated in this analysis to ignite the combustibles in the radiation protection office.
Based on this information, the inspectors concluded that a fire in the radiation protection office area could adversely affect the post-fire safe-shutdown cable trays in the cable spreading area above due to heat being conducted and radiated through the metal decking.
References Jones, W. W., Forney, G. P., Peacock, R. D., and Reneke, P. A., "A Technical Reference for CFAST: An Engineering Tool for Estimating Fire and Smoke Transport," NIST TN 1431, U.S.
Department of Commerce, National Institute of Standards and Technology (NIST), Building and Fire Research Laboratory (BFRL), Gaithersburg, Maryland, January 2000.
Nelson, H.E., "An Engineering Analysis of the Early Stages of Fire Development: The Fire at the Dupont Plaza Hotel and Casino on December 31, 1986," NBSIR 87-3560, U.S. Department of Commerce, National Bureau of Standards (NBS), Gaithersburg, Maryland, May 1987.
NFPA 72, "National Fire Alarm Code," 1999 Edition, National Fire Protection Association, Quincy, Massachusetts.
NFPA 92B, "Guide for Smoke Management Systems in Malls, Atria, and Large Areas," 2000 Edition. National Fire Protection Association, Quincy, Massachusetts.
2500 2250 >
Input Heat Release Rate Output Heat Release Rate from CFAST Based on Available SMedium Fire Growth Rate Oxygen in Rdaiation Protection Office 2000 1750
'- 1500 (Z
cc (o 1250 Cz a)
__¢ CC r 1000 Co I
750 500 250 -
0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Time (sec)
Input and Ouput Heat Release Rate for CFAST Fire Model, Fire in Radiation Protecion Office
0 0 0 0 60 42.192 60 42.2 120 168.768 120 169 150 263.7 180 387 200 468.8 240 769 440 2268.992 300 1218 360 1667 420 2115 480 2262 540 2262 600 2262 660 2262 720 2262 780 2262 840 2261 900 2261 960 2261 1020 2261 1080 2261 1140 2261 1200 2261 1260 2261 1320 2261 1380 2261 1440 2261 1500 2261 1560 2261 1620 2261 1680 2261 1740 2261 1800 2261
600 550 1032 500 932 450 TLD Issue Room 832 0 400 0)
(D
.(D 350 Q- 632 5 E E
- 300 a)
HP Office H (D 532 CU -j
-J 250 U) 432(.
- 0 0 200 332 150 232 100 132 50 0 1-32 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 1800 Time (sec)
Temperature Rise in Radiation Protection Office, TLD Issue Room, and HP Office, Fire in Radiation Protection Office
0 25 25 25 77 60 50 34.4 25 77 120 109 67.2 37 98.6 180 170 110 50.3 122.54 240 279 192 83.7 182.66 300 361 269 135 275 360 424 321 183 361.4 420 489 368 226 438.8 480 534 399 254 489.2 540 541 406 260 500 600 543 408 263 505.4 660 544 410 264 507.2 720 545 412 266 510.8 780 546 413 267 512.6 840 547 415 268 514.4 900 548 416 269 516.2 960 549 417 270 518 1020 550 419 271 519.8 1080 551 420 272 521.6 1140 552 421 273 523.4 1200 553 422 274 525.2 1260 554 423 275 527 1320 554 424 275 527 1380 555 425 276 528.8 1440 556 426 277 530.6 1500 557 427 278 532.4 1560 557 428 278 532.4 1620 558 429 279 534.2 1680 559 429 280 536 1740 559 430 280 536 1800 560 431 281 537.8
NRR Primarily CFAST Fire Modeling Results I I Kewaunee Nuclear Plant
T 4 + 4 Fire
^
in Radition Protection Office i -i-- 4 I I t2 Medium Fire Growth Rate I__________ I1- I I I I__________
Door at Location 56 is Open T t 1-4 4 + 4 Sl System English System Rad Pro Office TLD Issue RM HP Office Rad Pro Office TLD Issue RM HP Office Time (sec) Hot Gas Layer Hot Gas Layer Hot Gas Layer Time (sec) Hot Gas Layer Hot Gas Layer Hot Gas Layer (sec) Temp (°C) Temp (°C) Temp ('C) (min) Temp (OF) Temp (OF) Temp ('F) 0 25 25 25 0 77 77 77 60 50 34.6 25 1 122 94.28 77 120 109 67.7 37.9 2 228.2 153.86 100.22 180 170 109 49.8 3 338 228.2 121.64 240 279 192 83.4 4 534.2 377.6 182.12 300 361 269 135 5 681.8 516.2 275 360 424 321 183 6 795.2 609.8 361.4 420 489 368 226 7 912.2 694.4 438.8 480 534 399 254 8 993.2 750.2 489.2 540 541 406 260 9 1005.8 762.8 500 600 543 408 263 10 1009.4 766.4 505.4 660 544 410 264 11 1011.2 770 507.2 720 545 412 266 12 1013 773.6 510.8 780 546 413 267 13 1014.8 775.4 512.6 840 547 415 268 14 1016.6 779 514.4 900 548 416 269 15 1018.4 780.8 516.2 960 549 417 270 16 1020.2 782.6 518 1020 550 419 271 17 1022 786.2 519.8 1080 551 420 272 18 1023.8 788 521.6 1140 552 421 273 19 1025.6 789.8 523.4 1200 553 422 274 20 1027.4 791.6 525.2 1260 554 423 275 21 1029.2 793.4 527 1320 554 424 275 22 1029.2 795.2 527 1380 555 425 276 23 1031 797 528.8 1440 556 426 277 24 1032.8 798.8 530.6 1500 557 427 278 25 1034.6 800.6 532.4 1560 557 428 278 26 1034.6 802.4 532.4 1620 558 429 279 27 1036.4 804.2 534.2 1680 559 429 280 28 1038.2 804.2 536 1740 559 430 280 29 1038.2 806 536 1800 560 431 281 30 1040 807.8 537.8
VERSN 3 Kewanuee Nuclear Plant-Fire in Rad Protection Office-t2 Medium Fire Growth Rate TIMES 1800 60 60 60 0.0 TAMB 298. 101300. 0-0 EAMB 298. 101300. 0.0 HI/F 0.00 0.00 0.00 WIDTH 5.18 5.18 3.96 DEPTH 8.30 5.25 2.43 HEIGH 2.43 2.43 2.43 HVENT 1 2 1 3.35 2.13 0.0 0.0 0.0 0.0 0.0 0.0 HVENT 1 4 2 0.91 2.13 0.0 0.0 0.0 0.0 0.0 0.0 HVENT 2 3 1 0.91 2.13 0.0 0.0 0.0 0.0 0.0 0.0 HVENT 2 4 2 1.82 2.43 1.52 0.0 0.0 0.0 0.0 0.0 CVENT 1 4 2 0.91 2.13 1.0 1.0 1.0 1.0 1.0 1.0 CEILI CONCRETE CONCRETE CONCRETE WALLS CONCRETE CONCRETE CONCRETE FLOOR CONCRETE CONCRETE CONCRETE CHEMI 16. 10. 10. 20000000. 298. 388. 0.2 LFBO 1 LFBT 2 FPOS 1.0 1.0 0.0 FTIME 60.0 120.0 150.0 200.0 440.0 FHIGH 0.5 0.5 0.5 0.5 0.5 FAREA 0.5 0.5 0.5 0.5 0.5 FQDOT 0.0 42192.0 168768.0 263700.0 468800.0 2268992.0 CJET OFF CO 0.03 0.03 0.03 0.03 0.03 OD 0.08 0.08 0.08 0.08 0.08 HCR 0.13 0.13 0.13 0.13 0.13 STPMAX 1.00 DUMPR KNP3.Hi DEVICE 1 WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U HEAT 0 0 0 0 2 1 U