Fires cont'd - h3010v10320

DOE-HDBK-3010-94

7.0 Application Examples; Solid Waste Example

showed bulk waste landing on the ground, where it proceeded to burn. There was no

fragmentation of the drum or instantaneous combustion of significant quantities of

waste.

Sealed 55-gal metal drums containing a mixture of combustible materials did not lose

their lids when placed in a wooden structure burned to the ground with combustibles

purposefully stacked around the drums to produce a high fuel loading and associated

heat flux (Greenhalgh, Demiter, and Olson, May 1994). These drums exhibited a

more typical phenomena of lid seal failures producing torch flames from pyrolysis

gases generated in the drums. After the fire consumed the entire building,

examination of the drums revealed the majority of the contents to be uncombusted.

If a waste drum experiences seam or seal edge failure with evolution of flame jets,

the bounding ARF and RF for packaged waste are very conservative because much of

the material inside the drums may not actually burn. If a drum lid blows off at a

sufficient pressure to eject waste from the drum, that portion of the waste that ejects

is considered loosely strewn and assigned the bounding ARF and RF assessed for

uncontained combustible waste. This may be conservative as well because some

waste will land in clumps that may more accurately be characterized as packaged

rather than loosely strewn. For a fire in the drum packaging room in the plutonium

recovery facility, the combustible loading is not of a nature to support extreme heat

generation rates over a short period of time. It consists of bulk-combustible solids,

not highly volatile hydrocarbon fluids such as alcohol or machinery fuels in large

quantities around the drums. Therefore, it would be appropriate to use the bounding

release estimates for packaged waste. For a single maximally loaded drum in a fire,

the initial respirable source term is:

200 g * 1.0 * 5E-4 * 1.0 = 0.1 g

The drum packaging room can store 10 drums in a floor array, so the maximum

source term for a large room fire in this location is 1 g if all of the drums contained

200 g, or 0.15 g if all of the pails contain the historical average loading of 30 g.

Assuming 20 pails were stored in the drum packaging room adds an additional 2E-2

to 1 g to the room fire total. Therefore, for a large fire involving both the pail

storage rooms and the drum packaging room, the total bounding initial respirable

release is between 0.25 g and 5.3 g for the range of average to maximum loading

conditions. The credibility of such a large fire, and thus the utility of the release

estimate, however, can legitimately be questioned. Further, even if the large fire is

deemed credible, the damage ratio can significantly modify release estimates as well.

For example, suppose facility-specific data indicated that 30% of the waste is

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