Large Room Fire

DOE-HDBK-3010-94

7.0 Application Examples; Liquid Storage and Ion Exchange Examples

11,650 g * 1.0 * 2E-4 * 0.5 = 1.2 g

If all process tanks are full at their flowsheet parameters, the MAR is 42 kg. The

free-fall spill of all this material produces an initial airborne source term of:

(7920 g * 1.0 * 2E-5 * 1.0) + (34,960 g * 1.0 * 2E-4 * 0.5) = 3.7 g

A pipe or tank failure that resulted in the release of a pressurized spray due to pump

pressure, would produce the same release as free-fall spill for the lower density

solutions (i.e. < 1.2 g/cm3), and a greater release for the high-density solutions.

This scenario would be similar to the spray leak examined for the metal dissolver in

subsection 7.3.4.2. The physical phenomena is depressurization of liquid via a failure

under the liquid surface level, for which the ARF and RF are 1E-4 and 1.0

(subsection 3.2.2.3.1). If the spray failure occurs for one of the high density ion

exchange feed tanks, the initial airborne source term is:

1320 g * 1.0 * 1E-4 * 1.0 = 0.1 g.

The free-fall spill release for the high-density solution is only 0.03 g.

B. Large Room Fire. There is no obvious mechanism for postulating a large room

fire in the maintenance side of the wet processing line, but one is postulated from an

undefined source. Unlike the previous case where an undefined large fire was

postulated (Feed Preparation example, section 7.3.1), it will cause a significant

increase in source term for the process. The principle mechanisms for release are

boiling of liquid and release of superheated liquid.

Before estimating releases, it is appropriate to consider the type of fire that would

significantly affect the stored liquid. The precipitator feed tanks (13 and 14) have

both the largest plutonium (11,650 g) and smallest liquid inventories (130 l). The

heat required to boil and vaporize this solution is estimated assuming the

thermodynamic properties of water, the density of the nitric acid solution, and an

initial temperature of 30 oC. The sensible heat needed to raise the temperature to

boiling is:

130 l * 1000 cm3/l * 1.3 g/cm3 * 1 cal/g oC * (70 oC) = 1.2E+7 calories

The latent heat needed to vaporize the solution is:

130 l * 1000 cm3/l * 1.3 g/cm3 * 539 cal/g = 9.1E+7 calories

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