Release Estimation - h3010v10311

DOE-HDBK-3010-94

7.0 Application Examples; Reduction Line Example

prior to initiating hydraulic seal of the reduction can. Only one incident occurred after

standardization of gasket specifications and was due to installation of a previously used

gasket. No incidents have occurred since the use of pyrotechnic initiators to lower ultimate

reduction pressure began in 1977.

7.3.8.2

Release Estimation

The potential energetic phenomena considered in this example are pyrotechnic initiation

outside the reduction furnace, failure of the pressure seal on the reduction can, and hydrogen

explosion in proximity to plutonium powder.

A. Pyrotechnic Initiation. If the reduction reaction that generates molten products

has initiated, it is not physically possible for an unfired pyrotechnic charge to remain

in the crucible. Therefore, the pyrotechnic charge itself can affect only plutonium

fluoride powder, although the heat generated by the onset of general reduction could

affect plutonium metal as well. The exact mechanism for initiating a charge is

immaterial and is considered to be one of the two previously discussed. If the charge

fires as it normally should, the main effect will be heat. The reduction reaction itself

may be initiated, in which case flames would be visible from the combustion of

calcium and some plutonium if the glovebox were not inerted. Such an event has

been observed in the history of the DOE complex. In one case, there was only a

brief flash of flame, while in another the combustion had to be extinguished by

pouring magnesium oxide sand over the crucible.

The amount of plutonium present as plutonium fluoride is between 1000 and 2000 g.

If the release is considered a product of heating plutonium fluoride powders only, the

ARF and RF from section 4.4.1 are, as previously discussed, a maximum of 1E-3 and

0.001. The initial respirable source term is:

(1000 to 2000 g) * 1.0 * 1E-3 * 0.001 = 1E-3 to 2E-3 g

If plutonium metal were assumed to rapidly form in a molten state, the molten metal

could begin to burn. That would not happen in this example process due to the use of

nitrogen inerting, but it will be evaluated for the sake of example. For burning

plutonium metal, the ARF and RF are, as previously discussed, 5E-4 and 0.5

(subsection 4.2.1.1.3). The maximum initial respirable source term (i.e, the highly

unlikely event that all material burns) is:

(1000 to 2000 g) * 1.0 * 5E-4 * 0.5 = 0.25 to 0.5 g

Page 7-55