Chemically Reactive Compounds

DOE-HDBK-3010-94

4.0 Solids; Powders

values here probably represent the material that could be entrained. It would appear that for

nonreactive powders, temperature has little effect on entrainment. Therefore, a value, based

on entrainment at high velocities compared to convective flow, of 6E-3 is assessed to be

bounding for the material.

The size distribution of the airborne material was not measured during these experiments.

The entrainment appears to be entirely due to the airflow with temperature playing a minor

or negligible role. In the other experimental studies, special efforts were required to obtain

initial source powders with RFs in the range of 0.01 to 0.1. Even so, powders at rest are

difficult to deagglomerate (see Figure A.41). The RF for reactive powders discussed below

generated very small RFs (<0.00001). Since entrainment for nonreactive powders depends

solely on airflow and the same airflow was applied in the experiments with reactive powders,

there is no compelling reason for the RFs to be orders-of-magnitude apart. The oxides

formed from these reactive compounds can be very fine under the proper circumstances

although, under the experimental conditions, large amounts of fine oxide were not generated.

Under fuel cycle facility accident conditions, much of the oxides present would be from the

oxidation of reactive compounds and metal that would have characteristics similar to those

generated by heating reactive compounds used in these experiments. On these bases, an RF

value of 0.01 was selected as a reasonable, conservative value consistent with other measured

RFs discussed below.

4.4.1.2

Chemically Reactive Compounds

The measured ARFs during heating of reactive plutonium compounds in flowing air are listed

in Table 4-11. The median and bounding ARFs for the four reactive compounds tested are:

Bounding

Median

partially oxidized Pu oxalate

4.4E-3

8.8E-3

Pu oxalate

1.0E-4

9.5E-3

Pu fluoride

<8.0E-5

7.0E-4

air dried Pu nitrate

1.5E-4

1.5E-3

The ARFs for reactive plutonium compounds appear to fall into 2 groups. The ARFs

measured for the two oxalate forms have maximum values near 1E-2. The value for nitrate

is much lower but the median value for this compound is similar to the value for oxalate.

Due to the uncertainty of the completeness of the oxidation, it is assumed that the nitrates

behave as oxalates and an ARF of 1E-2 is assessed to be bounding for these compounds.

Page 4-57