Uncontained, Cellulosic Waste or Largely Cellulosic Mixed Waste

DOE-HDBK-3010-94

5.0 Surface Contamination; Contaminated, Combustible Solids

exist around waste under most fire situations, more generic close-proximity plateout is

expected for real situations. Accordingly, for all practical purposes there is no need to

attempt highly uncertain phenomenological modelling to distinguish between the effects.

Based upon the above data, a bounding ARF is assessed to be 5E-4 for packaged waste. For

this purpose, even waste in taped plastic bags or pails is considered packaged. In lieu of any

measured size distribution for the airborne materials, a conservative RF of 1.0 is assessed to

be bounding.

5.2.1.2

U n con tain ed , C ellu losic W aste or L argely C ellu losic M ixed W aste

The ARFs from the burning of contaminated cellulosic materials have been measured in three

sets of experiments by Mishima and Schwendiman (1970) and Halverson, Ballinger, and

Dennis (1987). The relevant experiments for this subsection involved very small specimens

in a stainless steel shallow dish in a forced air upflow of ~ 60 mm/s, and in a shallow

aluminum pan centered in a 0.18-m i.d. quartz tube. An additional set of experiments

relevant to the next subsection involved an upflow of air during combustion. The results of

all these experiments are reproduced in Tables A.47, A.48, A.50, and A.54 in Appendix A,

and the relevant data from the three sets are summarized in Table 5-2. The experimental

apparatus used by Halverson, Ballinger, and Dennis is shown in Figure A.43 in Appendix A.

Caution is necessary when interpreting the data relevant to this subsection. The airflows

reported do not correspond to velocities at the actual pyrolysis gas-fuel interface where the

gasflow effect is relevant. The variability in materials and contamination orientation are at

least as significant. The data is neither sufficient in quantity nor sufficiently varied in

parameter investigation to support characterizing results as a function of variables.

In most cases within the DOE complex, contaminated materials are multiply contained (e.g.,

plastic bags/wrappings inside plastic/metal/wood containers). Finding significant quantities

of uncontained highly contaminated materials uncontained ex-process (storage or handling) is

the rare exception rather than the rule. The experimental configuration from which these

values are obtained was limited by the space available and tended to be very small (with

respect to what is anticipated in facilities). Gram quantities were used rather than kilogram

or multi-kilogram quantities, and these did not provide the depth of burn-residue that may

attenuate airborne release from large piles of material. The radionuclides (such as plutonium

solutions) were freshly applied and emphasized the goal of maximizing release. The

experimental configuration did not allow the contaminant material to attain the degree of

adhesion and packing expected for real stored wastes. Accordingly, the values may be very

conservative for most, if not all, applications.

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