Surface Contamination

DOE-HDBK-3010-94

5.0 SURFACE CONTAMINATION

Release fractions are assessed for combustible and noncombustible materials on which

surface contamination may be found. Combustible materials include solids such as trash,

wood, and wall board. Trash may be made up of paper, rags, cardboard, and plastic

(wrapping sheets, bags, containers, glovebox windows, tools, casings, and ion exchange

resins). Where possible, distinctions are made between loose combustibles and combustibles

in containers (e.g., pail packages, drums). Noncombustible materials are generally large

pieces associated with the facility structure, enclosure, or containers. Such pieces or

equipment may be concrete, metal, glass, etc. This material may include hard, unyielding

surfaces, deformable surfaces, or even brittle surfaces. The contamination ARF and RF

values, with the noted exceptions of burning and explosive shocks fragmenting base surfaces,

are intended to be applied to loose surface contamination only.

An RF of 1.0 is assigned for the majority of these materials. To be technically correct,

however, in all cases the total quantity of airborne respirable material should not exceed the

total mass of respirable material in the original source MAR. Unfortunately, it is very

difficult to characterize the size distribution of deposited radioactive contamination, which

may come from a large number of different sources and is intermingled with non-radioactive

particles that are not of interest. Accordingly, it is not expected that defensible bases exist

for assuming an original source RF in most cases. Given that, it is important not to treat

significant powder accumulations as being a surface contamination phenomena.

5.1

SUM M ARY O F ANALYSIS O F DATA

C on tam in ated , C om b u stib le S olid s

T h erm al S tres s

Packaged Mixed Waste. For contaminated combustible materials

heated/burned in packages with largely non-contaminated exterior surfaces

(e.g., packaged in bags, compact piles, pails, drums), the following values are

assessed to be bounding. These values are based on the maximum

experimentally determined ARF and conservative assumption of RF = 1.0.

Median

ARF 8E-5/RF 1.0

Bounding

ARF 5E-4/RF 1.0

Uncontained Cellulosics or Largely Cellulosic Mixed Waste. For burning of

unpackaged, loosely strewn cellulosic materials, such as paper, cardboard,

rags, and wood shavings, the following values are assessed to be bounding.

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