Free-Fall Spill and Impaction Stress

DOE-HDBK-3010-94

5.0 Surface Contamination; Solid, Noncombustible Surfaces

powders would certainly bound material in this configuration. In either case, the ARF and

RF values are only applied to the loose surface contamination, not the base solid quantities.

5.3.3

F ree-F all S p ill an d I mp action S tres s

No applicable measured data were uncovered. No significant impacts are anticipated for

material that will undergo plastic deformation (e.g., metal, plastics, wood) during free-fall or

upon impact with a hard, unyielding surface. Any suspension of surface contamination is

considered bounded by the bounding values assessed for suspension by shock-vibration. For

materials that undergo brittle fracture (e.g., aggregate, glass), no suspension is anticipated

during free-fall but suspension can occur at impact.

5.3.3.1

F ree-F all S p ill

No significant suspension is anticipated; no data were available. The value assessed for

crush-impact will bound the phenomena.

5.3.3.2

I mp act

5.3.3.2.1 S olid s T h at U n d ergo B rittle F ractu re. If the solid can brittle fracture

(e.g., aggregate, glass) due to crush-impact forces, the activity present on the surface may be

carried by the fragments. The fragmentation of solids into particles in the respirable size

range was discussed in section 4.3.3. The fraction is calculated by:

ARF x RF = (A)(P)(g)(h)

(5-1, 4-1)

where:

ARF x RF

(Airborne Release Fraction)(Release Fraction)

empirical correlation, 2E-11 cm3 per g-cm2/s2

specimen density, g/cm3

gravitational acceleration, 980 cm/s2 at sea level

fall height, cm.

The amount of surface contamination associated with the fraction of base material driven

airborne is assumed to be released.

5.3.3.2.2 S olid s T h at D o N ot B rittle F ractu re. Solids that experience

predominantly plastic deformation (e.g., metal, plastics) as opposed to brittle fracture,

respond to vibration and shock of the substrate by flexing. Materials adhering to the surface

are ejected by the movement depending on how the contaminant is attached to the surface.

The only experimental data that may have any relevance are those for aerodynamic

entrainment from surfaces and the dislodgement mechanisms are different. The bounding

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