Free-Fall Spill an d Impaction Stress

DOE-HDBK-3010-94

5.0 Surface Contamination; Summary

Shock Effects. Based on experimentally measured releases of accumulated

particles from HEPA filters experiencing localized failure from a momentary

high pressure pulse.

Bounding

ARF 2E-6/RF 1.0

Blast Effects. Based on maximum measured release of accumulated particles

by passage of high velocity air through filters to filter break pressure.

Bounding

ARF 1E-2/RF 1.0

Venting of Pressurized Gases Through Filters.

Releases bounded by

ARF and RF for blast effects in section 5.4.2.

Bounding

ARF 1E-2/RF 1.0

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

No applicable experimental data for airborne release of particles during free-fall of HEPA

filters were uncovered. No significant release is postulated during free-fall. Releases on

impact are bounded by conservative extrapolation of maximum releases measured for

contained (in packages) and uncontained HEPA filters.

Enclosed (e.g packages, filter or plena housing) HEPA with accumulated

particles upon impact with hard unyielding surface

Bounding

ARF 5E-4/RF 1.0

Unenclosed HEPA filter media with accumulated particles upon impact with

hard, unyielding surfaces

Bounding

ARF 1E-2/RF 1.0

A erod yn am ic E n train m en t an d R esus pen sion

Since the filters are designed and manufactured to collect and retain particles in flowing air,

no significant release of accumulated particles is postulated by passage of air across face of

filter. Even if the filter medium is exposed, no significant release of accumulated particles

by nominal air velocities is postulated.

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