Applcability of Data cont'd

DOE-HDBK-3010-94

1.0 Introduction

The estimates of ARFs and RFs applicable to various accident-generated mechanisms for the

suspension of radioactive materials are based upon experimental data for specific types and

levels of stresses/force. Care must be used in applying the ARFs/ARRs to ensure that the

values chosen truly reflect the type and level of stress/force postulated for the event. For

instance, the suspension of powder from a surface (commonly termed resuspension) is not

applicable to situations where the powder is dropped into flowing gas in a dispersed fashion.

Before the ARFs and RFs presented can be properly applied, the conditions imposed and the

response of critical items must be evaluated. The calculational methods to perform the

engineering analysis are not part of the scope of this document. Many standard methods are

applicable (e.g., the rupture pressure of tanks and piping based upon the material of

construction, the thickness, the temperature and pressure). In other cases (e.g., the blast

energy from the deflagration of flammable gas and oxidant mixtures in the free volume above

the materials), however, standard engineering calculational methods are not available and

interpretation of information and data (e.g., the fraction of the heat of combustion of

reactants that translates into the shock wave) is required.

Once the forces and conditions imposed upon the material for dispersion/fragmentation and

suspension are identified, the applicable ARF and RF can be selected. In most cases, precise

correspondence between the event conditions and experimental conditions during the

measurement of the ARFs and RFs is not found. For conservative analysis, the data are

applicable if the measurement conditions exceed those calculated for the event (e.g., if the

fall distances for spilled powders or liquids with characteristics like the materials used in the

experiments are equal to or less than the experimental distance of 3 m). In most cases,

extrapolation beyond the experimental data is valid for a limited range beyond the maximum

(a factor of 2 to 5 dependent on the slope of the experimental data and the range of

conditions covered in the experimental study) imposed in the experimental study. Models are

available for the calculation of ARFs and RFs for some phenomena (e.g., free-fall spill of

powders and liquids - Ballinger et. al., 1988; PULF formula for fragmentation by brittle

fracture - Sandia, 1987). Care should be used in any extrapolation, however, to avoid

producing obviously inappropriate answers. This caution is particularly apt if calculations

are being used to influence facility or process design.

A final emphasis is necessary regarding application of this data. As developed for the NRC

and DOE, it has never been intended to be used as absolute proof of anything. Special

attention has been given to understanding suspension phenomena, ranges of relevant

parameters covered in experimental studies, artifacts or limitations of the data that may have

been induced by experimental conditions, and possible effects of relevant parameters that

may not have been controlled or monitored. As noted, this has resulted in development of

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