Re: Estimate DAC [Resuspension factor]

[rkathren@tricity.wsu.edu (Ron L. Kathren)]

Duane --

The literature is replete with information regarding resuspension factors,
which range over 12 or more orders of magnitude depending on conditions.
Allen Brodsky, in a note in Health Physics (39:992, 1980) proposed 10E-6
some years back, a value which I think is sound for general work.  You are
also referred to the excellent review by Healy in Wayne Hanson's
"Transuranic Elements in the Environment", DOE/TIC-22800, pp. 209-235, and
to my own book, "Radioactivity in the Environment", which has a brief
discussion on pp. 239-240.

Ron Kathren


 >On 6/11/97, Paul Ruhter wrote to RADSAFE about resuspension factors
>measurements that had been performed at the TMI-2 facility in the recovery
work for
>that facility. 
>
>I am currently involved, with others at the Nuclear Regulatory Commission
(NRC), in
>work which could benefit greatly from access to data of the type that Paul
described. 
>
>As many of you know, the NRC is in the process of developing a rule on
radiological
>criteria for decommissioning of licensed facilities. In support of the
rule, the NRC is
>developing screening-level dose assessment models, which will be used to show
>compliance with the dose criteria of the decommissioning rule. A few
scenarios are
>considered in these models, but the resuspension data may have applicability to
>dose estimates for contaminated buildings and surfaces. 
>
>For contamination remaining on surfaces, the model uses the resuspension factor
>approach for estimating air concentrations from surface concentrations (the
>resuspension factor is concentration in air [Bq/m^3 or similar] per surface
>concentration [Bq/m^2 or similar], so the units are per meter, or similar).
In searching
>for parameter values to use for INDOOR resuspension factors, the NRC and its
>contractor have found very few published studies with measured data. Most
studies
>located have involved OUTDOOR resuspension, generally from soil, which is not
>really applicable to indoor surfaces. With very few studies to go on, the
development
>of default valus of the indoor resuspension factor is quite difficult, and
there is
>considerable uncertainty involved. Thus, any additional data on
resuspension factors
>in indoor environments would be quite useful to the work we are doing. 
>
>If Paul or any other RADSAFER has access to data on resuspension factors,
>including in the form of unpublished or internal reports, that you would be
willing to
>share, we would appreciate help in obtaining this kind of data. Though I am
not the
>project leader on this work, I am involved, and you should feel free to
contact me
>about this.
>
>Thanks for any help.
>
>Duane W. Schmidt
>U.S. Nuclear Regulatory Commission
>e-mail: dws2@nrc.gov
>
>