Resuspension rates, radionuclides

Thus, the resuspension rate A is the fraction removed per second by resuspension process. The use of this quantity with a suitable dispersion and deposition model would enable the movement of a radioactive nuclide from place to place to be predicted. Such an approach is necessary for estimating the radionuclide concentration in air due to resuspension downwind of an area heavily affected by the deposition process. Whether kr or A is used, it is clear that the value of the parameter must be expected to vary with many environmental variables. The most important of these environmental variables will be time after deposition, surface structure, nature of the radioactivity, wind speed, surface moisture and rate of mechanical disturbance of the surface. 

During shutdown of a PWR plant and, somewhat less pronounced, also during its startup, a strong increase in the concentrations of corrosion products and the associated radionuclides in the primary coolant is observed, an effect which will be discussed in more detail in Section 4.4.3.3. This process causes a dissemination of the radionuclides over the entire primary circuit and, as a possible consequence, results in increased radiation dose rates in the area surrounding it. For this reason, the origin of these radionuclides is of interest, with their possible source being the resuspension of activated corrosion products previously deposited either inside or... 

Options for remediation include removal of surface soil, fixation to prevent mobilization by processes such as wind resuspension, amendment to reduce radionuclide transfer to plants and animals, covering with imcontaminated soils to reduce external radiation dose rates and to reduce uptake into plants and animals. Other potential courses of action include administrative measures to limit the uses of the land, for example, so that it is not used for human habitation, thereby reducing exposures or to exclude access completely. 

The set of regularly obtained data on radionuclide concentrations in air can be directly used to assess the annual intake and the associated committed dose. If measurement data are unavailable or insufficient, radionuclide concentrations in air can be roughly estimated from soil deposition rates by using a resuspension model. 

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