Colloid Facilitated Transport of Radionuclides at the Field Scale: Model and Parameter Sensitivities
Abstract
The potential effect of naturally occurring inorganic colloids on field-scale transport of radionuclides is investigated using generic sensitivity studies and an example based on the alluvial aquifer near Yucca Mountain, Nevada. The linear, bi-linear, and Langmuir models are used to describe kinetically controlled sorption to mobile and immobile colloids. In the absence of colloid retardation and permanent removal, plutonium transport is greatly enhanced over the situation without colloids. Mass transfer between solution and immobile colloids makes colloid retardation relatively ineffective at reducing facilitated transport except when the retardation factor is large. Irreversible removal of colloids (filtration) is more effective than colloid retardation at reducing facilitated transport. For a fixed filtration rate, the degree of attenuation depends sensitively and non-monotonically on the rate of desorption from colloids. These results emphasize the need for accurate measurements of desorption rates as well as careful field studies of filtration rates for naturally occurring colloids. This paper is an independent product of the CNWRA and does not necessarily reflect the view or regulatory position of the NRC.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFM.H21D0834P
- Keywords:
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- 1832 Groundwater transport