Progress report on colloid-facilitated transport at Yucca Mountain: Yucca Mountain site characterization program milestone 3383

Colloid-Facilitated Transport of Low-Solubility Radionuclides: A Field, Experimental, and Modeling Investigation

“…Sampling groundwater colloids without introducing artifacts has been difficult and significant effort has been invested in developing techniques designed to minimize contamination (Buddemeier, 1986;) (See chapter 2). Many things can inadvertently alter the sample and lead to erroneous results including: over-pumping of the aquifer, contamination of well construction materials, surface contamination in the collected sample, and poor handling of the sample after collection that alters the water chemistry Degueldre et al, 1996). For example, most pump rates used to collect groundwater are high and result in over-pumping or overestimating the concentration of colloids (Puls et al, 1992) and possibly biasing samples toward larger particles .…”

Repository Safety Strategy: Strategy for Protecting Public Health and Safety after Closure of a Yucca Mountain Repository, Rev. 1

“…The stability of these true radiocolloids under repository conditions has not yet been determined. Some information suggests that under repository conditions, these colloids would be unstable, or would occur in low enough concentrations so as not to provide a means to effectively transport radionuclides (Triay et al 1995;Triay and Degueldre 1997).…”

In Drift Corrosion Products

“…The corrosion products will alter the sorptive properties of the EBS and affect transport of radionuclides within the drift. Colloids generated from steel and alloy corrosion products that strongly sorb radionuclides could provide additional radionuclide transport capabilities (Meike and Wittwer 1993;Triay et al 1995). Because of the planned use of large amounts of steel and alloys in the potential repository, these types of colloids could have a large source capacity relative to the natural iron-oxyhydroxide colloids fluxing through the drift.…”