Saturated Zone Colloid-Facilitated Transport

Technical Report · Tue Dec 18 04:00:00 EST 2001

DOI:https://doi.org/10.2172/836505· OSTI ID:836505

Wolfsberg, A; Reimus, P

The purpose of the Saturated Zone Colloid-Facilitated Transport Analysis and Modeling Report (AMR), as outlined in its Work Direction and Planning Document (CRWMS M&O 1999a), is to provide retardation factors for colloids with irreversibly-attached radionuclides, such as plutonium, in the saturated zone (SZ) between their point of entrance from the unsaturated zone (UZ) and downgradient compliance points. Although it is not exclusive to any particular radionuclide release scenario, this AMR especially addresses those scenarios pertaining to evidence from waste degradation experiments, which indicate that plutonium and perhaps other radionuclides may be irreversibly attached to colloids. This report establishes the requirements and elements of the design of a methodology for calculating colloid transport in the saturated zone at Yucca Mountain. In previous Total Systems Performance Assessment (TSPA) analyses, radionuclide-bearing colloids were assumed to be unretarded in their migration. Field experiments in fractured tuff at Yucca Mountain and in porous media at other sites indicate that colloids may, in fact, experience retardation relative to the mean pore-water velocity, suggesting that contaminants associated with colloids should also experience some retardation. Therefore, this analysis incorporates field data where available and a theoretical framework when site-specific data are not available for estimating plausible ranges of retardation factors in both saturated fractured tuff and saturated alluvium. The distribution of retardation factors for tuff and alluvium are developed in a form consistent with the Performance Assessment (PA) analysis framework for simulating radionuclide transport in the saturated zone. To improve on the work performed so far for the saturated-zone flow and transport modeling, concerted effort has been made in quantifying colloid retardation factors in both fractured tuff and alluvium. The fractured tuff analysis used recent data and interpretation from the C-wells reactive tracer testing complex in the saturated zone of Yucca Mountain. As no data regarding colloid transport have been developed by the Yucca Mountain Site Characterization Project (YMP) for the alluvial system, a theoretical analysis based on studies performed in other alluvial systems is developed. The parameters derived in this AMR are developed in a manner consistent with the PA methodology and can be readily integrated into that analysis.

• Research Organization: Yucca Mountain Project, Las Vegas, Nevada (US)
• Sponsoring Organization: US Department of Energy (US)
• OSTI ID: 836505
• Report Number(s): ANL-NBS-HS-000031, Rev. 00, ICN 01; MOL.20020506.0916, DC32311
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
COLLOIDS
COMPLIANCE
DISTRIBUTION
PLANNING
PLUTONIUM
RADIOISOTOPES
SIMULATION
SITE CHARACTERIZATION
TESTING
TRANSPORT
TUFF
VELOCITY
WASTES
YUCCA MOUNTAIN