Nuclear Waste Management Program Chemical Processes Projects

Selected Projects

Repository and Transport Chemistry

Column Flow Retardation Experiments: Determination of radionuclide retardation in Culebra dolomite above the WIPP repository using custom-built triaxial flow and gamma spectroscopy systems to directly measure retardation in cores 5.7 inches in diameter. Computer-aided gamma emission tomography quantifies preferential flow and solute diffusion for fractures into dolomite matrix. (Sponsor: Waste Isolation Pilot Plant) See the Sandia Tomography and Radionuclide Transport Laboratory fact sheet (pdf format).

Estimating Actinide Solubilities in Brines: Reduction of actinide solubility data into a consistent set of aqueous species and parameters for Pitzer ion interaction model to determine identities and ranges of solubility-controlling solids in complex brines. (Sponsor: Waste Isolation Pilot Plant) See the Soil-Actinide-Metal Interactions Analysis and Modeling Laboratory fact sheet (pdf format).

Colloid-Facilitated Radionuclide Transport: Characterization of natural colloids, colloids produced by waste degradation, and radiocolloids; development of a model to describe the formation, stability, and transport of colloids in high ionic strength brines associated with the WIPP repository and the overlying Culebra dolomite. (Sponsor: Waste Isolation Pilot Plant) See the Sandia Colloid Geochemistry and Transport Laboratory fact sheet (pdf format) and the Sandia Tomography and Radionuclide Transport Laboratory fact sheet (pdf format).

Contaminant Transport and Containment

Actinide Adsorption on Dolomite and Clay Minerals: Identification and quantification of chemical retardation mechanisms associated with actinide-bearing NaCl brines flowing through clay-bearing dolomite overlying the WIPP repository; application of surface complexation models to describe results. (Sponsor: Waste Isolation Pilot Plant) See the Soil-Actinide-Metal Interactions Analysis and Modeling Laboratory fact sheet (pdf format).

Coupled Reaction/Transport Code: Development and implementation of a mixed kinetic/equilibrium coupled reaction/flow/transport computer code for calculations of contaminant transport in saturated and unsaturated media on a massively parallel computer with 1800 processors. (Sponsor: Yucca Mountain Project and Waste Isolation Pilot Plant) See the Soil-Actinide-Metal Interactions Analysis and Modeling Laboratory fact sheet (pdf format).

Integrated Reactive Transport Experiments: Measurement and prediction of the migration of fluid and tracers through a 6-meter-high x 3-meter-diameter caisson filled with an unsaturated porous medium to validate key geochemical and hydrological assumptions in performance assessment models for high-level waste disposal. (Sponsor: Yucca Mountain Project) See the Soil-Actinide-Metal Interactions Analysis and Modeling Laboratory fact sheet (pdf format).

Development of Models of Contaminant Sorption for Natural Attenuation Studies: Characterization of the surface chemistry of natural and analog materials for laboratory and field tracer studies relevant to Uranium Mill Tailings. Evaluation of natural attenuation of uranium transport by natural barriers. (Sponsor: Uranium Mill Tailings Remedial Action Project) See the Hybrid Lagrangian-Eulerian Model of HydroGeoChemical Transport fact sheet (pdf format) and the Soil-Actinide-Metal Interactions Analysis and Modeling Laboratory fact sheet (pdf format).

Additional Capabilities

Performance, Risk, and Decision Analysis: A systems-based approach to establish goals, prioritize data needs, evaluate risks, quantify uncertainty, incorporate public concerns, and evaluated alternatives. See the PRDA fact sheet (pdf format).