Examples of Kemakta’s work on radionuclide transport are given below. Radionuclide transport calculations are a fundamental component of performance assessment (PA). The final calculations for PA assume that radionuclide sorption is Kd-controlled during transport, and so it is important that the Kd values selected are validated carefully using appropriate tools. However, the importance of non-Kd processes for radionuclide migration also needs to be evaluated in detail to support the PA. In this, advanced modelling techniques are applied to specific scenarios. A PDF version of each report can be accessed by clicking on the title.
Radionuclide transport report for the safety assessment SR-Site (2010). SKB TR-10-50.
In this study, flow channeling phenomena were modeled so that they included diffusion into stagnant zones and solid solution kinetic and equilibrium partitioning. This was the first PA to consider the impact of diffusion in stagnant zones. Also, the kinetics of solute uptake to solid solutions is not usually considered in reactive transport modelling. The model results were used to support the SR‑Site safety assessment transport report.
Model codes: Matlab/PHREEQC, COM23, FARF31 and MARFA
Bedrock Kd data and uncertainty assessment for application in SR-Site geosphere transport calculations. Updated 2011-10 (2010). SKB R-10-48
This study involved cation exchange modelling to support the Kd values recommended for SR-site specific groundwater conditions. This was the first attempt to provide “transfer factors” to extrapolate Kd values from laboratory experiments to relevant field groundwater compositions. The model results were applied directly in the SR‑Site safety assessment transport modelling.
Model codes: Matlab/PHREEQC