Hassanizadeh SM ; Leijnse A ; Vries WJ de ; Stapper
RAM
56 p
in Dutch
1990
Toon Nederlands
English Abstract An integral part of the safety assessment of nuclear
waste disposal is the study of nuclide transport in the geosphere. Such
studies are commonly made possible by means of mathematical models.
Mathematical models serve as a powerful tool for prediction of release of
waste into the geosphere, movement of water and contaminants through the
geosphere, and calculation of doses of radioactive material reaching the
biosphere. Groundwater in the aquifers surrounding and overlying salt
formations often contains a high concentration of salt. To study certain
flow and transport processes under such extreme conditions, a series of
laboratory experiments have been carried out. Calculated and measured
breakthrough curves agree very well for low concentration experiments. For
high concentrations, however, a poor agreement is obtained with the
classical formulation of coupled flow and transport in porous media. It
appears that the basic conceptual theory needs to be modified for high
concentration gradients. This report describes the set-up of the
experiments, methods and materials used, and data acquisition and analysis.
It also contains results of simulation of experiments with METROPOL-3 and
gives an account of the necessary modifications to the basic conceptual
theory for high-concentration-gradient situations. It appears that a
nonlinear dispersion theory satisfactorily simulates high- as well as
low-concentration-gradient experiments.
