Effect Of Different Ions On Bentonite Minerals

Bentonite is widely used as backfill material for radioactive waste disposal as a natural mineral with high efficiency, stability and low cost. Since the safety evaluation time system of radioactive waste repositories lasts for ten thousand years, the mineral evolution of bentonite after ten thousand years and its effects on the adsorption and retardation properties of Pu are the key points of attention. In this paper, the mineral composition and porosity change of Ke Er Jian bentonite with five Na+/Ca2+/Al3+/K+/Mg2+ ion species in ten thousand year scale were simulated by PHREEQC(3.0) software, the changes of bentonite minerals and their effects on the adsorption properties of nuclide Pu were discussed from two aspects of groundwater transport distance and interaction time, which provided important reference for the safety evaluation of waste disposal.