Simulation of radionuclides 99Tc and 243Am migration in compacted bentonite.
The distribution coefficients of radionuclides derived from batch experiments are used to evaluate the migration behavior of radionuclides (99)Tc and (243)Am in compacted bentonite after different times. The effects of times, dispersion coefficient, distribution coefficient and pore water velocity on the concentration distribution of (99)Tc and (243)Am in the environment are also calculated from the theoretical migration equation. (99)Tc is poorly sorbed to bentonite and moves quickly into the environment. Migration of radionuclide increases with increasing dispersion coefficient and decreasing distribution coefficient. The effects of water velocity on the migration of Tc and Am are obvious. Most (243)Am is retained in the first several meters, and 20 m of the backfill-compacted bentonites are sufficient to prevent the migration of radionuclide Am from the repository to the environment.
Wang
Xiangke
X
Institute of Plasma Physics, Chinese Academy of Sciences, PO Box 1126, 230031 Hefei, Anhui, PR China. xkwang@ipp.ac.cn
Tan
Xiaoli
X
Ning
Quanli
Q
Chen
Changlun
C