Diffusion characteristics in bentonite are essential to quantify the transport of radionuclides through buffer/backfill materials in waste repositories. This study employs through-diffusion techniques to investigate the diffusion behavior of 99TcO4 − through SPV bentonite with various densities. The apparent diffusion coefficients for bentonite densities are estimated using Marquardt–Levenberg optimization algorithm in the HYDRUS-1D model. Based on the experimental and calculation results, 99Tc could be considered as non-sorbing radionuclides. The data obtained in this study provide a valuable reference for the safety assessment of waste repositories.
- Apparent diffusion coefficient (D)
- Distribution coefficient (K)
- SPV bentonite
- Through diffusion