<p>Long-term diffusion of H⁷⁹SeO₃⁻, ⁹⁹TcO₄⁻, ²³⁸UO₂²⁺, and ²³⁷NpO₂⁺ in compacted bentonite was investigated using a combined GAN-DNN and PINN model. The apparent diffusion coefficient (<i>D</i>_a) of HSeO₃⁻ and ReO₄⁻ was measured using a through-diffusion method to validate the generalization of GAN-DNN. Subsequently, the PINN model simulated the spatiotemporal evolution of radionuclide concentrations over 1000-year using the GAN-DNN-predicted <i>D</i>_a as inputs. It reveals that strong sorption effectively restricted ²³⁸UO₂²⁺ and ²³⁷NpO₂⁺ diffusion, whereas anionic exclusion facilitated the penetration of 66%–86% of ⁹⁹TcO₄⁻ and H⁷⁹SeO₃⁻ to penetrate the 0.36&#xa0;m engineered barrier of the Beishan repository in China.</p>