ON THE SELECTION OF A COMPUTATIONAL SCHEME FOR THE SAFETY ASSESSMENT OF A NEAR-SURFACE DISPOSAL FACILITY FOR RW: COMPARISON OF MODELS WITH DIFFERENT LEVELS OF DETAIL

The paper compares the migration of radionuclides in the near field of a near-surface radioactive waste disposal facility (NSRWF) calculated using numerical models of different dimensionality (3D/2D/1D) and levels of detail. The required computational resources were also compared based on the number of mesh cells and the total simulation time. The study shows that switching from a detailed 3D model to a profile-type 2D model, while maintaining the configuration detail of the compartment containing the radioactive waste, leads to a moderate (about 12 %) conservative increase in the radionuclide flux intensity to the groundwater level. At the same time, the simulation runtime decreases by approximately two orders of magnitude. However, further simplification by switching to 2D and 1D models with volumetric averaging of radioactive waste activity is not justified as it causes greater calculation errors.

Keywords: radioactive waste, near-surface radioactive waste disposal facility (NSRWF), long-term safety assessment, engineered safety barriers, material degradation, numerical modeling, 3D/2D/1D models.

Anisimov N. A., Sizonenko E. V. On the Selection of a Computational Scheme for the Safety Assessment of a Near-Surface Disposal Facility for RW: Comparison of Models with Different Levels of Detail. Radioactive Waste, 2026, no. 2 (35), pp. 110—117. DOI: 10.25283/258-9707-2026-2-110-117. (In Russian).