Post-Closure Safety Assessment of Surface Water Erosion and Hydrological Uncertainties for an Iranian Near-Surface Disposal Site

The long-term safety assessment of Radioactive Waste (RW) repositories is vital for protecting human health and the environment over extended periods. This study presents a probabilistic performance evaluation, including uncertainty analysis, for the Anarak near-surface disposal facility in Iran, with an emphasis on the Surface Water Erosion (SWE) scenario as a dominant post-closure disturbance. The Anarak site, designated as the national repository for low- and intermediate-level RW, was selected through a structured process consistent with the guidelines of the International Atomic Energy Agency (IAEA) and the Iran Nuclear Regulatory Authority (INRA). A detailed SWE scenario was developed to model potential human intrusion, accounting for exposure pathways, occurrence probabilities, and resulting radiation doses to hypothetical future populations. Probabilistic simulations and temporal risk distributions were generated using the AMBER code to capture parameter variability and behavioral uncertainties. The obtained results demonstrate the facility’s robustness against intrusion events and provide essential insights for developing national regulatory frameworks and evidence-based strategies for the sustainable management of radioactive waste in Iran. Results showed that the Anarak region is projected to experience significant warming and a consistent decline in precipitation under all Shared Socioeconomic Pathways (SSP) scenarios, intensifying long-term aridity and surface erosion. Despite these climatic pressures, radiological doses from the near-surface RW disposal facility remain well below regulatory limits over a ۱۰۰۰۰-year horizon, demonstrating a robust long-term safety margin. Crop ingestion is identified as the dominant exposure pathway, while drinking water and milk contribute minimally, although hydrological variability influences mid- to long-term radionuclide transport. All upper-bound doses remain orders of magnitude below public dose limits, highlighting the effectiveness of both engineered and natural barriers under conservative future environmental conditions.

کلیدواژه ها:

Safety assessment ، Radioactive waste ، Surface Water Erosion ، Uncertainty ، AMBER