THE SECOND SAUDI INTERNATIONAL CONFERENCE ON NUCLEAR POWER ENGINEERING (SCOPE-2)

The rapid expansion of nuclear energy has intensified the need for effective and secure methods of disposing of high-level radioactive waste (HLW). Deep geological repositories (DGRs) and deep borehole disposal (DBD) are two leading strategies for isolating high-level waste (HLW) from the biosphere. Despite their technical potential, both approaches face unresolved issues, including geological uncertainties, degradation of engineered barriers, and societal resistance. Underground research facilities (URFs) play a critical role in addressing these challenges by enabling in situ evaluation of host rock properties, engineered barriers, and radionuclide migration under repository-relevant conditions.
Global efforts in DGR and URF development have produced notable facilities such as Onkalo (Finland), Cigéo (France), and Beishan (China), each contributing to the advancement of thermal-hydraulic-mechanical-chemical (THMC) models and safety validation. However, technical limitations persist, including microcracking in host rocks, copper corrosion, and bentonite alteration, exacerbated by complex long-term environmental conditions. Non-technical barriers such as regulatory delays, political shifts, and community mistrust further complicate repository implementation.
Recent innovations focus on integrating digital twin systems, autonomous monitoring, and real-time stress sensors to enhance predictive modelling and safety assurance. Repurposing abandoned infrastructure, such as oil wells, has also emerged as a cost-effective and geologically feasible alternative for URF deployment. Concurrently, stakeholder engagement models, such as consent-based siting and community-driven monitoring, offer pathways to increase public acceptance and trust.
URFs remain indispensable to the future of HLW management, providing critical data and validation frameworks that are essential for effective management. The convergence of scientific innovation, regulatory clarity, and societal participation is crucial to achieving sustainable and ethically grounded solutions for nuclear waste disposal.