The Role of Purpose-built Underground Research Laboratory in High-Level Radioactive Waste Disposal Program

The safe and permanent disposal of high-level radioactive waste (HLW) is a critical challenge for ensuring the sustainability of nuclear energy and securing public acceptance. Since 1997, South Korea has been developing deep geological disposal technologies based on granite as the host rock for HLW repository. With the enactment of the High-Level Radioactive Waste Management Act, the national disposal program is now transitioning from a technology development phase to one focused on site selection and facility construction readiness. This study responds to this policy shift by comprehensively examining the functions and roles of an underground research laboratory (URL) from technical, institutional, and societal perspectives. Technically, the purpose-built URL must be constructed in a single granite formation that replicates actual disposal conditions, and it should serve as a platform for demonstrating key technologies required for construction licensing for the repository—such as site characterization, repository design, engineered barrier system performance evaluation, radionuclide transport modeling, and comprehensive safety assessment. From an institutional standpoint, the site-specific URL should focus on acquiring geologic data specific to the selected site, while the research URL must complete the development and demonstration of disposal technologies in advance to meet the legal target of repository operation by 2060. On the societal front, the purpose-built URL must function as a communication interface between experts and stakeholders, maintaining consisten- cy with prior research and providing demonstration results under conditions analogous to the actual repository site. This is essential for building public trust and enhancing social acceptance. In conclusion, the purpose-built URL must serve as the technological backbone of the HLW disposal program, a critical mechanism for generating the data required for licensing and construction, and a platform for fostering societal confidence. Its timely establishment and strategic operation are essential for the successful implementation of Korea’s national HLW disposal strategy.