UNDERGROUND RESEARCH LABORATORIES ARE KEY TO DEVELOPING AND COMMUNICATING GEOLOGIC REPOSITORY SAFETY CASES

Underground research laboratories (URLs) are integral to the repository program of countries pursuing geologic disposal of spent nuclear fuel (SNF) from nuclear power plants or solidified high-level radioactive waste (HLW) from the reprocessing of nuclear fuel. URLs enable research and development (R&D) activities to be conducted under subsurface conditions and at scales relevant to specific repository environments and support the development of a safety case. A safety case is a collection of logic and evidence that demonstrates that a nuclear waste repository meets the performance requirements defined by the appropriate regulatory authorities. Repository programs in other countries use URLs to explain to the public and regulators the technical bases underlying their safety cases, periodically reassess knowledge gaps and define new activities to strengthen the technical bases and demonstrate the technology that will allow implementation of the proposed safety concept.

Until 2010, the U.S. Department of Energy (DOE) had a URL at Yucca Mountain, Nevada, and since 2012, has funded disposal R&D activities in several URLs located in Europe and Asia. The U.S. Nuclear Waste Technical Review Board (NWTRB) evaluates the technical and scientific validity of DOE activities related to the management and disposal of SNF and HLW and provides objective expert technical advice on nuclear waste management to Congress and the Secretary of Energy. The NWTRB evaluated the role of URLs in DOE’s disposal R&D program and made several recommendations to DOE including that DOE should make systematic use of URL R&D results to regularly update generic repository safety cases that can be easily understood by and demonstrated to the public, including safety cases relevant to direct disposal of dual-purpose canisters in different host rocks. The NWTRB also recommended that DOE should pursue one or more domestic URLs to advance the development and demonstration of disposal concepts and provide a platform for training the next generation of U.S. scientists, engineers, and skilled technical workers.