Nuclear Waste Disposal

Research in this program addresses the need for secure disposal of the high-level radioactive waste that has been, and will continue to be, produced from nuclear power generation (and weapons production) across the world. After making key contributions to the research and licensing activities for the proposed Yucca Mountain repository in Nevada, Berkeley Lab scientists are now leading research and technology development to enable long-term waste disposal in other host-rock environments, such as shale, salt rock, and crystalline rock, and alternative repository designs.

We focus on the complex coupled subsurface processes–thermal, hydrological, mechanical, and chemical (THMC)–that are triggered by perturbations from repository construction, engineered barrier emplacement, and waste disposal. Advanced methods for evaluating and predicting these coupled processes are tested against experiments conducted at multiple scales, from micro-scale imaging of clay swelling and clay rock damage in laboratory settings to large in situ experiments in subsurface field observatories. What we learn from these studies on coupled processes helps us evaluate the potential long-term impacts on repository site safety. For example, temperature rise from radioactive decay triggers an increase in pore pressure, mechanical deformations, and chemical reactions, possibly generating rock damage and mineralogical changes that can strongly affect radionuclide transport. Without the ability to predict the long-term consequences of these early-stage subsurface perturbations, it is difficult to assess whether natural and engineered barriers can provide safe disposal options over thousands to millions of years.

Supported through DOE’s Office of Nuclear Energy, most of our research centers on waste disposal needs in the U.S., however, we work with partners from around the world and are heavily engaged in international collaborations such as the DECOVALEX Project and the Mont Terri Partnership in Switzerland.