The United States and Russia both possess large quantities of nuclear waste, generated during the production of nuclear energy and nuclear weapons. To ensure that this radioactive material remains safely sequestered for tens of thousands of years or more, both countries plan to bury it in deep geologic repositories. However, US and Russian repository design strategies are highly distinct. For example, Russia plans to dilute waste in aluminophosphate glass, package waste in stainless steel containers, and bury waste in hard, crystalline granite gneiss rock. The US approach includes the use of borosilicate glass, multi-component superalloy containers, and porous volcanic tuff or highly-plastic bedded salt. The relative efficacies of these design choices remain uncertain. This represents a unique opportunity for applied, comparative study of various natural and engineered barriers to the release of radioactive materials. US-Russian collaboration and sharing of data on repository performance could provide a better technical basis for the long-term immobilization of nuclear waste.