As part of a long-standing collaboration on nuclear nonproliferation, the National Academy of Sciences and the Russian Academy of Sciences held a joint workshop in Moscow in 2003 on the scientific aspects of an international radioactive disposal site in Russia. The passage of Russian laws permitting the importation and storage of high-level radioactive material (primarily spent nuclear fuel from reactors) has engendered interest from a number of foreign governments, including the U.S., in exploring the possibility of transferring material to Russia on a temporary or permanent basis. The workshop focused on the environmental aspects of the general location and characteristics of a possible storage site, transportation to and within the site, containers for transportation and storage, inventory and accountability, audits and inspections, and handling technologies.