A four-year campaign to repatriate 161 kilograms of highly enriched uranium liquid target residue material (TRM) from Chalk River Laboratories in Ontario, Canada, to the Savannah River Site in Aiken, S.C., has been completed, the National Nuclear Security Administration (NNSA) and Atomic Energy of Canada Limited (AECL) announced on January 12.

The campaign was conducted under the U.S.-Origin Foreign Research Reactor Spent Nuclear Fuel Acceptance Program, established in 1996 to return U.S.-origin spent nuclear fuel and other weapons-grade nuclear material from civilian sites worldwide. Other partners involved in the effort included the Department of Energy’s Office of Environmental Management (EM), Canadian Nuclear Laboratories, Savannah River Nuclear Solutions (SRNS), and Savannah River National Laboratory as well as state and tribal governments.

The TRM is the by-product of the production of medical isotopes from AECL’s now-shuttered National Research Universal reactor. The repatriation of the material, begun in 2017 and completed in 2020, involved 115 separate truck shipments, covering some 150,000 miles, according to the announcements.