The US Department of Energy’s National Nuclear Security Administration (DOE/NNSA) and Atomic Energy of Canada Limited (AECL) have announced the completion of a multi-year campaign to repatriate 161kg of highly enriched uranium (HEU) liquid target residue material from Chalk River Laboratories in Ontario, Canada, to the Savannah River Site in Aiken, South Carolina.

The shipping campaign, which began in 2017 and finished in 2020, involved 115 separate truck shipments. Over the four years of the campaign, the shipments covered more than 240,000 kilometres of safe and secure transportation, equivalent to travelling around the earth six times.

Together, the completion of this shipping campaign, along with the recently completed campaign of used nuclear fuel from the National Research Universal and National Research Experimental research reactors, resulted in the repatriation of more than 367kg of HEU. AECL said this not only reduces Canada’s environmental liabilities and risks, it also serves nuclear security and non-proliferation objectives by reducing the availability of this material.

“Completing this multi-year project with Canada marks another important step in the global effort to minimise the civilian use of HEU around the world,” said Acting NNSA Administrator Dr William Bookless. “This significant achievement could not have been accomplished without the strong cooperation and hard work from all our partners in Canada and the United States.”

Canadian target residue material was the by-product of the production of medical isotopes from AECL’s National Research Universal research reactor, DOE said. Although the reactor is now shut down, for many decades it produced medical isotopes using HEU supplied by the USA.

The target residue material was returned to the USA under the US-Origin Foreign Research Reactor Spent Nuclear Fuel Acceptance Programme, which was established in 1996 with the mission to repatriate US-origin used nuclear fuel and other weapons-grade nuclear material from civilian sites worldwide.

DOE’s Office of Environmental Management, Canadian Nuclear Laboratories, Savannah River Nuclear Solutions, and Savannah River National Laboratory were key partners and played a pivotal role in the success of the campaign. It also relied on the cooperation and aid of numerous state and tribal governments.

In October, AECL and NNSA signed a memorandum of understanding to enable more effective collaboration in the areas of nuclear safety and security and are exploring the repatriation of additional HEU and other materials over the next several years.