The MoU was signed in the USA by Secretary of Energy Jennifer Granholm and in Norway by Minister of Trade and Industry Iselin Nybø, and is the next step in a process that began in 2019, when the melt processing method was first discussed on the sidelines of a meeting in Norway. Since then, technical experts on both sides have worked to refine the project roadmap, the DOE said.
HEU - uranium which has been enriched to higher than 20% uranium-235 - has been used to fuel civilian research reactors and in the production of radioisotopes. Even though this is far below the 90% enrichment levels of so-called weapons-grade uranium, HEU is nevertheless seen as a proliferation risk. Various programmes are working to address this, by converting research reactors to non-HEU fuel and ensuring used and unused HEU is secured and downblended - mixed with depleted or natural uranium to bring the uranium-235 content below 20%, rendering it unsuitable for any possible use in weapons.
Norway has in the past operated research reactors including the Halden nuclear fuel and materials testing reactor and the JEEP-II neutron scattering facility. All have now shut down, but the country is one of 22 to hold HEU in the civilian sector. However, Norway's HEU also contains thorium, which poses an extra challenge in its treatment.
The Mobile Melt-Consolidate system is described by DOE as a flexible tool that can treat a wide variety of HEU-bearing materials safely and reliably, including those that are challenging to dispose of by more traditional means. The system will enable the treatment of Norway's HEU at partner facilities, meaning there will be less need to transport the material, and also reducing the amount of material that is ultimately returned to the USA.
The latest agreement lays an important foundation for Norway to get rid of its nuclear weapons-usable material, Nybø said. "Technology developed in the United States is absolutely crucial for us to achieve this. Norway is a pilot country and I hope the technology can also be used by other countries," she added.
"Together with our Norwegian friends and partners, we have taken a major challenge and come up with a creative, innovative solution that will make the world a safer place," Granholm said.
Norway's HEU is the property of its Institute for Energy Technology (IFE), which will carry out the process in collaboration with the government agency Norwegian Nuclear Decommissioning (NND). IFE and NND are working with the DOE's National Nuclear Security Administration and the Savannah River National Laboratory to develop the techniques and equipment, NND said. Permissions will be required from both Norwegian and US regulators before the agreement can be implemented.
Disposing of the HEU will be an important milestone in the clean-up of Norwegian nuclear waste which is expected to last for more than 50 years and cost more than NOK24 billion (USD2.8 billion), Nybø said.