Global Laser Enrichment (GLE) signed separate, nonbinding letters of intent in June with the two largest nuclear power operators in the United States—Constellation and Duke Energy—to assess potential nuclear fuel supply chain cooperation, including support for GLE’s deployment of laser enrichment technology in the United States. According to GLE president and chief commercial officer James Dobchuk, who delivered a presentation on June 7 at the World Nuclear Fuel Market Annual Meeting, the company’s baseline deployment schedule could be accelerated by about three years (under favorable market conditions) to supply the nuclear fuel market with uranium in a range of enrichment levels in 2027.

The Department of Energy has determined that the sale, lease, or transfer of up to 750 kilograms of high-assay low-enriched uranium (HALEU) per calendar year to support the production of molybdenum-99 will not have an adverse material impact on the domestic uranium mining, conversion, or enrichment industry.

Today’s #ThrowbackThursday post looks at the initial debate surrounding the conversion of research reactor fuel from high-enriched uranium to low-enriched uranium. An article published in the April 1984 issue of Nuclear News (available to all ANS members), titled “NRC studies HEU-to-LEU fuel conversion issue,” was written by the ANS Washington editor John Graham, and brings up several items of interest.

The story: Graham introduces the readers to the growing security concerns around HEU and notes that the issue has its roots in the nonproliferation concerns from the Carter administration that forced the domestic nuclear industry to abandon certain projects—the subject of a #TBT post a couple of weeks ago.

Energy secretary Jennifer Granholm (top photo) and Norwegian minister of Trade and Industry Iselin Nybø (bottom photo, right) hold up signed versions of an MOU on the conversion of Norway’s HEU to LEU. (Photos: NNSA)

The U.S. Department of Energy and Norway’s Ministry of Trade, Industry, and Fisheries have signed a memorandum of understanding to advance a project aimed at eliminating Norway’s high-enriched uranium by downblending it to low-enriched uranium. If the project is successfully completed, Norway will become the 34th country (plus Taiwan) to be considered HEU-free.

In the downblending process, HEU is mixed with depleted or natural uranium to reduce the U-235 concentration to below 20 percent, resulting in LEU, which cannot be used to make an improvised nuclear device (aka “dirty bomb”). According to the DOE’s National Nuclear Security Administration, the challenge with Norway’s HEU has been that much of it is mixed with thorium, making the use of other disposition techniques more problematic.

A closer look: Signed on September 1 by U.S. energy secretary Jennifer Granholm and her Norwegian counterpart, Iselin Nybø, minister of trade and industry, the MOU calls for small-scale downblending activities to begin in 2022 using Norway’s existing infrastructure. It also paves the way for the eventual deployment of the DOE’s Mobile Melt-Consolidate system to complete the work.

The Ghana Research Reactor-1, located in Accra, Ghana, was converted from HEU fuel to LEU in 2017. Photo: Argonne National Laboratory

In late 2018, Nigeria’s sole operating nuclear research reactor, NIRR-1, switched to a safer uranium fuel. Coming just 18 months on the heels of a celebrated conversion in Ghana, the NIRR-1 reboot passed without much fanfare. However, the switch marked an important global milestone: NIRR-1 was the last of Africa’s 11 operating research reactors to run on high-enriched uranium fuel.

The 40-year effort to make research reactors safer and more secure by replacing HEU fuel with low-enriched uranium is marked by a succession of quiet but immeasurably significant milestones like these. Before Africa, a team of engineers from many organizations, including the U.S. Department of Energy’s Argonne National Laboratory, concluded its conversion work in South America and Australia. Worldwide, 71 reactors in nearly 40 countries have undergone conversions to LEU, defined as less than 20 percent uranium-235. Another 31 research reactors have been permanently shut down.

Belgium’s National Institute of Radioelements (IRE) announced on April 30 that it has produced its first batch of commercial molybdenum-99 from low-enriched uranium (LEU) targets. The first batch of Mo-99, whose decay product, technetium-99m, is used in nuclear medicine for diagnostic imaging, was produced for the U.S. health market. IRE said that the conversion to LEU represents a key milestone for the institute in the global commitment to end the civilian use of highly enriched uranium (HEU) for the production of Mo-99.

Advanced reactor cores are being designed for higher efficiencies and longer lifetimes, but to get there, they need high-assay low-enriched uranium (HALEU).

Enriched to between 5 and 19.75 percent fissile U-235, HALEU is packed with nuclear potential. It can be used as a feedstock for the demonstration of new fuel designs, from uranium alloys to ceramic pellets and liquid fuels. Those fuels can enable advanced reactor and microreactor demonstrations. Operating light-water reactors could potentially transition to HALEU uranium oxide fuels for extended operating cycles and improved plant economics.