Feature Article

The ongoing effort to convert the world’s research reactors

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.

IRE produces first batch of LEU-based Mo-99

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.