US approves new facility design concept to turn nuclear waste into reactor fuel

The Department of Energy (DOE) in the United States has approved the conceptual design for Oklo’s Aurora Fuel Fabrication Facility.

The facility whose conceptual design has been approved will be located at Idaho National Laboratory (INL).

It will help turn used material recovered from DOE’s former Experimental Breeder Reactor-II (EBR-II reactor) into usable fuel for its advanced nuclear power plant. The EBR-II was shut down in late 1994 after 30 years of successful operation.

The conceptual safety design report was first submitted earlier this year to DOE’s Idaho Operations Office, which is responsible for the nuclear safety and regulatory authority for the project.

The approval of the design concept is an important step in demonstrating advanced fuel recycling technologies, a press release by the DOE states.

Recovery from EBR-II fuel

The Aurora powerhouse is a liquid-metal-cooled fast reactor that is designed to operate on both fresh high-assay low-enriched uranium (HALEU) and used nuclear fuel.

The DOE is working to recycle EBR-II spent fuel as part of a larger effort to make HALEU.

HALEU is enriched between 5 and 19.75 percent with uranium-235—the main fissile isotope that produces energy during a chain reaction.

The plan is to recover approximately 10 metric tons of HALEU from EBR-II fuel by December 2028 using an electrochemical process that was perfected over the years at Idaho National Laboratory (INL).

Oklo has been granted access to five metric tons of HALEU as part of a cooperative agreement with INL.

“We are proud of our collaboration with INL and DOE as we move closer to turning on our first commercial plant that uses this recovered nuclear fuel in just a few years,” said Jacob DeWitte, co-founder and CEO of Oklo.

Oklo will continue to work with INL to complete the facility design and obtain DOE approval before the start of construction.

Last month, Oklo finalized agreements with DOE to begin site characterization of their preferred location for the Aurora powerhouse reactor to support their combined license application to the U.S. Nuclear Regulatory Commission.

DOE will retain ownership of the HALEU both during and after its use, according to the press release.

How is HALEU extracted?

The EBR-II operated from 1964 to 1994 and used a metallic alloy fuel containing highly enriched uranium (uranium enriched with more than 20 percent U-235).

To recover this highly enriched uranium, the spent nuclear fuel is prepared and placed into a high-temperature molten salt chemical bath.

An electric current is then used to separate the highly enriched uranium metal from the fission products.

The recovered uranium is cleaned and mixed with lower-enriched uranium to create HALEU.

The uranium is then fabricated into a large circular ingot before being fashioned into low-dose, smaller shapes in a high-temperature furnace.

The smaller ingots can then be used to produce fuel for advanced reactors, like the Aurora microreactor, which will be first demonstrated at the lab as early as 2026.

There is a growing demand for reactor fuel today as countries worldwide seek to shift to nuclear energy.

Turning nuclear weapons into reactor fuel

According to an earlier report, the US is now tu rning its unexploded nuclear warheads into fuel that can be used in modular power stations. The report states that the nuclear warheads are being turned into HALEU at a government facility in Oak Ridge, Tennessee.

At the facility, weapon-grade uranium (which is usually enriched above 20 percent) is first melted and then mixed with depleted uranium to form HALEU.

The supply of HALEU to the US has dwindled ever since Russia began the war with Ukraine. Moreover, earlier this year, the US had signed bipartisan legislation to ban the import of uranium products from Russia.

This creates a problem for the US nuclear power program, as Russia is the only international supplier of nuclear fuel.