The US Idaho National Laboratory will provide California-based Oklo with access to recovered used nuclear fuel to aid the company in its efforts to develop and demonstrate the Oklo Aurora microreactor.

Oklo is developing a 1.5MWe small advanced fission technology that can be used in remote or off-grid locations to generate power.

Oklo applied for access to the material via a competitive process launched by INL. It was informed in December of its selection.

The goal is to speed up the deployment of commercially viable micro-reactors by providing reactor developers with access to the material needed to produce fuel for their reactors.

“As the nation’s nuclear energy research laboratory, we are committed to working with private companies and others to develop the technologies that will provide clean energy to the world,” said John Wagner, associate laboratory director for INL’s Nuclear Science & Technology directorate.

In December 2019, Oklo announced the launch of the 1.5MW Aurora clean energy plant with integrated solar panels.

In January, Oklo announced it had received a site use permit from the US Department of Energy (DOE) to build and demonstrate the Aurora technology at INL.

“This award paves the way for an important demonstration of the first Oklo Aurora plant, as well as the ability of advanced reactors to convert used nuclear fuel, that would otherwise be treated for disposal, into clean energy,” said Jacob DeWitte, Oklo co-founder and CEO.

What is HALEU?

Uranium recovered from used fuel is being down blended to produce “high-assay, low-enriched uranium (HALEU) that contains more than 5% and less than 20% uranium-235.

Several US companies, including Oklo, are developing micro-reactor technologies that would use HALEU.

“Many of these designs call for fuels with higher levels of uranium-235 so the reactors can operate for years without having to be refuelled,” Wagner said.

“That is an important attribute since this technology is envisioned to be used in remote areas that can be difficult to access.”

There are no commercial facilities in the United States currently capable of producing HALEU.

However, DOE has established a capability at INL to produce HALEU by processing and treating used fuel from the now-decommissioned Experimental Breeder Reactor-II, which contains high concentrations of uranium-235.

With this supply, INL can produce up to 10 metric tonnes of HALEU for research, development and demonstration purposes.

DOE retains ownership of HALEU during and after use, and the material will stay on the INL site.

The finalisation of access to the HALEU will require a cooperative agreement between INL and Oklo on use of the material.

Wagner said INL’s facilities and ability to supply HALEU enable INL to support Oklo and other entities developing new reactor technologies. He added that INL is continuing discussions with the other applicants to see how the lab can support their efforts.

“We are interested in receiving more proposals from the micro-reactor development community,” he said. “There is an additional quantity of HALEU available to support reactor demonstrations.”

Photo: Aurora microreactor is planned for INL (Credit: Oklo)