A representation of what Oklo Inc.'s Aurora Powerhouse will look like |
The California-based company applied for access to the material through a competitive process INL launched earlier this year. Notifications of selection were made to applicants in December 2019. The goal is to accelerate deployment of commercially viable microreactors by providing developers with access to material needed to produce fuel for their reactors.
“We are excited to work with Oklo Inc. and support their needs related to fuel development and microreactor demonstration,” said Dr. John Wagner, associate laboratory director for INL’s Nuclear Science & Technology directorate. “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.”
Jacob DeWitte, Oklo co-founder and chief executive officer, said, “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.” Last month, Oklo announced it received a site use permit from the U.S. Department of Energy to build and demonstrate the Aurora technology at INL.
Uranium recovered from used fuel is being downblended to produce “high-assay, low-enriched uranium,” i.e., HALEU. HALEU is low-enriched uranium that contains over 5% and less than 20% uranium-235, the fissile isotope in nuclear fuel that produces energy during a fission chain reaction.
All 96 nuclear reactors currently operating in the U.S. use fuel enriched with less than 5% uranium-235.
Several U.S. companies are developing microreactor technologies that would use HALEU and need access to the fuel in order to demonstrate and prove out designs.
“Many of these designs call for fuels with higher levels of uranium-235 so the reactors can operate for years without having to be refueled,” Wagner said. “That is an important attribute since this technology is envisioned to be used in remote areas that can be difficult to access.”
However, there are no commercial facilities in the U.S. now capable of producing HALEU.
To address this gap, DOE has established a capability at INL to produce HALEU by processing and treating used fuel from the now-decommissioned Experimental Breeder Reactor-II (the used fuel contains high concentrations of uranium-235 and was being treated and processed for disposal). With this supply, INL can produce up to 10 metric tons 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 finalization of access to the HALEU is pending the establishing a cooperative agreement between INL and Oklo on the use of the material for their microreactor demonstration.
“Building and operating advanced reactors is essential to restoring U.S. leadership in nuclear energy,” said Dr. Ashley Finan, director of the National Reactor Innovation Center. Led by INL, NRIC was established in August 2019 to provide access to resources to accelerate the demonstration of advanced nuclear technology concepts. “The NRIC team is committed to empowering innovators to move their projects from concept to reality. We look forward to working with Oklo on the fuel supply for their first unit and congratulate them on achieving this milestone.”
Reactor demonstration sites at the INL Site are available through a DOE site use permit or other facility use arrangements. INL has a well-developed infrastructure and a well-characterized site with existing facilities and a skilled workforce to support new reactor projects.
Wagner said those factors plus being able 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 microreactor development community,” he said. “There is an additional quantity of HALEU available to support reactor demonstrations.