Oklo, developer of a 1.5-MW passive compact fast reactor, will be the first to receive high-assay, low-enriched uranium (HALEU) nuclear fuel from Idaho //

Oklo recently acquired a site permit to build the design pictured at Idaho National Laboratory facility in Idaho Falls. //

Oklo, developer of a 1.5-MW passive compact fast reactor, will be the first to receive high-assay, low-enriched uranium (HALEU) nuclear fuel from Idaho National Laboratory (INL) to aid a first-of-its-kind demonstration of its Aurora microreactor, which could begin in 2024.

Marking a significant boost for advanced nuclear innovation, which industry experts are banking on to transform nuclear’s future role in a rapidly changing power sector, INL on Feb. 19 said that it will give the Silicon Valley–based advanced nuclear reactor developer access to processed and treated used fuel recovered from the now-decommissioned Experimental Breeder Reactor-II (EBR-II).

Downblended to a uranium enrichment of less than 20%, and still owned by the Department of Energy (DOE), the HALEU will stay at INL’s site in Idaho Falls, Idaho, where Oklo last year received a site use permit to build its Aurora plant. The site use permit, which will be effective for the lifetime of the plant, was the first, and still the only, such permit issued for a non-light-water nuclear reactor in the U.S. //

Several micro-reactors with capacities below 10 MW (by comparison, small modular reactor [SMR] capacities hover between 60 MW and 300 MW) are under development worldwide; one of the biggest hurdles to quick deployment relates to fuel supply.

The Nuclear Energy Institute (NEI) notes that the commercial nuclear fuel industry currently only produces fuel enriched up to 5% by weight of U-235, but that some micro-reactors will use fuel enriched up to 20% by weight of U-235, known as “HALEU.” But because establishing a commercial supply of HALEU would require sufficient demand and a minimum of 7 years to develop fuel cycle infrastructure, the industry trade group has urged the DOE for years to tap into its access of high-enriched uranium and downblend it in the interim to supply HALEU for demonstration purposes.

As Dr. John Wagner, associate laboratory director for INL’s Nuclear Science & Technology directorate, noted on Wednesday, the benefit of using nuclear fuels with higher levels of U-235 is that it allows reactors to operate for years without having to be refueled. “That is an important attribute since this technology is envisioned to be used in remote areas that can be difficult to access.”