Office of Nuclear Energy

Environmental Assessment Completed for Use of DOE-Owned High-Assay Low-Enriched Uranium Stored at Idaho National Laboratory

January 17, 2019

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Editor’s note: Idaho National Laboratory is distributing this news release on behalf of the U.S. Department of Energy. Any inquiries on this release should be directed to the news media contact listed below.

Press Release

News Media Contact: Tim Jackson (208) 526-8484

For Immediate Release: January 17, 2019


Environmental Assessment Completed for Use of DOE-Owned High-Assay Low-Enriched Uranium Stored at Idaho National Laboratory


The U.S. Department of Energy (DOE) has determined that using DOE-owned high-assay low-enriched uranium (HALEU) stored at Idaho National Laboratory (INL) will not have a significant impact on the environment and is an important tool for advancing safe, economical, low carbon nuclear energy.

In accordance with the National Environmental Policy Act (NEPA), DOE has issued a final Environmental Assessment for Use of DOE-Owned High-Assay Low-Enriched Uranium Stored at INL (DOE/EA-2087).

Based on the analysis in the environmental assessment and after consideration of public comments received on the draft environmental assessment, DOE has determined that using DOE-owned HALEU currently stored at INL to fabricate fuel at INL's Materials and Fuels Complex (MFC) and possibly also the Idaho Nuclear Technology and Engineering Center (INTEC) to support initiatives by U.S. companies to develop and deploy new reactor technologies will not result in a significant impact on the environment. 

With this assessment, DOE released a Finding of No Significant Impact (FONSI) for the proposed action outlined in the document.  DOE published the draft EA for public comment on October 31.  The public comment period ran through November 30.  The final EA and FONSI is posted at the following link:

Background: Since 2000 DOE has used an electrometallurgical treatment process at MFC to refine and down-blend sodium-bonded spent nuclear fuel that contains highly-enriched uranium material generated decades ago in the Experimental Breeder Reactor-II (EBR-II).  A product of this process is a limited amount – approximately 10 metric tons – of high-assay low-enriched uranium (HALEU) that is currently stored at INL.  DOE plans to utilize the capabilities at MFC and INTEC to convert this metallic HALEU into fuel for research and development purposes.  HALEU contains a higher enrichment (by percentage) of uranium-235 – a fissile isotope in nuclear fuel that produces energy – than fuel used in the current fleet of U.S. power reactors.  Conventional light water reactors (LWRs) use low-enriched uranium (LEU) fuel, (3 to 5 percent uranium-235) while HALEU contains between 5 and 20 percent.

Currently, there are no commercial facilities in the U.S. immediately capable of producing HALEU, and several advanced reactor designers have expressed interest in using HALEU fuel with their designs to achieve higher efficiencies and longer core lifetimes.

There are several U.S. companies pursuing advanced reactor designs that would use fuel enriched with higher levels of uranium-235.  These companies need sources of HALEU fuel to conduct the research and development necessary to bring these new technologies to market.  Providing an initial source of this fuel would support this pilot-scale research and development, and aligns with DOE's mission to advance nuclear power as a resource capable of meeting the nation's energy, environmental and national security needs.

Next Steps: With this decision, the federal government will fabricate HALEU nuclear fuel at INL from the lab’s HALEU feedstock.  This will support near-term research, development and demonstration needs of private-sector developers and government agencies, including advanced reactor developers. This is a finite amount of HALEU with limited applications for specific advanced reactor designs but is one of several efforts undertaken by DOE to help ensure the availability of HALEU in support of the U.S. nuclear power industry.  The proposed action identified in the environmental assessment calls for establishing the capability at INL to fabricate HALEU ceramic and metallic fuels from the HALEU produced through the electrometallurgical treatment process currently operating at INL, and by using other small quantities of HALEU stored at INL.  Most of the HALEU to be used for fuel fabrication results from the processing and treatment of used fuel from the decommissioned EBR-II reactor.  Construction and operation of any reactors that propose to use the HALEU fuel will require additional NEPA review.