SRNL Meets Nuclear Fuel Need for New Types of Reactors
In the United States, there is a push to increase energy security and capacity for numerous needs and applications. Numerous companies are working on developing advanced small modular reactors (SMR) with numerous different reactor and fuel types. However, nearly all of them require High-Assay Low Enriched Uranium (HALEU). HALEU contains a higher percentage of Uranium-235 compared to all other isotopes of uranium used in typical commercial reactors. HALEU typically ranges between 10-19.75% and typical commercial reactor fuel ranges between 3-5% U-235. Unfortunately, today, the US industry projected demand for HALEU far exceeds the available supply. The Savannah River National Laboratory (SRNL) is doing two things to help in providing some of the HALEU needed for these advanced SMRs.
The H-Canyon facility at the Savannah River Site (SRS) previously produced LEU containing 4.95% weight of U-235 from the reprocessing of highly enriched foreign and domestic research reactor fuel for use in a commercial reactor. When the facility stopped producing this LEU, it still had some highly enriched uranium (HEU) in liquid solutions in storage.
Example of uranium nitrate dissolved in solution. Photo by Tom Shehee.
The DOE Office of Nuclear Energy recognized that this material could potentially be “down-blended” to produce HALEU instead of LEU to help solve part of the demand by the new advanced reactor industry. SRNL is performing two key roles to enable this to occur:
- Analysis of Solutions – SRNL analyzed batches of solution from the H-Canyon facility to determine the exact concentration of various impurities and determined that the production of LEU can be readily transitioned to produce 19.75% HALEU solutions from the purified HEU solutions in storage and meet the extensive specifications from the reactor(s). SRNL has performed analysis of over 96 specific isotopes and chemicals that have maximum limits in reactor fuel specifications. SRNL’s extensive suite of analytical capabilities were ideal to perform these numerous analyses.
- Licensing of a Transportation Shipping Package – SRNL is collaborating with the LR-230 cask Certificate of Compliance (COC) holder to perform analysis and develop a Safety Analysis Report for Packaging (SARP). This effort would utilize an existing transportation package typically used for LEU to transport HALEU from SRS to the fuel fabrication facility that will produce new fuel for the advanced SMR(s). SRNL Packaging Technologies brings over 200 years of combined experience in the radioactive material packaging arena and are utilizing knowledge and working relationships with DOE-EMs Packaging Certification Program to help facilitate and provide insight for the SARP submittal to DOE from a non-DOE entity.
Current LR-230 Transportation Shipping Package. Photo provided by Tom Shehee.
SRNL scientist Tom Shehee said, “Most advanced reactors require advanced fuels. Available HEU at SRS has been demonstrated by SRNL to meet the purity needs of select reactor fuels through close work with the reactor fuel vendor. Dependent on a blend scenario, SRNL and SRS can provide the fuel stock needed to completely fuel one of the first advanced reactors to come online in the US.” The target date for the first shipment of HALEU is December 2027, with recurring shipments following the initial delivery. If successful, this project will sustain the early stages of initial advanced SMR testing and deployment while steady supplies of HALEU fuel are developed commercially to satisfy the increasing demand for additional and sustainable power sources in the United States.