NNSA’s Office of Material Management and Minimization (M3) works globally to minimize the civilian use and production of highly enriched uranium (HEU), a weapons-usable nuclear material. To support this effort, M3’s Office of Conversion works to convert research reactors from HEU fuel to low-enriched uranium (LEU) fuel. To date, the program has converted or verified the shutdown of 104 research reactors worldwide (plus five medical isotope facilities for a total of 109).
Many of the remaining research and test reactors operating on HEU today have unique designs, fuel configurations, and demanding performance requirements that cannot be met with an existing, regulatory-approved LEU fuel. M3, DOE’s National Laboratories, and international partners are designing, demonstrating, and qualifying new high-density LEU fuels to convert these reactors while maintaining their unique capabilities that support a wide variety of science and technology research in areas such as medicine, industry, defense, education, and training. This also ensures that the future fleet of new research reactors will have LEU fuels capable of performing at the highest level to meet the demands of the future.
This effort continues a history of developing and qualifying new LEU fuel systems to convert research reactors. Previous work includes qualification of LEU silicide fuel (leading to the U.S. NRC’s NUREG 1313), LEU zirconium-hydride for TRIGA reactors, as well as the development and testing (although not qualification) of a uranium-molybdenum dispersion fuel to convert Russian-designed IRT reactors.
M3 has also developed, designed, and tested a new LEU fuel (uranium-molybdenum monolithic) that is in the final stages of fuel demonstrations before applying for regulatory approval for use. This final stage involves a comprehensive series of irradiation tests of the LEU fuel that will provide data and confirm the performance and key material properties of the LEU fuel. This information will be summarized in fuel qualification reports that will be submitted to obtain regulatory approval for use of the new LEU fuel system. In addition to this new first of a kind monolithic fuel, M3 has partnered with the European HERACLES consortium of reactors and fuel manufacturers to develop, design, test, and qualify new high-density LEU fuels including a new uranium-molybdenum dispersion fuel, as well as a higher-density uranium-silicide dispersion fuel.
These new LEU fuels will be used to convert research reactors in the United States and internationally, including:
- U.S. High Performance Research Reactors (USHPRR)
- Massachusetts Institute of Technology Research Reactor (MITR)
- University of Missouri Research Reactor (MURR)
- National Bureau of Standards Reactor (NBSR)
- Advanced Test Reactor and its associated critical assembly (ATR and ATR-C)
- High Flux Isotope Reactor (HFIR)
- Belgium: Belgium Reactor 2 (BR2)
- France: Laue Langevin Institute (ILL) High Flux Reactor (RHF)
- Germany: Heinz Maier-Leibnitz Research Neutron Source (FRM II)