It is not an over-exaggeration to say that if the field of nuclear energy is to advance, the one thing it most needs is HALEU. But what is HALEU, and why is it so important?
HALEU stands for High-Assay Low Enriched Uranium. It is a fuel type for nuclear reactors which contains between 5 and 20% of Uranium 235 (U235 being the main isotope used to produce energy in a nuclear reactor’s fission reactions). Currently, all the nuclear reactors in the US run on LEU (Low Enriched Uranium), which only consists of 3-5% Uranium 235.
The reason the nuclear industry is not complacent with simple LEU fuel instead of HALEU is because a large volume of LEU is required to get to the point where the fuel is reactive enough to produce energy in a reactor. This is fine for our current reactors, however the next generation of reactor — promising to be cheaper, safer, longer lasting, and quicker to construct – require fuel to fit into a smaller volume, meaning that this fuel needs to be HALEU to produce energy.
Currently, there are two ways to produce HALEU. Downbending is the most common, where High-Enriched Uranium (HEU) is mixed with uranium of a lower concentration to acquire the right assay. This requires the least technology; however, it relies on the US’ limited stores of HEU. Enrichment is the more sustainable process, where the concentration of U235 in natural uranium is increased to the levels of HALEU. However, this process requires technology which is only possessed by two US companies. Similarly, this technology is strictly regulated, as increasing the concentration of U235 past 20% increases its viability for nuclear weapon use.
Therefore, what is now imperative for the industry is for policy makers and industry leaders to come together and prioritize research, development, and investment in HALEU technology. Taking swift action will provide safer, more efficient nuclear energy, and by investing in this energy the world will be better suited to tackle its climate goals.
Concentrations of Uranium-235 in varying fuel classifications (image: HALEU Energy Fuel)
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