Semantics strays uranium energy criticality

Powering nearly 10% of the world's energy needs and roughly 20% of America for over 50 years, nuclear energy is a highly controversial power provider that ticks all the boxes for zero-emission electricity. Much like most contemporary fuels, running these reactors takes something dug from the earth – uranium.

In 2017, the United States Geological Survey was charged with identifying which minerals and metals are critical to the U.S. Its original list of 35 critical minerals, finalized in 2018, included uranium. However, an updated and expanded list of 50 critical minerals published in early 2022 omitted this material necessary for zero-carbon nuclear energy.

Evidently, striking uranium from the original list had less to do with the mineral's proposed criticality and more to do with semantics.

Under the Energy Act of 2020, a "critical mineral" is defined as a non-fuel mineral or mineral material essential to the economic or national security of the U.S., as well as the supply chain, which is vulnerable to disruption. Critical minerals are also characterized as serving an essential function in the manufacturing of a product, the absence of which would have significant consequences for economic or national security.

"Uranium was not evaluated because the Energy Act of 2020 explicitly excluded 'fuel minerals' from the definition of a 'critical mineral,'" the USGS explained in a FAQ sheet associated with the list of critical minerals.

While grammatically accurate, there are those who believe that given our heavy dependence on adversarial nations (historically Russia) for this mineral vital to the U.S. military and zero-carbon energy, it should be ranked high on the list of critical minerals.

"Our uranium import dependence is a case study in how our vital domestic minerals supply chains have atrophied to levels that result in a dire national security risk. We are home to the world's largest nuclear navy and fleet of nuclear power plants, significant uranium reserves, and yet we import virtually all of the uranium we use – half of which comes from Russia, Kazakhstan and Uzbekistan," said National Mining Association President and CEO Rich Nolan. "We must immediately address this glaring vulnerability and source the uranium on which nuclear power functions domestically to prevent this key energy source from being weaponized against our economy."

With uranium meeting all the other critical minerals criteria, simply striking "non-fuel" from the definition would make this nuclear fuel eligible to be put back on the list.

Nevertheless, it has been over a year since the USGS published its official critical minerals list, and even with possible bipartisan legislation through the "Critical Minerals Classification Improvement Act" which would require the USGS to reevaluate the criticality of uranium and other non-fuel minerals for inclusion on an updated list, the bureaucracy does not change the reality of the future risk of this fuel mineral.

Uranium breakdown

Discovered in 1789 by German chemist Martin Klaproth, who named it after the planet Uranus, which had been discovered just eight years prior, Uranium is found naturally as ore dug up from the earth.

While Hollywood and pop culture have caused perceptions surrounding this mineral to be seen as glowing in an eerie greenish or bluish hue (which isn't untrue, although not as exaggerated as radioactive materials emit particles that excite other elements, which then causes a faint light), this weakly radioactive material is actually a silvery, white metal found in seawater and all three broadly defined groups of rocks: igneous, sedimentary, and metamorphic.

Also often seen as some mythical material that's nearly impossible to find due to its rarity, uranium is actually more abundant than precious metals, being nearly 40 times more common than silver and 675 times more common than gold, according to numbers from the 97th edition CRC Handbook of Chemistry and Physics.

For reference, the Earth is estimated to house about 0.075 parts per million silver, and about 0.004 ppm gold, while uranium is about 2.7 ppm.

Furthermore, uranium has a unique trait that makes it quite easy to find compared to most of its elemental brethren, its radioactivity. Despite its abundance, however, the major challenge for commercial uranium extraction is to find areas where concentrations are adequate to form an economically viable mine.

The heaviest of all elements, uranium has three naturally occurring forms or isotopes – U-238, U-235, and U-234 – which are just variations of the atomic nucleus based on the total number of protons and neutrons. Of those specific isotopes, U-235 is most often sought after because its atoms are more easily split apart to create the chain reaction necessary for nuclear fission. However, despite the earlier statement of its ease of discovery, setting aside economic viability, U-235 is relatively rare at just over 0.7% of natural uranium, according to the Energy Information Administration.

Setting aside the politics of its place on the critical minerals list, with only 54 commercially operating nuclear power plants containing 93 power reactors across 28 states, this small number powers roughly one-fifth of the entire country and has done so for over half a century.

So how much uranium is needed to fuel these plants, in particular, the ideal fissile material U-235? About 27 metric tons, or 18 million fuel pellets housed in 50,000 fuel rods, is required for a single 1,000-megawatt-electric capacity pressurized water reactor.

What, then, makes it purportedly critical? Aside from generating about 20% of the power in America, the same isotopic material U-235 is needed in nuclear weaponry.

Uranium list controversy

In 2019, George Washington University's Institute for International Science and Technology Policy published a statement for a hearing on uranium mining and its criticality.

Titled "Critical Minerals: Why is Uranium on the List?" The statement gives a brief history of the beginnings of the criticality dispute of uranium and reiterates that it does not belong on the list.

"The supply of minerals, like energy, should be judged secure when it is reliable, adequate and affordable. Such secure supplies could be domestically or internationally sourced. There are few reputable analysts who would suggest that Canada or Australia might suddenly cut off supplies of uranium to the United States for political or economic reasons. Utilities in the United States purchased 42% of their uranium in 2018 from Canada and Australia, which are two of the top three producers of uranium; Australia has 30% of the known recoverable reserves," the statement said in its concluding section.

Initiated by the Trump administration's direction to develop a strategy to secure reliable supplies of critical minerals at the end of 2017, the Secretary of the Interior at the time began the process of identifying critical minerals.

The argument for its inclusion was the non-fuel aspects of uranium – nuclear weapons.

However, the list published in 2018, which included uranium, was opened to public comments, and more than a third of the 588 comments objected to its inclusion because it is a fuel source.

Hence, it was struck from the list in 2022 as it is not considered critical per the definition.

The reasoning for defensive supply risk was apparently countered by the already substantial reserves contained within the United States.

The total U.S. highly enriched uranium inventory, as of 2013, was calculated at 531.2 metric tons, enough to make more than 23,000 nuclear weapons, which was reasonably suggested that no additional production would be necessary (as of 2019, there are approximately 15,000 nuclear weapons on Earth, and America alone holds almost half that number).

When it comes to zero-carbon nuclear energy, however, American power plants lean heavily on imports for their fuel needs.

According to the EIA, the United States imports nearly 95% of its uranium needs from other countries – 35% from Kazakhstan, 15% from Canada, 14% from Australia, 14% from Russia (as of 2021), 10% from five different countries, 7% from Namibia, and the remaining 5% being "homegrown."

With industry experts, analysts, and insiders, it is certainly known the dependence on 95% of the fuel needed to power 19% of America's energy is anything but a slight risk.

Future is in micro

Foreseeing the transition to clean energy leaning heavily into nuclear energy, research and technology has shifted toward a solution that would not have been possible a decade ago – microreactors.

Expected to be modular, portable, and inhabit a smaller footprint than their larger nuclear counterparts, these microreactors are expected to fill in for remote operations and less-than-ideal renewable locations. While conventional reactors can produce up to 1,000 MWe and are designed to power cities, microreactors will power less than 50 MWe and could supply enough power for roughly 60,000 modern U.S. homes in places far from the grid.

While current production meets requirements now, if several hundred of these microreactors pop up around the country, the demand for uranium will spike, creating a similar issue to what the world is facing for lithium-ion battery materials such as lithium, cobalt, manganese, and graphite.

With a handful of companies predicting their pilot reactors to come online toward the end of the decade, if successful, it will begin to solve the problem of remote energy – however, if the country wants to achieve its net-zero carbon emissions by 2050 solar and wind will not be enough, the intermittent energy dependent on a sunny or windy day will never compare to continuous baseload power that nuclear can provide.