Sustainable nuclear fuel? New method developed to obtain uranium from the sea

Researchers have developed a material that effectively captures uranium ions compared to other methods, opening the door to a more environmentally friendly source of nuclear energy.

Extracting uranium ions from the sea has proven to be a challenge, as the surface area of the materials to do so is not large enough to retain them effectively.

Exploration to obtain new energy sources is an "inexhaustible" topic in the scientific community. However, most of the resources we currently use to obtain it are not, which represents a major challenge on the path to developing clean and sustainable energy.

One of the alternatives explored throughout history is nuclear energy - with pros and cons, like everything in life - and thanks to advances in scientific research and innovation, it has become a candidate to take into account.

This was demonstrated by researchers at Northeast Normal University in China, who developed a material to obtain nuclear fuel sustainably, through the electrochemical extraction of uranium ions from seawater.

Uranium, the rockstar of nuclear energy

The protagonists of this story are the sea, uranium, and a chemical process called electrolysis. To refresh our minds from chemistry classes a little, it is important to remember that this method allows the elements of a compound to be separated using electricity.

Uranium is found in nature in almost all rocks, soil, air and sea and is most often used in nuclear reactors because its unstable and radioactive forms facilitate the fission process, which releases energy in the form of heat and electricity.

Currently, the uranium used in nuclear power plants is extracted from mining sites, where resources are limited. This is where the powerful sea comes in, with all its wealth, to offer a new alternative.

Data from the Nuclear Energy Agency estimates that 4.5 billion tonnes of uranium floats in our oceans in the form of dissolved uranyl ions. This reserve is more than a thousand times greater than that existing on land, but how can we obtain and use it?

"Smart" electrodes for efficient extraction

The answer lies in the emblematic creation of this research: flexible electrodes. These underwater uranium "magnets" are responsible for attracting and capturing ions present in seawater.

Flexible electrodes
The flexibility of these electrodes, built directly on carbon fabric, promises lasting resistance even in the difficult conditions of salty ocean waters. Image credits: ACS Science.

Imagine this as a treasure hunt. We want to trap the uranium ions, but the surface of the available materials is like a plain, there aren't many places to trap them. Therefore, these scientists decided to create an electrode material with many hiding places, like microscopic caves, to trap them more efficiently.

As explained in the article published in the journal ACS Central Science, the team used a flexible fabric made from carbon fibers and applied a chemical treatment to make it "attractive" to uranium ions.

Hopes for a sustainable nuclear fuel

Although the entire chemical process is much more complex than what you can read here, in simple terms, the "magic" (or rather, science) happens when an electric field is applied to these electrodes , where a "chemical dance" occurs reversibly in which uranium ions are transformed into bright yellow precipitates.

According to the researchers, this work offers an effective method for capturing uranium from seawater, so the oceans could become a new supplier of nuclear fuel.

The idea of taking advantage of the inexhaustible wealth of seawater to obtain uranium could revolutionize the way we power our nuclear power plants. This method not only promises environmental sustainability but also reduces pressure on traditional sources to obtain uranium.

News reference :
Zhao R., Zhu.G., et all. Self-Standing Porous Aromatic Framework Electrodes for Efficient Electrochemical Uranium Extraction. ACS Central Science. (2023)