13,000 Years' Worth of Energy in the Oceans
We have 4.5 billion tons of uranium in seawater. Half of that amount is enough to power nuclear plants worldwide for 6,500 years.
However, unfortunately, the costs of extracting uranium from seawater is three times the current cost of uranium mined from land. That said, researchers believe this source may one day be critical to sustaining our energy needs, and to that end, efforts to extract uranium from the seas began in the 1960's. And our efforts have continued from there.
"For nuclear power to remain a sustainable energy source, an economically viable and secure source of nuclear fuel must be available," said Phillip Britt, technical and outreach leader of the team started by the U.S. Department of Energy (DOE) in 2011. And now, it seems that we have a much cheaper way of obtaining this material.
A Different Kind of Fishing
To begin, extracting seawater uranium is harder than mining from land reserves as it involves a process called “adsorption,” in which atoms, ions, or molecules adhere to a surface. Scientists have been designing different materials to serve as that surface that, when submerged in seawater, will “adsorb” uranium and hold it for extraction.
Keeping these materials cost-efficient is important in relation to keeping the costs of seawater uranium low. Now, the DOE team has developed new adsorbents that brought the costs of seawater uranium extraction down by three to four times and in just five years.
The team created braids of polyethylene fibers that contain amidoxime, a chemical species that binds uranium. Tests show the new material has the ability to hold more than 6 grams of uranium per kilogram of adsorbent in 56 days of submersion in natural seawater.
Experts will convene at the University of Maryland-College Park for the International Conference on Seawater Uranium Recovery in July this year to further explore the potential of seawater uranium as a reliable energy source for the future. And while we may not have everything worked out just yet, things are looking bright.